THE CHARACTERISTIC OF YOUNG ATHLETE

Introduction

An implied plea is made for coaches to cease applying adult-relevant coaching

practices to this population of athletes. It is obvious that the ways the body energizes

activity and performs skilled movements in young people is different to those, which

occur in adults. This issue does not touch on the psychological factors involved in this

group of individuals even though they are distinctly different to those of adults.

A case has been made to coach mature female athletes appropriately and differently to

males. This particular issue may seem to promote a paradox to that principle. For

practical purposes, pre-pubescent athletes can be trained without considering gender

differences. While there are gender differences in children, they are relatively minor and

small when compared to those existing in mature individuals. Adolescence is a time when

gender differences appear. When they emerge depends largely upon the stage of

maturation of individuals. Since females mature earlier than males, they warrant special

attention to their unique characteristics and factors and the provision of gender-specific

sport programs earlier than males. Developmental differences in adolescence make it

particularly difficult to categorize specific coaching principles that can be applied in a

manner that is similar in conceptual definition to that which is possible for children and

adults.

Young athletes are physically developing, from early childhood to late adolescence. This

means they have different capabilities for, and adaptations to, exercise and for this

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reason, young athlete training programs should not be just scaled down versions of adult

training programs.

More young people enjoy sports than ever before. Athletic participation has increased in

grade schools, high schools and community programs.

Young athletes have special needs. Because their bodies are growing, they often require

different coaching, conditioning, and medical care than more mature athletes. It is

important to examine the special requirements of young athletes to better prepare them

for the competitive pressures and physical injuries that can come with increased sports

activity.

Statistics demonstrate the increased popularity of sports among young people. Fifty

percent of boys and 25 percent of girls between the ages of eight and 16 compete in an

organized sports program sometime during the year. Three-fourths of junior high schools

and middle schools have competitive interscholastic sports programs. At the high school

level, there are 32 male and 27 female competitive sports with 7,000,000 high school

students participating. Beyond organized sports programs, millions more compete and

participate in physical education classes, church and community intramural programs,

and other recreational athletic activities.

A host of factors has contributed to the awakening of interest in health, conditioning and

sports. The media impact on youth has elevated talented college and professional athletes

to heroic levels. The multimedia message on these sports heroes may confuse young

athletes by creating unrealistic expectations. The early return to competition by

2

professional athletes following an injury creates the impression that athletes often heal

faster than the rest of us. However, peer pressure and the economic and social forces

exerted on school coaches to win may lead to decisions that are not truly in the best

interests of a child's health, growth and development.

The fastest rate of growth occurs in the first two years, the growth rate then slows until

the adolescent spurt when the growth rate increases again. The adolescent spurt last

approximately two years and takes place, on average, at 10 to 12 years for girls and 12 to

14 for boys. Growth rate then decreases until full height is reached.

Muscle mass increases steadily until puberty, at which point boys show faster muscle

growth. The hormonal changes at puberty also affect body composition in terms of fat.

• At birth, both boys and girls have around 10 to 12% body fat

• Pre-puberty, both girls and boys still have a similar 16 to 18% body fat

• Post-puberty, girls have around 25% body fat due to high serum oestrogen, which

causes the hips to widen and extra fat to be stored in the same area.

• Post-puberty, boys have 12 to 14% body fat

There is a science of the child and the adolescent in exercise. It behooves all coaches to

become familiar with the content and principles of those sciences so that maturing

individuals can be provided with healthy and sound experiences in their sporting

endeavors.

3

Young Athletes are Different

The growing athlete is not merely a smaller version of the adult. There are marked

differences in coordination, strength and stamina between a youth and an adult. In young

athletes, bone-tendon-muscle units, growth areas within bones, and ligaments experience

uneven growth patterns, leaving them susceptible to injury

Increases in body size may be due to fat and not muscle, causing marked differences in

strength. Too often unfair competition occurs between boys of 100 pounds of baby fat

and peach fuzz versus 200 pounds of muscle and mustache.

Grade school students are less likely to suffer from severe injury because they are smaller

and slower than older athletes; when they collide or fall, the forces on their

musculoskeletal system are usually not high enough to cause injury. On the other hand,

high school athletes are bigger, faster, stronger and capable of delivering tremendous

forces in contact sports.

Coaches bear a prime responsibility in developing their young athletes and watching for

early signs of physical problems (such as pain or limp). They often recognize severe

injuries because their athletes show signs of pain and can't continue playing.

Coaches may have more difficulty spotting less severe injuries, however, because the

pain is low grade and the athlete often ignores it. Repeat injuries may turn into overuse

conditions which can put the athlete on the sidelines for the rest of the season.

4

Many sports injuries in young athletes, particularly elbow and knee injuries are caused by

excessive, repetitive stress on immature muscle-bone units. Such repetitive overuse can

cause fractures, muscle tears or bone deformity Fortunately, such injuries are uncommon,

and usually prolonged pain is an early warning sign.

Coaches, parents and players should provide protection for the young athlete through

proper conditioning, prompt treatment of injuries and rehabilitation programs.

Conditioning programs usually strive to make the young athlete "physically fit" by

improving muscle strength, endurance, flexibility, and cardio respiratory fitness.

The coaches and parents also are responsible for creating a psychological atmosphere that

fosters self-reliance, confidence, cooperation, trust and a positive self-image. Young

athletes must learn to deal with success and defeat in order to place events in a proper

perspective. Some coaches and parents go too far in analyzing player performance. The

promotion of the "win at all costs" ethic has both short-term and long-term detrimental

effects on impressionable young people.

This issue is divided into four topics: children, adolescents, growth, and application

criteria.

5

CHAPTER 1

THE GROWTH OF PHYSICAL CHARACTERISTICS IN MALE AND FEMALE CHILDREN

" . . . there is an increasing awareness and concern on the part of parents and

educationalists about the possible harmful effects on children who participate at a

progressively younger age and with ever-increasing intensity in sports competitions

designed by and for adults."

(Borms, J, 1986.)

1.1 Exercise and Growth

Boys and girls differ in stature. Girls experience their adolescent growth spurt and

peak height velocity on average about two years earlier than boys. The growth spurt of

boys lasts longer and is somewhat more intensive than in girls. Subsequently, boys tend

to catch up and then pass the growth period of girls.

In any random sample, there is a remarkable range in body sizes in both sexes.

Still tenable hypothesis : Epiphyseal growth may be stimulated by physical

activity to an optimal length but excessive and prolonged pressure can retard linear

growth.

6

There is no convincing evidence to support the view that regular and natural exercise

promotes an increase in body size.

There have been no studies in children of effects of training on bone growth and its

mineral contents although exercise does promote these factors (actually reverses

demineralization) in adults.

Height and Bone

During the first two years of life there is a rapid increase in height, with 50

percent of adult height reached by the age of two years. This is followed during

childhood by a progressive decline in the rate of change in height. Just prior to puberty,

there is a marked increase in the rate of change in height, followed by an exponential

decrease until full height is attained at a mean age of 161/2 years in girls and 18 years in

boys. These trends are illustrated in Figure 1.

There is a wide variation in the average age at which the different bones reach full growth

or maturity, ranging from the preteens to the early twenties. On the average, girls achieve

full maturity of their bones several years before boys. Exercise is regarded as essential for

proper bone growth. While exercise appears to have little or no influence on the growth

in length of long bones, it does increase the width of bone, gives the bone greater tensile

strength, and lays down more mineral in the bone matrix.

7

Figure 1 : Changes in the rate of change in weight and height with age in both males and females between the ages of 6 months and 18 years

Figure 2 : Epiphyseal slippage at the proximal head of the femur in the left leg of an eight-year old girl injured while playing competitive soccer (from Murray Robertson, MD., Tucson, AZ ).

In this chapter, we are interested in the process of bone growth primarily for the

purpose of understanding the potential for injury. An injury to an immature bone could

8

result in the premature cessation of growth, resulting in a shorter bone. Disruption of the

growth of the femur, as an example, would lead to a difference in the lengths of the two

legs, with the involved leg being much shorter. The greatest concern is with the potential

for injury at the epiphyses, since a fracture at the epiphysis and growth plate could disturb

the blood supply and disrupt the growth process. Fortunately, such injuries are relatively

rare and seldom occur in sports. In one study of 31 epiphyseal injuries, only 23 percent

were sports-induced, the remainder resulting from falls and vehicular accidents (Larson,

1974). Figure 2 illustrates a slipped epiphysis of the distal head of the femur in an

eight-year old girl, whose presenting symptoms were initially diagnosed as a groin pull.

The injury occurred during a championship soccer match.

Figure 3 : An example of a separation of the epiphysis (Larson, 1974)

One type of serious epiphyseal injury that occurs in athletics is called traumatic

epiphysitis. One form is "Little Leaguer's elbow," a condition resulting from repetitive

strains to the medial epicondylar epiphysis of the humerus. According to Larson, studies

have shown that 12-year-old boys can throw a baseball up to 70 mph. This can cause a

9

sudden pull on the epiphysis, which anchors the tendons of the involved muscles, which

may result in its separation (see Figure 3). The repetitive stress of throwing may produce

an inflammatory response, referred to as traumatic epiphysitis. In a well-controlled study

published in 1965, Adams found epiphysitis by X-ray examination in all 80 pitchers in a

group of 162 young boys, while only a small percentage of the nonpitchers and the

control group of nonplayers exhibited similar changes. Subsequent studies have not

substantiated this initial study, in that a much lower percentage of those with epiphysitis

have been reported.

Larson and McMahan (1966) reviewed 1,338 consecutive athletic injuries seen by a

group of four orthopedists in one major sports medicine practice. They reported that 20

percent of these injuries were in the age range of 14 years and younger. Only six percent

of all injuries in 15-year-olds and younger involved the epiphysis. They also stated that

this type of injury does not always result in crippling, or permanent, trauma and that early

recognition is important.

Of all the sports, competitive baseball appears to be the most dangerous because of its

potential for serious injuries, which largely result from the pitching motion. Some leagues

have replaced the pitcher with a pitching machine. This would seem to be the only

sensible approach until the youngster reaches an age at which pitching is not a major

source of injury. Pop Warner football and the other competitive sports and activities have

a relatively good record with regard to bone injury. While the potential for injury in

football is generally considered high, apparently the small size of the player, the

10

matching of children by size, and good protective equipment provide a relatively safe

environment for the young football player. Inappropriate equipment, and mismatching

players by size and ability, creates an environment with a high potential for injury.

Muscle

From birth through adolescence there is a steady increase in the muscle mass of

the body that parallels the youngster's gain in weight. The total muscle mass in males

increases from 25 percent of body weight at birth to 40 percent or more in the adult.

Much of this gain occurs at puberty, when there is peak acceleration in the development

of muscle, which corresponds to the sudden, approximately tenfold increase in

testosterone production. Girls do not experience this period of rapid acceleration at

puberty, but their muscle mass does continue to increase at a rate considerably below that

of boys. Once a girl reaches puberty, her estrogen levels increase, which promotes the

deposition of body fat. The increases in muscle mass with age appear to result primarily

from hypertrophy of existing fibers, with little or no hyperplasia (increase in fiber

number). The hypertrophy is the result of increases in the myofilaments and myofibrils.

As bones grow in length, muscle length increases. Increases in the number of sarcomeres,

which are added at the junction of muscle and tendon, and increases in the length of

existing sarcomeres, result in this increase in muscle length. When the female reaches 16

to 18 years of age and the male 18 to 22 years, the muscle mass is at its peak, unless it is

increased further through exercise, diet, or both. The muscle mass will remain relatively

stable from this age through the ages of 30 to 40 years, if physical activity levels remain

constant and do not decrease. With older age, there is a decrease in the total muscle mass,

11

which may result from both atrophy of selected muscle fibers, generally Type 11, and a

decrease in the number of muscle fibers. The decrease in fibers may be the result of nerve

fiber degeneration.

Fat

Fat cells form and fat starts to deposit in these cells early in the development of

the fetus and continues indefinitely. Each fat cell has the ability to increase in size at any

age, from birth to death. Initial studies suggested that the number of fat cells became

fixed early in life, thus it was considered important to keep the total fat content of the

body low during this early period of development. In this way, the total number of fat

cells would be minimized, and the chances of extreme obesity as an adult would be

greatly reduced. More recent evidence, however, suggested that fat cells can continue to

increase in number throughout life (Bjorntorp, 1986). The most recent evidence suggests

that as fat is added to the body, existing fat cells continue to fill with fat to a certain

critical level, at which point new cells are formed from pre adipocytes of undifferentiated

cells. Thus, it is important to maintain good dietary and exercise habits throughout life!

Figure 4 : Changes in triceps and subscapular skinfold thickness (subcutaneous fat) with age, from 2 years to 18 years (data from the NHANES-I, National Center for Health Statistics)

12

The degree of fat accumulation with growth and aging will depend entirely on your

dietary and exercise habits, in addition to heredity. While heredity is unchangeable, diet

and exercise can be manipulated to either increase or decrease the fat stores. At birth, 10

to 12 percent of your body weight is fat, and by the time you reach physical maturity, the

fat content reaches 15 to 25 percent of the total body weight for males and females,

respectively. Figure 4 illustrates the relationship between subcutaneous fat at the triceps

and subscapular sites, and age for males and females, with subcutaneous fat being

representative of total body fat.

Nervous System

As the child grows, he or she develops better agility and coordination, which is a

direct function of the development of both the central and peripheral nervous systems.

During the early stages of development, myelination of the nerve fibers must be

completed before fast reactions and skilled movement can occur. Conduction velocity

along a nerve fiber is considerably slower if myelination is absent or incomplete. Late in

life, as aging progresses, conduction velocity along a nerve fiber may tend to slow. Speed

of reaction and movement both decrease with aging due to an increased conduction

velocity in the peripheral nervous system, both sensory and motor.

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1.2 General Performance and Physiological Function.

In almost all of the physiological systems, function appears to improve until

maturity, or shortly before, and then plateaus for a period of time, before starting to

decline with old age. This section will focus on changes in motor ability, strength,

cardiovascular function, aerobic capacity, and anaerobic capacity that accompany the

growth and development process.

Motor Ability

The motor skill ability of boys and girls generally increases with age, from six

years to 17 years, although girls tend to plateau at about the age of puberty for most items

tested. This is illustrated in Figure 5. These improvements are the result of the

development of the neuromuscular and endocrine systems that occur with growth and

development, and secondarily to the increased activity patterns of these children. The

plateau observed in the girls at puberty is most likely explained by two factors. With

puberty, the increase in estrogen levels, or in the estrogen/testosterone ratio, leads to a

greater deposition of body fat. As fat levels increase, performance tends to decrease.

Probably of greater importance, however, is the fact that many girls assume a much more

sedentary lifestyle coincident with puberty. As these girls become less active and more

sedentary, their motor abilities tend to plateau.

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Strength

Changes in strength with age parallel the increases that occur in muscle mass.

Peak strength is usually attained by the age of 20 years in females and between 20 and 30

years in males. Rather marked increases in strength occur at the time of puberty in the

male resulting from sudden changes in the hormonal status, up to tenfold increase in the

androgens, which lead to increased deposition of muscle. Brooks and Fahey (1984) have

also made the important observation that the extent of the development and performance

of muscle is dependent on the relative maturation of the nervous system. High levels of

strength, power, and skill are impossible if the child has not reached neural maturity.

Since myelination of nerves is incomplete until sexual maturity, the neural control of

muscle function will be limited. Figure 6 illustrates changes in leg strength in a group of

boys from the Medford Growth Study followed longitudinally for a period of 12 years,

from the age of eight years to 18 years. There is a noticeable increase in the rate of

strength gain at about the age of 12 years, which is coincident with the onset of puberty.

Similar longitudinal data for girls is not available. From cross-sectional data, however,

girls experience a more gradual increase in strength, and do not exhibit a marked change

in the rate of strength gain with puberty.

Figure 5 : Gains in leg strength with age in young boys followed longitudinally over a 12-year period. Data from the Medford Growth Study (from Clarke, H. H).

15

Figure 6 : Changes in means of performance scores of boys and girls from ages 6 to 17 years (data from the President's Council on Physical Fitness and Sports).

16

Basal Metabolic Rate (BMR)

The BMR, or lowest metabolic rate that the individual attains during a 24-hour

day, decreases at a rate of approximately three percent per decade from the age of three

through 80. Longitudinal studies that have followed the same individuals over 20-year

periods, or longer, suggest a more conservative decrease of only one to two percent per

decade. Up to the age of 20 to 30 years, this decrease is assumed to reflect a more

efficient metabolism. Beyond 30 years of age, this decrease could be a result of the

decrease in lean body weight. It would be interesting to determine if physically active

individuals, particularly those performing heavy-resistance exercises on a regular basis,

have this same decrease in BMR. Likewise, it would be interesting to determine whether

increasing muscle mass through heavy-resistance weight training would increase the

BMR in older people. An increased BMR might reduce the degree of fat accumulation

that seems to accompany the aging process.

Pulmonary Function

A number of cross-sectional studies have demonstrated that lung function is

markedly altered by age. During the period of growth, the static lung volumes, as well as

the volumes determined during functional pulmonary tests, increase to the time of

physical maturity. Shortly after reaching this peak, however, there is a gradual reduction

with age. Vital capacity, FEVi.o (the greatest volume of air that can be exhaled in the

first second of a forced vital capacity test), residual volume, and forced expiratory flow

rate, all exhibit a linear increase with age, up to the age of 20 to 30 years. These changes

17

are associated with the growth in size of the pulmonary system, which parallels the

growth patterns of the child.

The changes in these volumes and flow rates are matched by the changes in maximal

ventilatory capacity during exhaustive exercise. Maximal expiratory ventilation (ft max)

will increase with age to the point of physical maturity, and then it will decrease with the

aging process. From cross-sectional data for males, the VE max, for four- to six-year-old

boys, will average about 40 liters per min, increase to from 110 to 140 liters per min at

full maturity, and decrease from 60 to 80 liters per min for 60- to 70-year-olds. Females

follow the same general pattern, although their absolute values will be considerably lower

for each age level, due, primarily, to their smaller stature.

Cardiovascular Function

A number of changes occur in cardiovascular function as the child ages. There is

a linear decrease in maximal heart rate with age. Young children, under ten years of age,

frequently exceed 210 beats per min, while the average 20-year-old has a maximal heart

rate of approximately 195 beats per min. It has been estimated that the maximal heart rate

decreases by slightly less than one beat per year as the individual ages. The submaximal

heart rate response to the same absolute rate of work on a cycle ergometer is higher in the

child compared to the adult. This higher submaximal heart rate is a partial compensation

for a lower stroke volume which results from a smaller heart size and smaller total blood

volume. As the child ages, heart size and blood volume will increase parallel with

increases in body size, and stroke volume will thereby increase for the same absolute rate

18

of work. The higher submaximal heart rate does not totally compensate for the lower

stroke volume in the child, thus the cardiac output will be somewhat lower in the child

compared to the adult for the same absolute rate of work. The child, to maintain adequate

oxygen uptake for these submaximal levels of work, further compensates by increasing

the arterio-mixed venous oxygen difference. These submaximal relationships are

illustrated in Figure 7. Blood pressure at rest and during submaximal levels of exercise is

lower in the child compared to the adult, but will progressively increase to reach adult

values during late pubescence.

Figure 7 : Submaximal heart rate, stroke volume, cardiac output and arterio-venous oxygen difference in boy and men at fixed rates of oxygen uptake.

19

Blood flow to active muscle may be increased during exercise in the child as compared to

the adult, due to a reduced peripheral resistance.

During maximal levels of exercise, the smaller heart of the child limits the maximal

stroke volume that can be achieved. While the child has a higher maximal heart rate, this

higher rate is unable to fully compensate for the lower maximal stroke volume, thus

maximal cardiac output is lower in the child. This will be a limitation in the performance

of high absolute rates of work, such as a fixed rate of work on a cycle ergometer, since

the capacity for oxygen delivery will be less. However, for high relative rates of work,

where the child is only responsible for moving his or her body mass, this will not be as

serious a limitation.

Maximal Aerobic Capacity

The purpose of the basic pulmonary and cardiovascular adaptations that are made

in response to varying levels of exercise, or rates of work, is to accommodate the need of

the exercising muscles for oxygen. Thus, the increases in pulmonary and cardiovascular

function with growth suggest that aerobic capacity, or VO2 max, experiences a similar

increase with age. Robinson, in 1938, demonstrated this phenomenon in a cross-sectional

sample of boys and men ranging in age from 6 to 91 years. He found that V02 max

attained its peak value at 17 to 20 years of age and then decreased as a linear function of

age. Others have subsequently reported results that confirm these original observations.

Studies of girls and women have shown essentially the same trend, although the female

20

starts her decline at a much younger age, probably due to an earlier assumption of a

sedentary lifestyle. The changes in V02 max with age, expressed in liters-min-', are

illustrated in Figure 8.

Figure 8 : Changes in maximal oxygen uptake with age with values expressed in liters - rnin-'.

When V02 max values are expressed relative to body weight, a considerably different

picture emerges (see Figure 9). Values appear to change very little in boys from the age

of six years to young adulthood. For girls, however, there appears to be little or no

change from six years to 13 years, but from 13 years to young adulthood there is a

gradual decrease in aerobic capacity.

Figure 9 : Changes in maximal oxygen uptake with age with values expressed relative to body weight (ml - kg -' - min – 1)

21

How do these changes in aerobic capacity with growth affect the child's performance?

For any activity that requires a fixed rate of work, for example, cycling on an ergometer,

the low V02 max expressed in absolute liters-min-' will present limitations to endurance

performance. However, for activities where the body weight is the major resistance to

movement, as in distance running, the child should not be at a disadvantage, since his or

her V02 max, expressed relative to body weight, is already at or near adult values. Does

this mean that a child should be able to run as fast as an adult? The answer to this

question is "no," due to basic differences in mechanical efficiency between the child and

the adult. For the same speed on a treadmill, the child will have substantially higher

submaximal oxygen consumption. If the child's lactate threshold occurred at the same

relative oxygen consumption as an adult (the same percentage of their respective ~702

max), the child would be running at a much slower pace.

Anaerobic Capacity

The child has limited ability to perform anaerobic types of activities. This is

demonstrated in several ways. First, the child is not able to achieve adult concentrations

of lactate in either muscle or blood for submaximal, maximal, and supramaximal rates of

exercise. It has been suggested that this reflects a low concentration of the key, rate

limiting enzyme of glycolysis, phosphofructokinase. This is also apparent in the inability

of the child to achieve high respiratory exchange ratios during maximal or exhaustive

exercise-the maximal values are seldom above 1.10, and are frequently below 1.00.

Lactate threshold, however, when expressed as a percentage Of V02 max, does not

22

appear to be a limiting factor in the child, as his or her values are similar, if not somewhat

higher, than those of similarly trained adults.

Anaerobic mean and peak power output, as determined on the Wingate anaerobic test is

also lower in the child as compared to the adult. Figure 10 illustrates this fact on 306

males who performed the Wingate test with both arms and legs. Mean power output was

the average power output for the entire 30-second test. Peak power output was the highest

power output attained during any one five-second interval during the 30-second test.

Anaerobic power does increase with growth and development, even when the values are

expressed relative to body weight, as watts-kg-'.

Figure 10 : Mean (MP) and peak (PP) anaerobic power changes with age, expressed in absolute terms (watts) and relative to body weight (watts-kg-').

23

CHAPTER 2

ENERGY SYSTEM OF YOUNG ATHLETES

2.2 Aerobic Power

Aerobic power increases with age during childhood in both sexes and is quite

similar. Girls hardly differ from boys in the prepubertal period but, from the age of 14

years on their aerobic power are significantly lower by about 15%. The maximal aerobic

performance capacity in girls reaches a plateau from 14 years onwards while in boys it

increases up to the age of 18 years. Thus, even though the aerobic capacity is fully

developed aerobic performance continues to improve. That is because other growth

factors, such as larger levers, greater musculature, etc. are still developing and govern the

effectiveness and mechanical efficiency of aerobic activities.

The potential effect of endurance training programs on VO2max is not consistently

shown in studies involving children. Endurance training has been shown not to effect

aerobic capacity before 11 years. After the age of 12, an improvement in VO2max has

been shown in males, particularly swimmers. This suggests that there is an increased

trainability of the heart and circulatory system around puberty in males. However, studies

at the International Center for Aquatic Research in Colorado Springs have shown that

swimmers' aerobic capacity reaches its ceiling level at the time of onset of the adolescent

growth spurt.

It takes a lot of intense aerobic training to produce shifts in aerobic factors in children.

The apparently high threshold of a stimulus for training effects on VO2max in children is

24

probably related to their naturally active lives. The stresses induced by short-term

training are probably small when placed in the context of the overall activities of

children. VO2max improvements are similar to those reported for adults when the

training volumes and intensities are very high.

VO2max training effects are larger in swimmers probably because it is an unnatural and

specific activity (the starting point is much lower than those of other everyday activities).

Short-term training programs (such as in schools) probably should not even consider

improving endurance in pre-pubertal children.

Boys and girls 7.6 to 10.3 years have shown a significant improvement in running

performance (up to 18%) but without an obvious increase in VO2max. The

improvements are probably due to motor coordination and running technique. This

suggests that if VO2max is the only criterion for aerobic fitness it may be misleading.

Implication : In pre-pubertal children, the gains from endurance training will

largely result from improvements in mechanical efficiency NOT a large change in

physical aerobic power. Thus, for endurance improvements, an emphasis on the

techniques of performance is more beneficial than the programming of assumed

physiological stimulations of training.

There is no difference between children and non-trained adults relative to physical

capacity at the anaerobic threshold.

In children, cardiovascular adaptation is efficient and similar to adults; muscle structure

is identical to adults; and glycogen storage mechanics and values are similar to adults.

25

2.3 Anaerobic Capacity

Unlike aerobic capacity, the anaerobic capacity of children expressed per Kg of

body weight is much smaller than adults. It is lowest in children and increases

progressively with age in both boys and girls. Little to nothing is known about the

trainability of anaerobic capacity in children.

The ratio of aerobic : anaerobic metabolism contribution to exercise differs between

children and adults.

"Most researchers agree that a paced 3000-metre run . . . . is less strenuous for

children than a vigorous 200-800-metre run . . . . instructions on running speed must be

given, otherwise both a 3000-meter run and a 200-800-metre run may be equally

strenuous since lactate accumulation depends, among other things, upon running

intensity. Even longer distance runs (e.g., 30-min duration) for children are more

justified than vigorous short sprints as they may also lead to the maintenance of optimal

body composition . . . . it is not the duration but the intensity of the effort which could

prove harmful."

(Borms, J. 1986.)

Implication : Children are endurance animals and are best suited to adapt to

aerobic exercises. Frequent and stressful stimulation of anaerobic metabolism will be

particularly fatiguing and if overdone, could be harmful. Children will fatigue rapidly in

anaerobic work when compared to their response to endurance work. The major content

26

of swimming program for children should be "distance" work at a comfortable level

(anaerobic threshold and lower) with an obvious concentration on skill, smoothness, and

mechanical efficiency.

2.4 Strength

"In the prepubescent age, muscle weight is about 27% of the total body weight

and the effect of training on muscle hypertrophy is small so that strength gains are

perhaps more the result of an improvement in coordination . . . . After sexual maturation

[the onset of the adolescent growth spurt], muscular development is influenced by

androgenic hormones and the percentage of muscle weight then increases to over 40%."

(Borms, J. 1986)

Since the increase in testosterone production in adolescent children is markedly higher in

boys than girls, boys will become stronger faster and to a higher degree.

Implication : If strength training is to be done with pre-pubescent children,

exercises should involve submaximal resistance, such as one's own body weight, light

dumbbells, or medicine balls. Sophisticated and restrictive weight exercises, particular on

machines, are useless for strength-limited children. General, whole-body activities are

more important and beneficial than the same exercises used for post-pubescent athletes.

27

1.5 Speed

" . . . a yearly increase in sprint velocity has been noted from age 5 years until

age 16 years for boys, and until age 13 to 15 years for girls. The rate of development of

speed seems to accelerate in two phases. A first phase occurs around 8 years of age, both

in boys and girls . . . Probable reasons for this are the development of the nervous system

and improved coordination of arm and leg muscles. A great variety of exercises involving

the whole body should be offered to children to stimulate improvement of this ability. A

second phase . . . occurs around 12 years of age for girls and between 12 and 15 years

for boys . . . related to the increase in body size with age and the concomitant increase in

muscular strength, power, and endurance . . . slightly higher performance levels for boys

than for girls until the onset of adolescence when the differences favoring the boys

becomes more marked."

(Borms, J. 1986)

1.6 Flexibility

There is a gradual increase in flexibility with age as measured on the sit-and-reach

test. However, generalization is not clear because of the absence of studies and data that

take into account growth spurts and anthropometrical size changes (e.g., longer arms

produce a better sit-and-reach measure).

1.7 Coordination and Skill Learning

28

Most authors agree that the sensitive skill learning period is between 9 and 12

years. Very early training may produce learning of a less economical nature. Later

starters would soon catch up. One must not confuse performance with skill. Early

maturers will compensate, usually advantageously, for lack of skill with strength and

leverage.

Implication : Up to the age of 8, children should enjoy a variety of stimulating

activities to develop a general base of physical and movement aptitudes. From then on,

more detailed instruction in particular skills can be entertained but against a background

of general stimulation. It has been shown that, in general, children who specialize early

will lack the "background" development of capacities for flexible maximum responses in

the later years, and higher performance categories, of participation.

1.8 Early Maturation

" . . . early maturation in boys is an advantage in some sports, but the opposite

applies in girls . . . there is an apparent delay in maturity in sports where females who

maintain preadolescent physique seem to have an advantage. An ordering of sports on a

continuum from participants demonstrating early maturation through to late maturation

might be as follows: alpine skiing, field events, swimming, synchronized swimming, track

events, diving, figure skating, gymnastics . . . "

(Borms, J. 1986)

29

Successful female athletes display physical characteristics that favor good performances

(more mesomorph, less ectomorph); successful young female athletes have similar

somatotypes to older successful athletes.

" . . . There is a trend towards increase linearity in these athletes and this linear physique

characterizes the physical attributes of late maturing girls."

(Carter, J. E. 1981).

Early maturing girls undergo a socialization process which does not motivate them any

more to excel in physical exercise. On the other hand, late-maturing girls tend to be

socialized into sports participation. Late-maturing girls are older chronologically when

they attain menarche and have not yet experienced the social pressures regarding

competitive athletics for girls and/or are more able to cope with the social pressures.

1.9 Children and Adults

The child differs in some aspects from the adult and is comparable in others. The

training principles appropriate for both groups are generally different. That is because not

only are developmental factors different, but so are the skill/experiences that are taken

into each participation realm. Intensive training to acquire specialized sports skills at too

early an age has more disadvantages than advantages. Early specialization is by definition

achieved at the expense of developing a broader base of fundamental movement skills

30

such as balance, agility, and coordination, and usually occurs at the expense of learning

other sports.

Early specialization, in a sense, produces the physical equivalent of a specialist who has

little competency outside of the specialty.

TRAINING THE YOUNG ATHLETE

Must special consideration be given to the young athlete when developing

individualized programs of training? Generally, the youngster will adapt well to the same

type of training routine used to train the mature athlete. This section will look at the

specific areas of strength, aerobic and anaerobic training, addressing those issues that are

of concern to this age group.

Strength

One area of major controversy with regard to muscle development in youngsters

is the use of weight training to increase muscular strength and endurance. For many

years, young boys and girls were discouraged from using weights for fear that they might

injure themselves and prematurely stop their growth processes. Studies on animals

suggest that heavy-resistance exercise would lead to a stronger, broader, and more

compact bone. However, since it is nearly impossible to load these animals to the same

extent as youngsters, it has not been practical to design an experiment that accurately

31

defines the risks associated with heavy resistance exercise in youngsters. It would appear

that the potential for injury and structural damage from heavy-resistance exercise is

extremely low, but since the future of the youngster is at stake, it is appropriate to take a

conservative approach until additional studies can be conducted. Thus, a program using

low weights and high repetitions would be preferred to one using high weights and low

repetitions. One of the safest techniques for strength training in youngsters would be to

use the isokinetic concept, in which resistance is matched to the force applied, so that the

youngster does not have to contend with actual weights, such as a barbells and

dumbbells.

It has been suggested that since young, prepubescent boys have relatively low circulating

androgen levels, there is no reason to expect them to be able to benefit from strength

training at this early age. Several recent studies have demonstrated that prepubescent

boys can not only participate in this form of activity safely, but they can also gain

substantial increases in strength. In a study conducted by Sewall and Micheli (1986),

prepubescent boys and girls took part in a nine-week progressive, resistance-strength

training program, 25 to 30 minutes per day, three days a week. They experienced a mean

strength increase of 42.9 percent compared to a 9.5 percent increase in a nontraining

control group. Weltman and his colleagues (1986) followed 26 prepubertal males with a

mean age of 8.2 years through a 14-week strength training program using isokinetic

techniques with hydraulic resistance. Isokinetic strength increased between 18 and 37

percent in these young boys. Only one injury was reported which the authors felt was

related to the strength training routine. As a result, the boy missed three training sessions.

32

An additional six subjects reported injuries resulting -from activities of daily living,

independent of the strength training program. No boy demonstrated any evidence of

damage to epiphyses, bone, or muscle as a result of strength training.

Aerobic and Anaerobic Training

Do prepubescent boys and girls benefit from aerobic training (training to improve

the cardiorespiratory systems)? This has also been a highly controversial area as several

early studies indicated that training prepubescent children did not affect changes in V02

max. Interestingly, even without significant increases in V02 max, these children had

substantial improvements in performance, for example, reduced time for running a fixed

distance. From the research studies that have been conducted to date, it seems appropriate

to conclude that there will be only small increases in aerobic capacity with training in

youngsters ten years of age and younger, even though their performances in aerobic

activities are improved. More substantial changes in'~02 max appear to occur once the

child has reached puberty. The reasons for these findings are not well-defined at this

time. Since stroke volume appears to be the major limitation to aerobic performance in

this age group, it is quite possible that further increases in aerobic capacity are dependent

on growth of the heart. Anaerobic training does appear to improve the anaerobic capacity

of children. Following training, children have increased resting levels of creatine

phosphate, ATP, and glycogen, and they have an increased activity of

phosphofructokinase, and increased maximal lactate levels in the blood.

33

PSYCHOLOGICAL ASPECTS

Is formal, organized competition or participation in vigorous physical activity

damaging to the emotional health and psychological development of the athlete? For the

mature athlete, this presents no major problem, but many parents, educators, physicians,

and psychologists have expressed concern over the potential for undesirable emotional

experiences in the developing young athlete. The question has been raised whether

children who compete in formal, highly-organized activities are likely to develop

undesirable behavior patterns or psychological damage as a result of the pressures to win

and be successful by adult standards. Does the 11 year-old boys competing on the all-star

Little League team experience pressures and situations that could lead to immediate or

future behavior or emotional problems?

Only limited research has been conducted in this area. Skubic (1954, 1955) studied both

Little League and Middle League (13 to 15 years of age) baseball athletes in a small

community in California. Using parents' opinions and the Galvanic skin-resistance

measurement, she found essentially no difference between the athletes in formal

competition compared to those who participated informally in physical education

softball. There were few athletes who had any serious emotional problems that could be

related to the stress of competition. Generally, her results suggested that formal

competition at this age level was not detrimental to the child, but actually facilitated

social and emotional growth.

34

On the other hand, Sherif, et al. (1961) conducted a fascinating study, which has been

referred to as the "Lord of the Flies" or "Robber's Cave" experiment. In this study, a

group of boys at summer camp were divided into two subgroups. During the initial part

of the study, the groups were separated during much of the day, but they had periods of

interaction. No problems between the groups developed during this part of the study. For

the second phase of the study, the groups were put into situations where they were always

in competition with each other in camp life, as well as in sports and games, both for

recognition and for tangible rewards. During this phase, members of the individual

groups developed strong allegiances to their own group and extreme hostility toward the

other group. Night raids, cheating, and other forms of aggressive behavior began to

develop. This phase of the study was discontinued when several members of both groups

started developing serious psychological disturbances. During the third, and last, phase of

the experiment, an attempt was made to bring the two groups back together in

cooperative ventures, removing all forms of competition between the groups. It took

considerable time to achieve the goal of working in a genuinely cooperative effort.

From these examples, it can only be concluded that competition can have both positive

and negative influences on the emotional development of the youngsters. Of major

importance is the climate in which the competition takes place. If the climate is such that

winning is the only goal and parents are allowed to say and do whatever they please

without giving the child sound guidance in coping with the stress of the situation, the

child will be likely to have a negative experience. In short, the nature of the child's

experience will depend almost entirely on the local situation. If competition is organized

35

with this in mind, and the goal is to satisfy the needs of the child and not the adult, the

experience should be positive and facilitate sound emotional growth and psychological

development.

36

CHAPTER 2

ENERGY CAPACITIES ONLY WEAKLY RELATED IN CHILDREN AND ADOLESCENTS

Only a weak relationship was found between the aerobic and anaerobic capacities

in children and adolescents classified according to maturational age.

Implication : The type of physical performance capacity exhibited by pre-pubertal

children is not a sound index for predicting post-pubertal athletic capabilities. One

cannot, with any moderate degree of confidence, conclude that a successful pre-pubertal

sprinter will be just as successful in sprinting during adolescence. Performance capacities

are weak predictors of later performances and therefore, are not sound bases for talent

identification.

37

CHAPTER 3

PRE-PUBERTAL CHILDREN HAVE ONE ENERGY SYSTEM?

In both male and female children, those who performed best anaerobically also

performed best aerobically. In children, energy systems appear to be able to compensate

for each other and "cross" the line of supposed specialization. There is no evidence of

metabolic specialization in pre-pubertal children.

Implication : When planning training and fitness programs for pre-pubertal children,

there is no point in differentiating between anaerobic and aerobic work. General fitness

will be accommodated within the capabilities of children of this age.

38

CHAPTER 4

TESTING PHYSICAL FITNESS IN CHILDREN

Field tests to measure the capability of children to do certain classifications of

physical work are just as valid as are laboratory assessments. The 50 yd run is a good

measure of anaerobic capability and the 1600 yd run valuable for aerobic assessment.

Implication : The fitness of pre-pubertal children is measured satisfactorily by

convenient simple running tests.

4.1 How Much Weight-Training For Children?

It was found that weight training two times per week was equally effective for

developing strength as was three times.

Implication : In growing children and youths, there is no need to do a "lot" of

weight-training. Two times per week appears to be quite sufficient to develop significant

changes. More frequent sessions do not produce any more development.

39

CHAPTER 5

STRENGTH TRAINING RESPONSE OF CHILDREN

The effects of eight weeks of strength training followed by eight weeks of

detraining in children (7-12 yr) were evaluated. Sessions were conducted twice per week.

A group matched for age and maturity level served as a control group.

The trained group improved leg extensions (53.5%) and chest press (41.1%). Controls

improved 7.9%. Vertical jump and sit-and-reach flexibility did not change in any

significant manner. During detraining, losses in strength were evident after four weeks,

with the legs losing more strength than the upper body.

Implication : Twice-per-week strength training is sufficient to dramatically

improve the strength of children over gains that would be expected by maturation.

Detraining occurs with inactivity as with any trained effect. Weight-bearing muscle

groups (legs) were seen to detrain more than the upper body.

5.1 Strength Training Effects Different For Prepubescent Males And Females

The effect of an isoinertial (isotonic) strength training program on isometric

strength in prepubescent females was investigated. An experimental and control group

40

were used. The training response was different to that of previously published work with

prepubescent males. Throughout the change and detraining phases of the study, there was

no change in isometric measures or positions.

Implication : The specificity of strength training may operate differently in

prepubescent females than in males.

5.2 Strength Training In Children

Early studies and theorists have generally supported the view that resistance

(strength) training in prepubescent children is ineffective. This study performed a meta-

analysis on published studies that used Ss with a maximum age of 12 years for girls and

13 years for boys.

From 25 studies which showed an increase in strength in children, 9 were sufficiently

detailed and controlled to assess common magnitudes of effect. Generally, improvements

of between 13 and 30% were obtained. The size of the effect was modified by the various

variables associated with resistance training (loads, frequency, type of exercise, sessions

per week, etc.).

Three studies were found that demonstrated no change. The authors advise that since

studies which show changes are published with a much higher frequency than those

41

which yield no differences, the overall meta-analysis could be biased (Falk, B., &

Tenenbaum, G. 1996).

Generally, adults and adolescents demonstrate greater absolute increases in strength but

prepubescents demonstrate an equal or greater relative percentage gain. No differences in

gains were found between genders in children. As with almost all strength programs rates

of gain are highest at the start and largely due to learning to do the skills involved in a

more economical manner.

Studies in this area have not been designed particularly well. Many factors need to be

controlled. Simply giving a weight program and measuring changes does not shed light

on effects because of the many confounding variables associated with this activity.

Implication : Strength training programs are effective with prepupbescent

children. The dynamics and limits of this form of training have not been determined for

this population. Coaches are advised to be cautious when employing this training activity.

42

CHAPTER 8

AEROBIC TRAINING IS LIMITED IN CHILDREN

Cardio-respiratory function develops throughout childhood. Lung volume and

peak- flow rates steadily increase until full growth. For example, maximum ventilation

increases from 40 L/min at five years to more than 110 L/min as an adult (Wilmore &

Costill, 1994). This means that children have higher respiratory rates than adults, 60

breaths/min compared to 40 breaths/min for the equivalent level of exercise (Sharp,

1995). The ventilatory equivalent for oxygen is also higher in children, VE/V02 = 40 for

an eight-year-old compared to 28 for an 18 year-old. This means that children have

inferior pulmonary functions to adults.

Cardiovascular function is also different for children. They have a smaller heart chamber

and lower volume than adults. This results in a lower stroke volume than adults, both at

rest and during exercise. Chamber size and blood volume gradually increase to adult

values with growth. Children compensate for the smaller stroke volume by having higher

maximal heart rates than adults have. For a mid-teenager, max heart rate could be more

than 215 beats/min compared to a 20 year-old whose max heart rate will be around 195-

200 bpm (Sharp, 1995).

However, the higher heart rates cannot fully compensate for the lower stroke volume and

so children's cardiac output, measured in L/min, is lower than adults (Wilmore & Costill

1994). Children can compensate a little again, as their arterial venous oxygen difference

43

is greater. This suggests that a greater percentage of the cardiac output goes to the

working muscles than in adults (Wilmore & Costill, 1994).

An in-school 12-week aerobic training program was designed for girls (N = 24)

and boys (N = 13). Three 30 min training sessions were offered per week.

It was found that training changes occurred but were of less magnitude than

would be expected of adults. This finding supports the general literature contention that

children are more limited in aerobic training adaptations than adults.

Implication : Prepubescent children should be trained aerobically but

expectations for improvement should be less than that afforded adults.

8.1 Chidren Have Only General Metabolic Responces

The objective information in female youth energy responses in sprint activities is

quite scant. However, it appears that children who specialize in sports do not exhibit a

specialized metabolic response. They appear to be "metabolic non-specialists." Children

do not seem to display the wide variations in metabolic response capabilities seen among

adults, nor do they appear to have high levels of response in any one metabolic system.

Implication : It may be a false premise to concentrate on developing specific

energy systems in children as young as 12 years of age. Rather, what exercises they do

44

should be energized by training responses to a variety of stimuli which, if applied to

adults, would not produce specialized metabolic responses.

8.2 Training Effects In Young Boys (11-13 Yr)

Boys (11-13 yr, N = 18) from different sports (4 endurance runners, 7 tennis

players, 4 weightlifters, 3 sprinters) were divided into two groups according to a "fast"

group (M = 59% Type II fibers) and a "slow" group (M = 60.6% Type I fibers). A variety

of tests were performed. Fibers were divided into (a) Type I slow-twitch oxidative, (b)

Type IIA fast-twitch oxidative, and (c) Type IIB fast-twitch glycolytic.

The fiber distributions were as follows:

Category Fast Group Slow Group

Type I 40.8% 60.4%

Type II 59.2% 39.4%

Type IIA 36.5% (61.6%) 22.8% (57.9%)

Type IIB 22.7% (38.4%) 16.6% (42.1)%

45

Source : Mero, A., Jaakkola, L., & Komi, P. V. (1991). Relationships between muscle fibre characteristics and physical performance capacity in trained athletic boys. Journal of Sports Sciences, 9, 161-171.

Few significant differences were revealed. Reaction time to sound and choice reaction

time were faster for the fast group and it also had a greater rate of force development. A

weak significant relationship between Type II fiber area and blood lactate levels (r = .53)

was revealed. There were no differences between running velocity, maximal oxygen

uptake, or anaerobic characteristics.

The similarity in aerobic capacity stemmed from the training program of the boys

(general endurance within each sport). The Type IIA fibers made up the inherent

difference by adapting to oxidative work. It was shown that even though the "fast" boys

inherited 66.5% more Type II fibers, a greater percentage of them switched to oxidative

functioning so that between the groups the fast group had 77.3% and the slow group

83.2% of fibers functioning oxidatively. This suggests that in young boys, the

adaptability of fibers allows individuals to perform a variety of tasks, particularly of an

endurance nature.

Implication : In young boys, the adaptability of the inherited fiber distributions

to different types of training makes measures of aerobic or anaerobic capacity relatively

useless as a performance predictor. However, reaction time and power development rates

may discriminate between fast- and slow-twitch dominant pubescent boys. This is about

all that can be used to identify capacity talent that will not be revealed in a current

sporting performance.

46

8.3 Early Learning / Training Is Not Necessarily The Best

Certain periods in the life of young children are marked by times of particular

sensitivity. For example, in McGraw's (1935) attempts to modify the behaviors of

identical twins by teaching them a number of physical activities, some credence to the

"appropriate times for learning" postulation was presented.

The onset of walking was not affected by preemptory practice or help. It is a

phylogenetic behavior that is largely "programmed" into the natural development

timing of the youngster. It cannot be "speeded-up."

Roller skating, an unnatural activity but closely allied to walking, developed

almost in concert with walking itself.

A number of other activities were actually made worse by early practice because

of bad skill habits developed or the negative occurrences associated with the

learning experience.

Implication : Starting a sporting experience at a very young age is not

necessarily advantageous. It would seem that if one was to design development in a sport,

the following are appropriate:

47

Provide a wide variety of activities so that generalized basic gross skills are

developed.

Pay little attention to skill intricacies, instead being satisfied with gross motor

movement patterns.

Provide much activity that leads to successful outcomes.

Avoid at all costs, the implementation of adult rules and sport dynamics, instead

providing activities appropriate for the social, intellectual, and development

stages of the participants.

There are critical periods for learning that vary from sport to sport. For each kind of

coordinated muscular activity there is an optimum for rapid and skillful learning.

48

CHAPTER 9

CARDIOVASCULAR RESPONSES IN CHILDREN AND ADULTS

Submaximal cardiovascular responses at a given rate of work on a treadmill and

cycle ergometer were compared between children (M = 12; F = 12) and adults (M = 12; F

= 12).

Cardiac output was significantly lower, but heart rate, total peripheral resistance, and

stroke volume were significantly higher, in children of both sexes than comparable adults

in both forms of exercise.

The smaller amount of muscle mass in children would be stressed to a relatively greater

extent than in adults. Greater metabolic by-products and heat would be produced per unit

of muscle which would: a) increase the amount of oxygen liberated from hemoglobin in

the muscle, and b) increase vasodilation of the arteries entering the muscles. Both these

effects contribute to a higher a-vO2 difference in children in exercise (Turley, K. R., &

Wilmore, J. H. 1996).

49

Implications : Submaximal cardiovascular responses are different between

children and adults. These differences are related to smaller hearts and less total muscle

volume in children. These differences are observable irrespective of the form of exercise.

CHAPTER 10

SPRINT AND ENDURANCE TRAINING IN CHILDREN

Groups (sprint, endurance, and control) of children were trained for 20 minutes in

a specific program four times a week for six weeks. The science of developmental

physiology can supply answers to certain important questions regarding the training of

children. One such question is: should children perform adult-type endurance training in

reduced quantities, or should they be performing a different type of training that is

tailored to their physiology?

Science suggests the latter is true and that the type and intensity of training that is most

effective for developing endurance in the young will be different from that used by

adults. The average adult model for endurance training involves an intensity of 75% of

max heart rate maintained for 20 to 30 minutes. If this is performed 3 to 5 times a week,

then the average adult can expect a 25% improvement in VO2max. Both an increase in

stroke volume and an improvement in O2 respiration and metabolism in the working

50

muscles due to increased capillaries, mitochondria and enzyme activity cause this

improvement in fitness.

Several training studies have been carried out on children to find out what effect a

cardiovascular (CV) training programme will have on fitness levels. In general, the

research shows that if children follow a 3 to 5 times a week routine of at least 20 minutes

continuous activity for 12 weeks, then improvements in VO2max of 7 to 26% is possible.

On average, though, and the results of some of the better-controlled experiments support

this, a child can expect a 10% improvement in VO2max after following an 'adult-like' CV

training programme. The consensus from the research is that children can improve their

aerobic fitness but not to the same degree as adults, when following a similar training

programme.

No differences were observed between the two training groups in either aerobic or

anaerobic performance parameters. Differences were observed between the training a

control groups.

The training effects of each different program were not specific indicating that children

can be trained aerobically in a sprint (anaerobic) program. (Dykstra, G. L., Demetriou, D.

G., Copay, A. G., & Boileau, R. A. 1996).

Implication : The effects of specific training programs are general in children.

Any form of training trains all capacities in growing children.

51

10.1 Work Capasities In Children

Children typically demonstrate a higher ventilatory threshold (VAT), expressed as

%VO2max, than adults. This investigation found that the greater children's (M = 11; F =

10) values are best explained by lower levels of relative anaerobic capacity rather than

superior aerobic power ( Rowland, T., & Boyajian, A,1994)

Implication : The type of work at children's practices should be appropriately

programmed. A greater percentage of aerobic work, when compared to that which better

matches adults' capabilities, should be included.

52

CHAPTER 11

VO2max AND GROWTH

Research has consistently shown that relative VO2max (maximal aerobic power)

declines from the onset of adolescence. However, the use of mean VO2maxand mean age

may be misleading. The relationship is reported assuming that duration and distance in

the testing protocol are unimportant. The highest mean speed for a protocol is used to

determine VO2max at the point of perceived exhaustion ( Orban, W. A., & Kozak, J. F.

1997).

Males (N = 84) were studied for 10 years from the age of 7 through 16. It was found that

relating VO2maxto the specific variables of duration and distance a well as speed affects

the relationship between VO2max and age. A different understanding between age and

VO2max resulted.

1. VO2max, relative to performance, accelerates, rather than declines, through

adolescence.

53

2. To validly comprehend VO2max, it must be related to a specific maximal performance

of a given distance or duration under specific performance conditions.

Implication : The traditional use of VO2max produces a spurious understanding

for actual performance. Adolescents increase in aerobic performance for specific tasks as

age increases. Thus, it becomes important to talk of maximal aerobic power for what task

rather than just quoting a number as if there is a very simple entity of VO2max that exists

independent of task quality. Performance features must be included in any consideration

of aerobic capacity.

11.1 Growth, Puberty And Exercise

Puberty is characterized by the onset and continued development of secondary

sexual characteristics and an abrupt onset of linear growth. The secondary sexual

characteristics are a result of androgen production from the adrenals in both sexes

(adrenarche) and testosterone from the testes in the male and estrogens from the ovaries

in females (gonadarche).

During early childhood linear growth velocity declines rapidly to reach a constant

childhood rate of approximately 5.5 cm per year. With the onset and progression of

pubertal development, the rate accelerates markedly to reach a peak during mid-

adolescence (later in the developmental process in boys compared with girls) and then

diminishes toward zero as the bony epiphyses fuse. Pubertal growth spurt cannot occur

54

without sufficient quantities of growth hormone. hGH alone apparently is not sufficient,

since important physiological synergism exists between the gonadal axis and hGH

secretion coincident with the progression of puberty.

Shortly after cessation of linear growth, the circulating pattern of hGH returns to the

prepubertal configuration with the result that the hGH concentration versus time profiles

in young men are remarkably similar to those in prepubertal boys, but greater than those

in older men despite a continued rise in serum testosterone concentration. hGH secretion

(and other pituitary hormones) occurs in a repetitive, burst-like manner (Rogol, A. D.

1994).

The pubertal growth spurt is likely subserved by altered neurosecretory dynamics for

growth hormone. The augmented hGH secretion apparently results from an increase in

the maximum rate of hGH release rather than from an increase in hGH burst frequency

caused in the main by increasing amounts of circulating gonadal steroid hormones. The

markedly altered hormone levels subserve the equally profound changes in body

composition, regional fat distribution, and muscular strength. Gonadal steroid hormones

strongly regulate growth and hGH secretion at puberty. However, any straightforward

relationship between growth velocities and the circulating hGH concentrations, or

attributes of hGH neurosecretion, is diffused by the added components of hGH binding

proteins, circulating IGF-1 and its binding proteins, and the complex metabolic signals

that reflect the relative fatness of an individual, even when well within the physiological

range.

55

11.2 Exercise And Growth

The "anabolic effects" of exercise are defined as constructive or biosynthetic

metabolic processes involved in tissue adaptation to physical activity. A sizable anabolic

stimulus arises from the relatively modest physical activity of daily living. Excessive

training may have adverse effects (it has been reported that a reduction of growth

potential occurs in female gymnasts engaged in intense training).

Naturally occurring levels of physical activity, energy expenditure, and muscle strength

exhibit some of their most rapid increases during childhood and puberty. Most children

pass through activity phases that far exceed those of adults, and some biologically

essential, minimal threshold of activity is reached by the vast majority of healthy

children. The effects of exercise on somatic growth become important only if a child's

level of activity (possibly due to social, psychological, or disease causes) falls below this

biological threshold.

Exercise modulation of growth does not imply that increasing levels of physical activity

will increase somatic growth in healthy children. Increases in heart mass or skeletal

muscle mitochondrial density may have little impact on overall body size. Conflicting

results have been obtained from studies done to test the effect of training on growth rates

in children.

It may be useful to focus on exercise anabolic effects in terms of cardio respiratory

adaptation rather than somatic growth. There is evidence that an integrated cardio

respiratory and muscular response to exercise may be modulated by childhood patterns of

56

physical activity and exercise. The time to respond to the onset of exercise and to recover

is faster in children than in adults. These responses are also faster in lean children than

those who are obese. This suggests that CO2 transport from cells to the lungs is delayed

by the high solubility of CO2 in adipose tissue. This may also explain the differences in

CO2 transport dynamics between adults and children since adiposity increases with age

in adults. Children also work less efficiently in terms of oxygen cost of exercise than do

adults.

Patterns of physical activity during childhood may affect the incidence and morbidity of

disease later in life.

11.3 Peripheral mechanisms of exercise stimulation.

Energy generated by exercise is transformed into signals that stimulate cellular

anabolism at the site of the exercise. Physical stretch profoundly influences endothelial

cell orientation and actin cytoskeleton organization. In exercising muscle, PO2 and pH

are low and lactate concentrations are high. Similar conditions can be found in the

interior milieu of wounds. The healing wound is characterized by new capillary and

collagen formation which suggests that there is a parallel between wound healing and

exercise-induced anabolism (Cooper, D. M. 1994).

11.4 Central mechanisms.

57

Physical activity is a naturally occurring stimulator of growth hormone (hGH)

release into the circulation. hGH induces tissue production of IGF-1 (insulin-like growth

factor 1) and elevations in serum IGF-1. An hypothesis exists that exercise induced hGH

release is partly responsible--directly or indirectly--for anabolic effects of exercise. hGH

plays an important role in anabolic effects of exercise, but the mechanism of regulation is

not known. The role of the pattern of physical activity in the adult or developing child

may prove to be particularly important. hGH given in pulses results in more and better

growth than when it is given continuously. Thus, the body has a mechanism that pulses

hGH rather than continuously introducing it into the system. It is intriguing to note that

activity patterns in children are characterized by bursts of exercise, perhaps being a

pattern that optimizes the anabolic effects of exercise in the growing child.

Both hGH -dependent and hGH -independent pathways likely exist and link exercise with

tissue anabolism.

11.5 Nutritional factors.

One possible mechanism that affects exercise-stimulated hGH release is diet.

Glucose ingestion leads to hyperglycemia that inhibits hGH release. Meals high in fat

could inhibit pituitary hGH release either by the direct effect of free fatty acids on the

pituitary, or might cause release of gastric and pancreatic somatostatin. A single high-fat

meal prior to exercise can interfere with performance and prolong the period of recovery.

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11.6 Structure-function interactions.

The athlete's heart is more massive in both absolute and normalized to body

weight terms. The combination of a high-fat diet and inactivity contributes to the

development of obesity, hypercholesterolemia, hypertension, and coronary artery disease.

One could argue that there is no need in healthy children to attempt to impose patterns of

physical activity since the natural inclination of children is to be active (they maximize

the anabolic effects of exercise).

The use of growth promoting agents may have different long-term physiological

consequences in children compared with adults. Drug use touted to boost body height,

strength, and athletic prowess in normal children and young adults should be construed as

being abuse.

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CHAPTER 12

SPORT INJURIES IN CHILDREN

12.1 Reasons for Concern

Young athletes are not merely small adults. Their bones, muscles, tendons, and

ligaments are still growing, which makes them more susceptible to injury.

Growth plates - the areas of developing cartilage where bone growth occurs in youngsters

- are weaker than the nearby ligaments and tendons. What is often a bruise or sprain in an

adult can be a potentially serious growth plate injury in a young athlete. Young athletes

of the same age can differ greatly in size and physical maturity. Some youngsters may be

physically less mature than their peers and try to perform at levels for which they are not

ready.

Parents and athletic coaches should try to group youngsters according to skill level and

size, not chronological age, particularly during contact sports. If this is not practical, they

should modify the sport to accommodate the needs of children with varying skill levels.

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12.2 Types of Injuries

Injuries among young athletes fall into two basic categories: overuse injuries and

acute injuries. Both types include injuries to the soft tissues (muscles and ligaments) and

bones.

Acute injuries are caused by a sudden trauma. Common acute injuries among young

athletes include contusions (bruises), sprains (a partial or complete tear of a ligament),

strains (a partial or complete tear of a muscle or tendon) and fractures. But not all injuries

are caused by a single, sudden twist, fall, or collision. A series of small injuries to

immature bodies can cause minor fractures, minimal muscle tears, or progressive bone

deformities, known as overuse injuries.

As an example, "Little League Elbow" is the term used to describe a group of common

overuse injuries in young throwers involved in many sports, not just baseball. Other

common overuse injuries occur in the heels and knees with tears in the tissue where

tendons attach to the leg bone or the heel bone.

Contact sports have inherent dangers that put young athletes at special risk for severe

injuries. Even with rigorous training and proper safety equipment, youngsters are at risk

for severe injuries to the neck, spinal cord, and growth plates. However, following the

rules of the game and using proper equipment can decrease these risks.

12.2.1 Soft tissue injuries

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Fortunately major sports-related injuries are rare in young people. About 95% of

sports injuries are due to minor trauma involving soft tissues-bruises, muscle pulls,

sprains (ligaments), strains (muscles and tendons), and cuts or abrasions. Little sports

time is lost from these injuries. Moreover, sports injuries occur more frequently in

physical education classes and free-play sports than in organized team sports. Minimal

safety precautions and supervision can prevent many injuries.

12.2.2 Sprains

Almost one-third of all sports injuries are classified as sprains. A sprain is a

partial or complete tear of a ligament, which is a tough band of fibrous connective tissue

that connects the ends of bones and stabilizes the joint. Symptoms include the feeling that

a joint is "loose" or unstable; an inability to bear weight because of pain; loss of motion;

the sound or feeling of a "pop" or "snap" when the injury occurred, and swelling. Not all

sprains produce pain, however.

12.2.3 Strains

A strain is a partial or complete tear of a muscle or tendon. Muscle tissue is made

up of cells that contract and make the body move. A tendon consists of tough connective

tissue that attaches muscles to bones.

12.2.4 Contusions

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The most common sports injury contusions (bruises) rarely cause a student athlete

to be sidelined. Bruises result when a blunt injury causes underlying bleeding in a muscle

or other soft tissues.

Prompt treatment for soft tissue injuries usually consists of rest, applying ice, wrapping

with elastic bandages (compression), and elevating the injured arm, hand, leg or foot.

This usually limits discomfort and reduces healing time. Proper first aid will minimize

swelling and help the physician establish an accurate diagnosis.

12.2.5 Spinal cord injuries

Although spinal cord injuries in sports are rare, ten percent of all spinal injuries

occur during sports, primarily diving, surfing and football. They can range from a sprain

to paralysis in the arms and legs (quadriplegia) to death. Participants in contact sports can

minimize the risk of minor neck spinal injuries-sprains and pinched nerves-by doing

exercises to strengthen their neck muscles.

12.2.6 Skeletal injuries

A sudden, violent collision with another player, an accident with sports equipment

or a severe fall can cause skeletal injuries in the growing athlete, including fractures.

Fractures constitute a low five to six percent of all sports injuries. Most of these breaks

occur in the arms and legs. Rarely are the spine and skull fractured.

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More common, however, are stress fractures and ligament-bone disruptions that occur

because of continuing overuse of a joint. The main symptom of a stress fracture is pain.

Frequently, initial x-rays do not show any signs of a stress fracture so the athlete is

permitted to return to the same activity. Unfortunately the pain often returns or continues,

but the athlete keeps playing. The most frequent places stress fractures occur are the tibia

(the larger leg bone below the knee), fibula (the outer and thinner leg bone below the

knee), and foot.

"Little League elbow" can result when a pitcher's repetitive throwing puts too much

pressure on the elbow bone's growth centers. This painful condition results from over

usage of muscles and tendons or from an injury to the cartilage surfaces in the elbow.

In the growing athlete's musculoskeletal system, pain from repetitive motion may appear

somewhere besides the actual site of the injury. For instance, a knee ache in a child or

adolescent may actually be pain caused by an injury to the hip.

12.3 Diagnosis and treatment

Children and teens often experience some discomfort with athletic activity. Their

bones and muscles are growing, and their level of physical activity may increase with a

sudden, intense interest in sports, so some aches and pains can be expected. Still, their

complaints always deserve careful attention. Some injuries, if left untreated, can cause

permanent damage and interfere with proper physical growth.

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Whether an injury is acute or due to overuse, a child who develops a symptom that

persists or that affects his or her athletic performance should be examined by an

orthopedic surgeon. A child should never be allowed or expected to "work through the

pain."

Signs that warrant a visit to an orthopedic surgeon include:

Inability to play following an acute or sudden injury.

Decreased ability to play because of chronic or long-term complications following

an injury.

Visible deformity of the athlete's arms or legs.

Severe pain from acute injuries which prevent the use of an arm or leg.

Prompt treatment can often prevent a minor injury from becoming worse or causing

permanent damage.

During the evaluation, the orthopedic surgeon will inquire as to how the injury occurred

and will examine the child. If necessary, the doctor may perform X-rays or other tests, to

evaluate the bones and soft tissues.

The basic treatment for many simple injuries is often "R.I.C.E."-Rest Ice Compression

Elevation.

Treatment for a child with any significant injury will usually involve specific

recommendations for temporary or permanent adjustment in athletic activity. Depending

on the injury's severity, treatment may range from simple observation with minor changes

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in athletic level to a recommendation that the athletic activity be discontinued. Some

combination of physical therapy, strengthening exercises, and bracing may also be

prescribed.

A basic component of any treatment plan is the orthopedic surgeon's ongoing assessment

of the child's physical condition until signs of healing and reduction of symptoms occur.

Successful treatment requires cooperation and open communication among the patient,

parents, coaches, and doctors.

Diagnosis of any sports-related orthopedic injury should be made promptly by orthopedic

surgeons, physicians who specialize in the care of the musculoskeletal system. The

physician usually will ask the young athlete how the injury occurred, then follow with

questions about the type of pain-whether it is a stabbing pain, a dull ache or throbbing-the

location of the pain, and the sport in which the athlete was involved.

During the physical examination, the orthopedist will ask the athlete to move the affected

area to determine whether the child's motion has been affected. The orthopedist will

gently touch the area to observe for obvious skeletal abnormalities. X-rays or other

radiographic tests may be ordered, depending on the athlete's condition and the doctor's

need for additional information.

Orthopedic surgeons have been in the forefront of treating musculoskeletal system

injuries and have a long tradition of caring for young athletes. In the last two decades,

they have analyzed and clarified young athletes' psychological needs, conditioning,

training, and susceptibility to physical injury. They provide early and comprehensive care

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of orthopedic injuries. This can help young athletes heal and return to competition with

less chance of repeated injury. Treatment varies according to the patient's condition, but it

may include bed rest, elevation, compression bandages, crutches, cast immobilization or

physical therapy.

12.4 Female athletes

Female involvement in sports has increased tremendously at the high school

level-by 700% over the last 15 years. Although early studies indicated that female

athletes needed to train at lower levels of intensity than male athletes, it appears that this

was more a social than a physiological problem. Today's female athlete is able to train

and frequently compete at levels that rival many of the best male athletes. Although there

are differences in performance that are sex-related, athletic injuries are related more to

the player's sport than sex.

12.5 Risk and benefits

Sports activity by young people is generally safe with low risks and high benefits.

The major goal should be enjoyable participation. Exposure to competitive and

noncompetitive sports encourages the development of fitness, motor skills, social skills

and life-long appreciation for sports.

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Orthopedist is a medical doctor with extensive training in the diagnosis, and non-surgical

and surgical treatment of the musculoskeletal system, including bones, joints, ligaments,

tendons, muscles and nerves.

CHAPTER 13

GUIDELINES FOR PREVENTING SPORTS INJURIES

The American Academy of Orthopedic Surgeons, Pediatric Orthopedic Society of

North America, Canadian Orthopedic Association, and American Orthopedic Society for

Sports Medicine designed Play It Safe! to help parents, coaches, and children prevent

sports injuries. Play It Safe! Encourages children to:

Be in proper physical condition to play a sport.

Know and abide by the rules of the sport.

Wear appropriate protective gear (for example, shin guards for soccer, a hard-

shell helmet when facing a baseball pitcher, a helmet and body padding for ice

hockey).

Know how to use athletic equipment (for example, correctly adjusting the

bindings on snow skis).

Always warm up before playing.

Avoid playing when very tired or in pain.

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13.1 Play It Safe

Young athletes need proper training for sports. They should be encouraged to

train for the sport rather than expecting the sport itself to get them into shape.

Many injuries can be prevented if youths follow a regular conditioning program

with incorporated exercises designed specifically for their chosen sport. A well-

structured, closely supervised weight-training regimen may modestly help

youngsters prepare for athletic activities. Young athletes should have their

coaches help them design a conditioning program suited to their needs.

Parents should make sure their child's coaches have the appropriate qualifications

to supervise a particular sport, provide well-maintained safety equipment, and

help with proper conditioning for that sport.

An estimated 500,000 young athletes, boys and girls, use black-market anabolic

steroids to improve their athletic performance. Steroids have been shown to

increase muscle mass, but they can cause serious and potentially life-threatening

complications and should be avoided.

Youth sports should always be fun. The "win at all costs" attitude of many

parents, coaches, professional athletes, and peers can lead to injuries. A young

athlete striving to meet the unrealistic expectations of others may ignore the

warning signs of injury and continue to play with pain.

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Coaches and parents can prevent injuries by fostering an atmosphere of healthy

competition that emphasizes self-reliance, confidence, cooperation, and a positive

self-image, rather than just winning.

Youths, coaches, and parents should Play It Safe!

Your orthopedist is a medical doctor with extensive training in the diagnosis and non-

surgical and surgical treatment of the musculoskeletal system, including bones, joints,

ligaments, tendons, muscles, and nerves.

CHAPTER 14

EVERCISES FOR YOUNG ATHLETES

Staying injury-free throughout the sports season requires a proper conditioning

and exercise program. Here are some stretching exercises developed by the American

Academy of Orthopedic Surgeons that young athletes can perform before participating in

any athletic activity.

Athletes must do each one of the exercises carefully, speed is not important. Once the

exercise routine is learned, the entire program should take no longer than 10 minutes.

It also is important to warm up before doing any of these exercises. Good examples of

warm up activities are slowly running in place and walking for a few minutes.

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Seat Straddle Lotus

Sit down; place soles of feet together and drop knees toward floor. Placeforearms on inside of knees and push knees to the ground. Lean forward,bringing chin to feet. Hold for five seconds. Repeat three to six times.

Seat Side Straddle

Sit with legs spread; place both hands on same ankle. Bring chin to knee,keeping the leg straight. Hold for five seconds. Repeat three to six times.Repeat exercise on opposite leg.

Seat Stretch

Sit with legs together, feet flexed, hands on ankles. Bring chin to knees.Hold for five seconds. Repeat three to six times.

Lying, Quad Stretch

Lie on back with one leg straight, the other leg with hip turned in andknee bent. Press knee to floor. Hold for five seconds.Repeat three to six times.

Knees to Chest

Lie on back with knees bent. Grasp tops of knees and bring them out towardthe armpits, rocking gently. Hold for five seconds. Repeat three to five times.

Forward Lunges

Kneel on left leg; place right leg forward at a right angle. Lunge forward,keeping the back straight. Stretch should be felt on the left groin. Holdfor five seconds. Repeat three to six times. Repeat on opposite leg.

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Side Lunges

Stand with legs apart; bend the left knee while leaning toward the left.Keep the back straight and the right leg straight. Hold for five seconds.Repeat three to six times. Repeat on opposite leg.

Cross-Over

Stand with legs crossed; keep feet close together and legs straight. Touchtoes. Hold for five seconds. Repeat three to six times.Repeat with opposite leg.

Standing Quad Stretch

Stand supported. Pull foot to buttocks. Hold for five seconds.Repeat three to six times.

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CHAPTER 15

NUTRITION FOR YOUNG ATHLETES

Proper nutrition is critical for both good health and optimal sports performance.

For child athletes, an adequate diet is critical because nutritional needs are increased by

both training and the growth process. Young athletes and their parents are frequently

unaware of the appropriate components of a training diet. The following 4 areas are of

particular concern.

15.1 Total Caloric Intake

Athletic training creates a need for increased caloric intake, and requirements

relative to body size are higher in growing children and adolescents than at any other

time in life. In child athletes, the energy intake must be increased beyond the needs of

training to maintain adequate growth. Children who engage in sports in which

slenderness is considered important for optimizing performance (i.e., gymnastics, and

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ballet dancing) may be at risk for compromising their growth. A risk for pathologic

eating behaviors also may be increased in children participating in sports where leanness

is rewarded.

15.2 Balanced Diet

Balance, moderation, and a variety of food choices should be promoted. The Food

Guide Pyramid can be used to plan a diet that is balanced and provides sufficient

nutrients and calories for both growth and training needs. Athletes who focus on

particular dietary constituents (such as carbohydrates) at the expense of a well-rounded

diet may potentially compromise their performance as well as their health.

15.3 Iron

The body's requirement for iron is greater during the growing years than at any

other time in life. Adequate iron stores are important to the athlete to provide adequate

oxygen transport (hemoglobin), muscle aerobic metabolism (Krebs' cycle enzymes), and

cognitive function. However, athletes often avoid eating red meat and other iron-

containing foods. Moreover, sports training itself may increase body iron losses.

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15.4 Calcium

Inadequate calcium intake is common in athletes, presumably because of their

concern about the fat content in dairy foods. Normal bone growth, and possibly,

prevention and healing of stress fractures, are contingent on sufficient dietary calcium.

CHAPTER 16

SEXUAL MATURATION

Athletic girls tends to experience menarche at a later age than non-athletic girls,

leading to concern that intensive sports training might delay sexual maturation. The

average age of menarche in healthy North American girls is 12.3 to 12.8 years, while that

of athletes in a wide variety of sports is typically 1 to 2 years later. Under nutrition,

training stress, and low levels of body fat have been hypothesized to account for this

delay. Alternatively, it is possible that the later age of menarche in athletes simply

reflects a pre-selection phenomenon. Girls who have narrow hips, slender physiques, long

legs, and low levels of body fat—advantageous characteristics in many girls' sports—are

more likely to experience later menarche regardless of sports participation.

Secondary amenorrhea, or cessation of menstrual cycles after menarche, can occur as a

result of intense athletic training. Prolonged amenorrhea may cause diminished bone

mass from the associated decrease in estrogen secretion, augmenting the risk for stress

fractures and the potential for osteoporosis in adulthood. Efforts to improve nutrition or

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diminish training volume in these girls may permit resumption of menses and diminish

these risks.

Studies of males have indicated no evidence of an adverse effect on sexual maturation

related to sports training. Progression of Tanner stages of pubertal development has not

been observed to be retarded in athletic compared with non-athletic adolescents.

CHAPTER 17

PSYCHOSOCIAL DEVELOPMENT

Considerable research has addressed anxiety and stress that affect children who

engage in competitive sports but little data exist about the effects of more intense or

sustained training on young athletes. Anecdotal reports suggest risks of "burnout" from

physical and emotional stress, missed social and educational opportunities, and

disruptions of family life. Unrealistic parental expectations and/or exploitation of young

athletes for extrinsic gain can contribute to negative psychological consequences for elite

young athletes. Survey studies suggest, however, that while such adverse effects occur,

they are experienced by only a small minority of intensely training athletes. Most athletes

find elite-level competition to be a positive experience.

Research supports the recommendation that child athletes avoid early sports

specialization. Those who participate in a variety of sports and specialize only after

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reaching the age of puberty tend to be more consistent performers, have fewer injuries,

and adhere to sports play longer than those who specialize early.

17.1 HEAT STRESS

Child athletes differ from adults in their thermoregulatory responses to exercise in the

heat. They sweat less, create more heat per body mass, and acclimatize slower to warm

environments. As a result, child athletes may be more at risk for heat-related injuries in

hot, humid conditions. It is particularly critical that coaches, parents, and young athletes

are aware of signs of heat injury. They also should be aware that limiting sports play and

training in hot, humid conditions and ensuring adequate fluid intake can prevent heat

injury.

RECOMMENDATIONS

Although many concerns surround intense sports competition in children, little

scientific information is available to support or refute these risks. Nonetheless, it is

important to make efforts to assist young athletes in avoiding potential risks from early

77

excessive training and competition. The following guidelines are suggested keeping in

mind 1) the importance of assuring safe and healthy sports play for children, 2) the need

to provide practical and realistic guidelines, and 3) the limited research basis for making

such recommendations.

1. Children are encouraged to participate in sports at a level consistent with their

abilities and interests. Pushing children beyond these limits is discouraged as is

specialization in a single sport before adolescence.

2. Pediatricians should work with parents to ensure that the child athlete is being

coached by persons who are knowledgeable about proper training techniques,

equipment, and the unique physical, physiologic, and emotional characteristics of

young competitors.

3. In the absence of prospective markers of excessive physical stress, physicians and

coaches should strive for early recognition and prevention and treatment of

overuse injuries (tendinitis, apophysitis, stress fractures, "shin splints"). Child

athletes should never be encouraged to "work through" such injuries. Treatment

recommendations for overuse injuries that include only "rest" or cessation of the

sport are unlikely to be followed by the committed child athlete and are unlikely

to adequately address the risk of further injury.

4. The conditions of child athletes involved in intense training should be monitored

regularly by a pediatrician. Attention should be focused on serial measurements of

body composition, weight, and stature; cardiovascular findings; sexual

maturation; and evidence of emotional stress. The pediatrician should be alert for

78

signs and symptoms of overtraining, including decline in performance, weight

loss, anorexia, and sleep disturbances.

5. The intensely trained, specialized child athlete needs ongoing assessment of

nutritional intake, with particular attention to total calories, a balanced diet, and

intake of iron and calcium. Serial measurements of body weight are particularly

important in ensuring the adequacy of caloric intake and early identification of

pathologic eating behaviors.

6. The child athlete, family, and coach should be educated by the pediatrician about

the risks of heat injury and strategies for prevention.

In summary, the following guidelines should be followed when training prepubescent

athletes in the sport of weightlifting:

1. The training of young athletes should emphasize the development of general physical

qualities and not overemphasize weightlifting.

2. Training should be limited in volume and intensity. (Beginners neither require nor

benefit from excessive loading, and in children the risks of such loading make it even

more important that moderation be stressed.)

3. The training load should be only gradually increased, and the increase should be

cyclical in nature, so that there is an overall increase but high and low loads are

interspersed throughout the training process.

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Athletes should be carefully evaluated and monitored to identify those at increased risk

for injury or those who have any negative reaction to training (e.g., delayed menarche).

The biological, psychological and emotional age should be considered along with the

chronological age in planning the training. In sports which have a relatively high

incidence of certain kinds of injuries, athletes should be monitored and examined

frequently to assure that no injury is being incurred. This is particularly important for

those who have a physical characteristic which places them at increased risk. Careful

instruction in technique and modification for individual needs are required in order to

develop skills that are both safe and efficient for that athlete.

When training young athletes, the emphasis should be on the development of a love for

the sport and for training. Such a foundation will carry a lifter much further than any

physical capabilities that are developed through early training.

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Bill of Rights For Young Athletes 

The Bill of rights for young athletes was developed in the 1980's by Dr. Vern

Seefeldt, professor emeritus at the Institute for the Study of Youth Sports, and Dr. Rainier

Martens, in response to growing concerns regarding the abuse of young athletes.  This

bill has been used by a number of national organizations as a guideline for coaches and

parents.  Feel free to use this bill as a guide for the coaches and parents in your

organization.  However, please recognize the authors and the Institute for the Study of

Youth Sports as its source

 

1. Right to participate in sports

2. Right to participate at a level commensurate with each child's maturity and ability

3. Right to have qualified adult leadership.

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4. Right to play as a child and not as an adult

5. Right of children to share in the leadership and decision-making of their sport

participation

6. Right to participate in safe and healthy environments

7. Right to proper preparation for participation in sports

8. Right to an equal opportunity to strive for success

9. Right to be treated with dignity

10. Right to have fun in sports

Reprinted with permission from Guidelines for Children's Sports, R. Martens and V.

Seefeldt (Eds.)., Washington, D.C. American Alliance for Health, Physical Education,

Recreation and Dance, 1979.

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