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 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 VO 2max or VO 2 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 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% VO 2max 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 % 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 ~ 60 lb fat increase Do not “un-multiply”

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 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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