Exercise Prescriptions for Health and Fitness

Chapter 16

Physical Activity

Any form of muscular movement– Related to physical fitness

Exercise – A subset of physical activity for the purpose of

maintaining or improving physical fitness Can reduce the risk of death from all causes Physical inactivity is a primary risk factor for

coronary heart disease

The Dose-Response Relationship of Drugs

Dose-Response Relationship of Drugs (an example)

The effect (response) of the amount of a drug (dose)– Potency – how much an amount can effect– Slope – change in effect from change in dose– Maximal effect – the most it can do– Variability – different for different people– Side effect – other unwanted action

The Dose-Response Relationship for Exercise

@ 60-70% of max capacity

The Dose-Response Relationship for Physical Activity

The Exercise Dose – F.I.T.

Frequency– Number of days per week– Number of times per day

Intensity– Percent VO2max or VO2 reserve

– Percent maximal HR or heart rate reserve– Rating of perceived exertion– Lactate threshold

Time (duration)– Number of minutes of exercise– Total kcals expended – Total kcals per kg body mass

The Response to Exercise

Improving fitness– Thereby improving health

Improving fitness and health– Simultaneously or separately

Improving fitness– But not a specific health outcome

Improving a specific health outcome– But not improving fitness

Patterns in the Response to Exercise

Acute responses– Occur within one or several exercise bouts

but does not improve further Rapid responses

– Benefits occur early and plateau Linear

– Gains are made continuously over time Delayed

– Occurs only after weeks of training

Physical Activity and Health

The benefits of physical activity may be more related to total number of calories expended than exercise intensity

The “Exercise Lite” recommendation

“Every U.S. adult should accumulate thirty minutes or more of moderate-intensity

(3-6 METs) physical activity on most, preferably all, days of the week.”

Benefits of Improving Fitness

In previously sedentary subjects– Small changes in physical activity result in

large health benefits with minimal risk– Strenuous exercise

Increases the risk of a heart attack during activity– Reduces overall risk (rest + exercise)

Moderate to high levels of fitness– Reduce the risk of death from all causes

General Guidelines for Improving Fitness Screening

– Health status screening (PAR-Q) Progression

– Start with low-intensity exercise (walking)– Then increase duration and/or intensity

Warm-up, cool-down, and flexibility– Light exercise and flexibility performed at

beginning and end of exercise session

Exercise Prescription for Cardiorespiratory Fitness 200-300 kcals per session Considerations

– Weight loss– Improved fitness– Injury prevention

Frequency Intensity Time (duration)

Optimal Training Intensity, Duration, and Frequency

Exercise Intensity

Corresponding to 60-80% VO2max

Target heart rate (THR) range– Direct method

• HR at percentage of maximal work rate found during GXT

– Indirect method• 70-85% of maximal HR• 60-80% of HR reserve (Karvonen) method

.

Target Heart Rate Range Determined From GXT

Sequence of Physical Activity

Walking– Start at a comfortable speed for 15 minutes– Gradually increase duration and speed

Jogging– Start by adding some running when walking– Gradually increase speed/duration of running

Games and sports– Intermittent higher-intensity activities within THR

range

Strength Training

Muscular strength is an important component of physical fitness– Strength to do

everyday tasks– Strength for

“extraordinary” tasks

Strength Training

Recommendations (health-related)– Dynamic resistance exercises– Full range of motion– 8-10 different exercises– 8-12 repetitions per exercise– Weight that corresponds to 60 - 85% of 1RM– Large muscle groups first– Alternate muscle groups for rest– Progress with success

Flexibility

Normal joint Range of Motion (ROM)– Limited by bony structures– Limited by connective tissue– Limited by muscle tension

• “Re-set” tension / length

– Hyper mobility

Flexibility

Training to improve– Principles of exercise apply (O, S, R)– Corollary applies too (consistency)– Training variables apply (F, I, T)– Best done when muscles are “warm”– Best done - not to the point of pain– Best done slowly – static not ballistic

Body Composition

What makes up the body?– Water

• 99 out of every 100 molecules– Bone

• Skeletal, teeth– Protein

• Membranes, organs, muscle– Fat

• Membranes• Nervous tissue• Pericardial• Intramuscular• Intra-abdominal• Subcutaneous

Body Composition

Body fat– Stored carbons

Adipose cells– Increase volume to store carbons– Multiply when they reach a particular size

• @ ~ 60 lb fat increase• Do not “un-multiply”

Body Composition

Body Composition

Estimation vs. Measurement– Hydrostatic weighing– Skin fold calipers– Electrical impedance– Infrared absorbance– Dual X-ray Absorbtometry (DEXA)

Body Composition

Energy Consumption vs. Energy Expenditure– Handout

Body Composition 144,000 bariatric surgeries expected in 2004—up from 16,200 in 1992 Severely obese are increasingly turning to this life-altering measure. Most lose weight quickly and continue to lose for up to two years. Also seeing improvements in almost all their obesity-related conditions. 1 in 100 who have gastric bypass dies 10 - 20 percent of all bariatric surgery patients require follow-up operations

to correct complications. Almost 30 percent develop nutritional deficiencies, including osteoporosis,

anemia, and metabolic bone disease.  —Cate Lineberry - National Geographic

Remember……..

URWATU8

Questions?

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