chapter four: becoming physically fit. basic concepts physical fitness a set of attributes that...
Post on 28-Dec-2015
217 Views
Preview:
TRANSCRIPT
Basic Concepts
Physical fitnessA set of attributes that people have or achieve
that relates to the ability to perform physical activity
Physical activityAny bodily movement produced by skeletal
muscles that results in energy expenditureExercise (subset of physical activity)
Planned, structured, and repetitive activity designed to improve or maintain physical fitness
Four Components of Physical Fitness
1. Cardiorespiratory endurance Aerobic vs. anaerobic exercise
2. Muscular fitness Strength vs. endurance
3. Flexibility
4. Body composition
Cardiorespiratory Endurance
Ability of the heart, lungs, and blood vessels to process and transport oxygen over a period of time
Produced by exercise involving continuous, repetitive movementsExamples: brisk walking, jogging, cycling
Aerobic (with oxygen) energy productionStructural and functional benefits
Muscular Fitness
Strength: Ability to contract skeletal muscles to a maximal level
Endurance: Ability to contract skeletal muscles repeatedly over a long period of time
Improved by performing repeated contractions at less than maximal levels
Flexibility and Body Composition
Flexibility: Ability of your joints to move through an intended range of motion
Body composition: The make-up of the body in terms of muscle, bone, fat, water, and minerals Fitness experts are most concerned with
percentages of body fat and fat-free weight
Developing a Personalized Fitness Program: Key Principles
• Overload: Placing increasing amounts of stress or resistance on the body causes changes that improve fitness
• Specificity: The type of exercise must be specific to the outcome that is targeted for improvement
• Reversibility (regression): “Use it or lose it”
Physiology
Non-use of muscles leads to quick atrophy
Overuse of muscles leads to lactic acid build up
Chronic overuse leads to oversize issues with muscles and heart
Developing a Cardiorespiratory Endurance Program
1. Mode of activity Continuous activity Using large muscle groups Aerobic in nature Enjoyable Cross-train and/or vary activities to maintain
motivation
Developing a Cardiorespiratory Program
2. Frequency (How often should I train?) 3-5 times/week More than 5 times/week will not create further
improvement Less than 3 times/week will not show significant
improvement
Developing a Cardiorespiratory Program
3. Intensity (How hard should I train?) Target heart rate (THR) = Between 65% and
90% of maximum heart rate Maximum heart rate can be estimated by
subtracting your age from 220
Target heart rate range = (220 – age) x 65-90% Sample calculation for a 20-year-old:
220 - 20 = 200 x 0.65 = 130 bpm
220 - 20 = 200 x 0.90 = 180 bpm
Developing a Cardiorespiratory Program
4. Duration• ACSM recommends 20-60 minutes of
continuous activity• The lower the intensity, the longer the
duration should be
Muscular Fitness
Types of Muscular Fitness Exercises Isometric (“same length”): Muscle contraction
without movement Isotonic (“same tension”): Muscle contraction with
movement against a specific fixed resistance throughout the full range of motion
Isokinetic (“same motion”): Muscle contraction with movement against variable resistance through the full range of motion at a fixed speed
Muscular Fitness
Frequency: 2 times/weekOne set of 8-12 repetitions (10-15 repetitions for
adults over 50) of 8-10 exercises Multiple sets could provide greater benefits
Sufficient resistance to fatigue major muscle groups (legs, arms, shoulders, chest, back)
Training recommendations Isotonic or isokinetic exercises Full range of motion at a slow to moderate speed using
rhythmic breathing
Flexibility
Failure to maintain flexibility can result in reduced range of motion and injury
Two forms of stretching motions: Static stretching: Slow lengthening of a muscle
group to an extended stretch, followed by a hold of the extended position for 10-30 seconds Recommended
Ballistic stretching: A bouncing form of stretching in which a muscle group is lengthened repetitively to produce multiple quick, forceful stretches
Flexibility Training
Stretch all major muscle groups2-3 times/weekShould be done following a warm-upStatic stretching is preferred over ballistic
stretchingHold each stretch for 10-30 seconds
Body Composition
Measurement of percent body fat is often included in a fitness program
To reduce body fat, an exercise program should maximize caloric expenditure ACSM recommends exercise sessions expending
300-400 calories
The Workout Routine
Warm-up (5-10 minutes of slow, gradual, comfortable movements related to the upcoming activity; can end with a period of stretching)
Conditioning (cardiorespiratory endurance, strength training, and/or flexibility workout following ACSM guidelines)
Cooldown (5-10 minutes of relaxing exercises to return the body to a resting state)
Exercise Over the Life Span: Children
Research and recommendations for children’s physical activityU.S. children and teenagers lead very sedentary
livesIncreased percentage of children and teenagers
are overweightNeed at least 60 minutes every day of moderate-
intensity physical activity
Exercise and Aging
Change is gradualIndividual differences occurGreatest change is noted in
areas of complex functionHomeostatic decline occurs
with ageStay physically active to slow
physical decline
Changes in Midlife Adults
Period between 45 and 64 years of age Decrease in bone mass and density Increase in vertebral compression Degenerative changes in joint cartilage Increase in body fat Decrease in capacity to engage in physical work Decrease in visual acuity Decrease in resting energy requirements Decrease in fertility Decrease in sexual function
Changes in Older Adults
Decrease in bone mass and changes in bone structure
Decrease in muscle bulk and strengthDecrease in cardiorespiratory enduranceLoss of nerve cellsDecrease hearing and vision abilitiesDecrease in sensory modalitiesSlower reaction timeGait and postural changes
Exercise for Older Adults
Exercises for younger adults may be inappropriate for people over aged 50
Supervision from a certified instructor may be necessary
Physical exams are recommended before beginning a program
Well-designed programs should start slowly Recognize signs of distress
Special Health Concerns
Low-back painAffects 4 out of 5 adults at least once in their
lifetimesMechanical (postural) problems tend to be the
main culpritRegular physical activity greatly reduces the
occurrences of low-back pain
Special Health Concerns
Female athlete triad
Disordered eating, amenorrhea, and osteoporosis
Signs include: reduced cognitive function, altered hormone levels, early onset of menopause
Early physician referral is vital
Pregnancy Exercise should be
continued barring complications
Avoid overheating, impact exercises, and excessive bouncing or jarring motions
Special Health Concerns
Osteoporosis Decreased bone mass;
may lead to fractures 80% of suffers are
women Lower level of estrogen
may decrease calcium absorption
Adequate calcium and vitamin D intake; weight bearing exercise
Osteoarthritis Joint inflammation Common in older adults Often occurs in weight-
bearing joints Genetic predisposition is
also a key factor Regular physical activity
may reduce the risk for osteoarthritis
Training Recommendations
Drink enough fluid before, during, and after activity
Wear comfortable clothing that promotes temperature regulation
Use appropriate safety equipment
Exercise Injuries: Strategies for Prevention and Care
1. Start at a low level and progress gradually
2. If you stop exercising for an extended time, do not restart at the level at which you stopped
3. Listen to your body
4. Follow rehabilitation instructions carefully
5. Develop a preventive approach to all injuries
top related