Health Benefits of Physical Activity Chapter 9

Learning Objectives Be familiar with the health benefits of physical activity for children, adolescents, and adults as identified by the U.S. Dept. of Health and Human Services. Know the relationships among physical activity, fitness, and all-cause mortality. Be able to describe the relationships between body weight and the likelihood of developing various diseases. Understand the associations among physical activity and various degenerative diseases.

Our Unhealthy Lifestyle Choices We participate in work and leisure activities that are far less active than in the past. We produce and eat more food than we need. We control our environment with very little expenditure of physical energy. We subject ourselves to more and unusual stressors.

Your Perspective Automobiles, dishwashers, remote controls, and other technological devices have become indispensable parts of our lives. Would you ever give up some devices in order to increase your level of activity? Why or why not?

Health Benefits of Physical Activity for Children and Adolescents Increased cardiorespiratory fitness Increased muscular fitness Improved bone health Favorable changes in body composition Improved mood and mental health

Health Benefits of Physical Activity for Adults Reduced risk of premature death Reduced risk of cardiovascular risk factors and diseases Potential for reduced risk of some forms of cancer Improved bone health Increased muscular fitness Improved mood and mental health Enhanced weight management

Physical Activity, Fitness, and Mortality The more active you are, the less likely you are to die prematurely. Benefits of regular physical activity can be seen at all ages, with both genders. A modest increase in physical activity can have a substantial benefit, especially in sedentary individuals. Improvements in cardiorespiratory fitness, from low to moderately fit, are approximately the same as stopping smoking.

Relationship Between Physical Activity/ Cardiorespiratory Fitness and Mortality

Fitness and Cardiovascular Diseases Cardiovascular diseases are the number- one cause of death in the western world  Account for more than 40% of deaths in the United States. Physical activity decreases the risk of developing cardiovascular diseases.

Physical Activity, Physical Fitness, and Risk of Cardiovascular Diseases

Physical Activity and Coronary Heart Disease (CHD) CHD often manifests itself as a heart attack (myocardial infarction), atherosclerosis, or angina pectoris. Physical activity (e.g., aerobic exercise) reduces the risk for CHD:  Less likely to be obese or to develop diabetes mellitus  More likely to improve blood lipid profiles and increase high-density lipoprotein (HDL; “good” cholesterol)

Physical Activity and Stroke Physical activity may reduce the risk of stroke by slowing development of atherosclerosis and reducing hypertension. An individual who has had a stroke may need to begin an exercise program at a reduced intensity—then gradually increase exercise duration/intensity.

Physical Activity and Hypertension Physical activity is inversely related to blood pressure and risk of later development of hypertension. Aerobic exercise training is more effective than resistance training, but subjects should supplement exercise with resistance exercise.

Physical Activity and Peripheral Vascular Disease Peripheral vascular disease is similar to CHD (but in lower extremities). Risk factors:  Hyperlipidemia, smoking, hypertension, diabetes mellitus Regular aerobic exercise can reduce symptoms:  Walking and jogging are exercises of choice.

Physical Activity and Metabolic Syndrome Metabolic syndrome includes several cardiovascular disease risk factors:  Obesity, increased triglycerides, reduced HDL levels, increased blood pressure, increased fasting glucose levels. Individuals should gradually increase physical activity levels to 50–60 minutes 5 days a week (or more to promote weight loss).

Body Weight and Health Relationship between body weight and mortality is disease specific. Professionals who counsel individuals regarding body weight goals need to take into account mortality risks of different diseases.

Ratio of Actual to Predicted Mortality with Respect to BMI for Causes of Death

Obesity Prevalence is increasing in both genders and all ethnic groups. A risk factor for CHD. Contributing factors—physical inactivity and sedentary lifestyle Americans take in more calories than they expend.

Classifications of Obesity Hypertrophic (adult- onset) obesity :  A normal number of fat cells, which are twice as large as those of a non-obese person. Hyperplastic (juvenile-onset) obesity:  A higher number of enlarged fat cells.

Approximate Caloric Expenditure from Common Activities and Sports

Physical Activity and Weight Loss Calories are expended during physical activity. Additional calories are expended after exercise. Physical activity helps to maintain basal metabolic rate (BMR), whereas caloric restriction alone usually results in a decrease in BMR. Moderate exercise does not increase and may decrease appetite. Spot reducing does not work.

General Recommendations for Weight Management Provide a caloric intake not lower than approx. 1,200 kilocalories a day for typical adults Include foods that are acceptable to the dieter Provide a negative caloric balance that results in gradual weight loss (1 kg per week) Include guidelines for individuals who are overweight/obese (minimum loss of 5–10%) Include behavior modification techniques Combine caloric restriction and physical activity

Physical Activity and Cancer No consensus on whether there is a direct cause- and-effect relationship between physical activity and cancer prevention. However:  Level of physical activity is inversely related to the risk of developing colon cancer.  Activity patterns during adolescence and early adulthood may influence the risk of developing certain cancers. Exercise can help cancer patients combat ailments and side effects associated with cancer treatment.

Physical Activity and Diabetes Mellitus Type 1: Deficiency of the hormone insulin in circulation.  Exercise may increase insulin sensitivity. Type 2: Insulin does not normalize blood glucose levels, or insulin secretion from the pancreas is impaired.  Regular exercise improves insulin sensitivity and glucose tolerance.

Physical Activity and Osteoporosis Physical activity:  Aids in the development of bone mass and density during adolescence/young adulthood  Helps to maintain bone mass and density during middle age  Supplements estrogen therapy on the retention and development of bone density in post- menopausal women Weight-bearing aerobic activities plus resistance exercise

Exercise Programs for Post-Menopausal Women The wrong type of exercise can do more harm than good. Weight training can improve bone density while increasing muscular strength and balance. Adequate calcium intake is essential. Exercise is not a substitute for estrogen replacement therapy, when prescribed.

Physical Activity and Mental Health Physically active people are less likely to suffer from mood disturbances and anxiety disorders. Other effects of physical activity:  More positive outlook  Greater self-esteem  Enhanced ability to respond to stressors  Reduced symptoms of depression  Positive effects on trait and state anxiety

Your Perspective Your father’s father suffered several heart attacks before he passed away, and your mother’s mother broke her hip and suffered from depression. Your own parents know they should exercise more but aren’t sure what to do or how often. How do you counsel them about their exercise routine?

Where to Learn More Physical activity and health—women:  Physical activity, obesity, and weight control:  physical.htm physical.htm  National Osteoporosis Foundation: 

ACSM Certified Health Fitness Specialist Guidelines—1.2.7 Knowledge of the atherosclerotic process, the factors involved in its genesis and progression, and the potential role of exercise in treatment.  Imagine you are talking to your uncle, who works long hours and drives 90 minutes each way to/from his office. He knows he has various risk factors for heart disease but says he doesn’t have time to exercise.  What do you tell him?

ACSM CHFS Guidelines— and Knowledge of the effects of diet, exercise, behavior modification as methods for modifying body composition. Knowledge of the importance of an adequate daily energy intake for healthy weight management.  What would you advise someone who insists that he is healthy, but he seems to eat nothing but junk food?  What would you advise someone who says she never gains weight despite that fact that she never exercises?