Exercise Physiology & Fitness

1. Exercise Physiology & Fitness Chapter 7

2. Exercise Physiology & Fitness • What is exercise physiology? • What is the role of physical activity and exercise in achieving physical fitness and health? • How do you use the FITT formula to design a fitness program? • What are the contributors and deterrents to fitness?

3. Exercise Physiology • The study of the effects of exercise on the body. • Body’s responses and adaptations to different exercises: • System to subcellular level • Acute (short term) to chronic (long term) adaptations • Population served: • Elite performer • People of all ages and abilities

4. Historical Development • Late 1800s - the use of anthropometry to measure changes in students’ development after training programs. • Early 1900s – McKenzie ~ Investigating effects of exercise on various systems of the body and the idea of preventative medicine. • After WWII - increased interest in fitness as a result of youth fitness tests and the results of the physicals of men in the military. • 1968 – Dr. Kenneth H. Cooper promotes aerobic exercise and its contribution to health; publishes Aerobics.

5. Historical Development • 1974: ACSM: Guidelines for Graded Exercise Testing and Prescription. • 1980s and 1990s: Increased understanding of the relationship between physical activity and health. • 1996:Surgeon General’s Report Physical Activity & Health • 2000: 1st certification exams for Clinical Exercise Physiologists.

6. Areas of Study • Effects of various exercises on various systems of the body. • Relationship of energy metabolism to performance. • Effects of environmental factors on performance. • Effects of individual differences • Effectiveness of various rehabilitation programs. • Ergogenic aids and exercise. • Health and therapeutic effects associated with exercise. • Effects of nutrition on performance.

7. Specialization

8. Physical Fitness • Ability of the body’s systems to function efficiently and effectively. • Individuals who are “physically fit” have the ability to: • “carry out daily tasks with vigor and alertness, without undue fatigue, and with ample energy to enjoy leisure-time pursuits and to meet unforeseen emergencies.”

9. Physical Fitness Health Fitness • Body composition • Cardiorespiratory endurance • Flexibility • Muscular endurance • Muscular strength Performance Fitness • Agility • Balance • Coordination • Speed • Reaction Time • Power

10. Physical Activity and Health • Chronic Diseases • Major threat to health today • Hypokinetic Diseases • Diseases caused by insufficient physical activity, often in conjunction with inappropriate dietary practices. • Coronary heart disease, hypertension, osteoporosis, non-insulin diabetes, chronic back pain, and obesity

11. Physical Inactivity & Health • Inactivity is a risk factor for several diseases. • Individuals who lead a sedentary lifestyle have increased risk of morbidity and mortality. • Inactive individuals have almost twice the risk of CHD as those who are active. • The degree of risk is similar to cigarette smoking, hypertension, and obesity.

12. Dose-response Debate • What kind of activity? • How much time spent in activity? • At what intensity should it be performed? • How often in order to see benefits?

13. Consensus Statement • Recommended that adults engage in 150 minutes of moderate-intensity or 75 minutes of vigorous-intensity physical activity per week. • Recommended that adults engage in muscle-strengthening exercises on 2 or more days a week that work all the major muscle groups. Additional benefits can be derived from increasing the amount and/or intensity of physial activity.

14. Health Benefits • Enhanced cardiovascular function, including reduction of many cardiovascular disease risk factors. • Increased ability to perform tasks of daily living. • Reduced risk of muscle and joint injury. • Improved work performance. • Improved physical appearance, self-image, and sound mental health. • Reduction of susceptibility to depression and anxiety

15. Health Benefits • Management of stress. • Increased socialization through participation in physical activities. • Improved overall general motor performance. • Increased energy. • Resistance to fatigue. • Mitigate the debilitating effects of old-age or retain a more desirable level of health for a longer period of time.

16. Energy Production for PA • Two ways to produce ATP (adenosine triphosphate) as energy to perform muscular activity: • Anaerobic system • Without oxygen • High energy expenditure, short time (6-60 seconds) • Aerobic system • With oxygen • Lower rate of energy expenditure, longer period of time (more than 3 minutes)

17. Principles of Fitness Training • Principle of Overload • To gain improvements in health and fitness, an increased workload must be placed on the body. • Principle of Specificity • Training must occur with the specific muscle or body part the person is attempting to improve. • Principle of Progression • Overload should be applied gradually, and steadily increased as the body adapts. • Principle of Diminishing Returns • As fitness increases, gains achieved become less and less as individuals approach limits of adaptability.

18. Principles of Fitness Training • Principle of Variation • Helps maintain individuals’ interest and provides a change of pace while continuing to make progress toward desired goals. • Principle of Reversibility • “Use it or lose it” – inactivity leads to gradual erosion of benefits achieved. • Principle of Individuality • Individuals respond differently to exercise and will vary in their rate of improvement and levels of achievement. • Principle of Recovery • Rest allows the body to recover and adapt to the changes placed on it. • Principles of Safety • Safety is paramount.

19. Planning a Fitness Program • Threshold of Training • Minimal level of exercise needed to achieve desired benefits. • Target Zone • Defines the upper limits of training and the optimal level of exercise. • Needs and goals of the individual • Program should meet the goals of the individual. • FITT Formula

20. FITT Formula • Frequency • Number of sessions each week (i.e., how often). • Intensity • Degree of effort put forth during exercise (i.e., how hard). • Time • Duration of activity (i.e., how long). • Type • Mode of exercise being performed.

21. Cardiorespiratory Endurance • Body’s ability to deliver oxygen effectively to the working muscles to perform physical activity. • Most important component of health fitness. • Helps prevent hypokinetic disease. • Concerned with the aerobic efficiency of the body.

22. Cardiorespiratory Endurance

23. Target Heart Rate Zone • HRMAX= 220 bpm – age • Target zone = 55% to 90% HRMAX • Lower threshold target HR= HRMAX x 55% • Upper threshold target HR= HRMAX x 90%

24. Body Composition • Percentage of body weight composed of fat as compared with fat-free or lean tissue. • Obesity is associated with numerous health problems and earlier mortality. • Determination of the cause of obesity is important.

25. Body Composition • Body composition is influenced by nutrition and physical activity. • Energy balance is important to achieving a favorable body composition. • Energy expenditure through: • basal metabolism (maintenance of essential life functions) • work (including exercise) • excretion of body wastes

26. Body Mass Index • Estimated – • Weight in pounds X 703 divided by height in inches squared • Often used in large scale surveys because of ease of collecting large amounts of data.

27. Energy Balance • Number of calories taken into the body as food minus number of calories expended. • Caloric Expenditure: • Neutral balance • Caloric intake equals expenditure. • Positive balance • More calories consumed than expended. • Negative balance • More calories are expended than consumed.

28. Body Composition Improvement • Decreasing percentage of fat. • Decrease caloric intake through diet. • Increase caloric expenditure through physical activity and exercise. • Moderate decrease in caloric intake and moderate increase in caloric expenditure. • Follow sound practices. • Obsession with weight loss, in conjunction with many other factors, may contribute to the development of an eating disorder.

29. Measurement of Body Composition • Hydrostatic weighing • Skinfold measurements • Body mass index (BMI) • Dual-energy x-ray absorptiometry (DXA) • Bioelectrical impedance

30. Muscular Strength & Endurance • Muscular strength is the ability of a muscle or a muscle group to exert a single force against a resistance. • Muscular endurance is the ability of a muscle or muscle group to exert force repeatedly or over a period of time. • Maintenance of proper posture; protect joints. • Production of power to enhance performance. • Use it of lose it!

31. Exercises • Isometric Exercises • Muscle exerts force against an immovable object. • Static contraction. • Isotonic Exercises • Force is generated while the muscle is changing in length. • Concentric and eccentric contractions. • Isokinetic Exercises • Contractions are performed at a constant velocity

32. Development of Muscular Strength and Endurance • Principle of Overload is critical. • Repetition - performance of a movement through the full range of motion. • Set - number of repetitions performed without rest. • Strength • Low number of repetitions with a heavy resistance. • Endurance • High number of repetitions with a low resistance

33. Muscular Strength and Endurance

34. Flexibility • Maximum range of motion possible at a joint. • Joint specific: better range of motion in some joints than in others. • Can prevent muscle injuries & low-back pain. • Decreased flexibility can be caused by: • Sedentary lifestyle (lack of use of muscles) • Age • High amounts of body fat • Stress

35. Improvement of Flexibility • BallisticStretching • Momentum generated from repeated bouncing to stretch. (Not recommended) • StaticStretching • Slowly moving into a stretching position and holding for a certain period of time (10-30 seconds; 5 times). • Contract-relaxTechnique • Relaxing of the muscle to be stretched by contracting the opposite muscle (hamstrings/quadriceps) • Measurementof Flexibility - goniometer

36. Flexibility

37. Developing a Fitness Program • Medical conditions, such as heart disease, diabetes, and asthma must be taken into account. • Consider the participant’s fitness needs and goals. • Activities selected should allow participants to achieve the desired fitness goals while maintaining interested and enjoyment. • Attention must be directed to educating participants about the principles of designing a personal exercise program, assessing their own fitness, and resolving personal fitness problems.

38. Effects of Training • Lower oxygen consumption • Lower pulse rate • Larger stroke volume • Lower rise in blood pressure • Slower respiration rate • Lower rate of lactic acid formation • Faster return to “normal”

39. Environmental Considerations • Hot and humid weather • Use extreme caution • Heat cramps, heat exhaustion, heat stroke • Fluid replacement • Adaptation • Extreme cold weather • Heat conservation • Hypothermia • Frostbite

40. Nutrition and Fitness • Nutrients • carbohydrates • fats • proteins • vitamins • minerals • water • Maintaining water balance is important. • A well-balanced diet is necessary to obtain all the nutrients required by the body.

41. Nutrition • Food pyramid offers guidelines for eating a balanced diet. • Current U.S. diet is too high in fat, cholesterol, sugar, and sodium while lacking in carbohydrates and fiber. • Carefully monitor caloric intake AND caloric expenditure. • Special diets for special situations.

42. US Dietary Guidelines - 2005 • Consume adequate nutrients within caloric needs. • Maintain body weight within a healthy range. • Engage in regular physical activity (PA). • 30 minutes of moderate-intensity PA/day to reduce risk of chronic disease • Greater health benefits can be accrued from engaging in PA for a longer time and/or at a greater level of intensity

43. US Dietary Guidelines - 2005 • Consume a sufficient amount and variety of fruits and vegetables. • Consume at least half of your grains from whole grains. • Consume 3 cups/day of fat-free or low-fat milk or equivalent mild products. • Limit consumption of saturated fatty acids, trans fatty acids, and sodium. • Consume potassium-rich foods. • Drink alcoholic beverages in moderation. • Safely prepare foods to avoid illness.

44. Ergogenic Aids • Work-producing substances or phenomena believed to increase performance. • Used to enhance energy use, production, and/or recovery in quest for improved performance. • Forms of Ergogenic Aids: • Mechanical • Psychological • Pharmacological • Physiological • Nutritional

45. Caffeine • Stimulant, restricted by IOC – standard up to 6 to 8 cups of coffee. • Enhances muscle tension development, increased alertness, decreased perception of fatigue, increased endurance performance. • Effect depends on dosage and amount of caffeine athlete typically consumes. • Side effects – very rapid heart rate, diuresis, insomnia, nervousness, diarrhea, anxiety.

46. Carbohydrate Loading • Used in endurance events lasting 60 to 90 minutes or longer in order to maintain pace and delay fatigue. • Change training regimen and modify diet to eat more complex carbohydrates than normal in order to store additional glycogen in muscles and liver to provide extra energy. • Pre-event meal – 1 to 5 grams of carbohydrate per kilogram of body weight 1 to 4 hours prior to event.

47. Hydration, Energy & Sports Drinks • Proper hydration is important for safety reasons and to improve performance. • Fluid replacement during exercise is associated with lower heart rate, body core temperature, and levels of perceived exertion. • Water – 4-6 ounces for every 15-20 minutes of exercise. • Sports and/or energy drinks – add fluid as well as replace lost electrolytes and supply additional carbohydrates.

48. Creatine • Used in an effort to increase stores of muscle phosphocreatine and have more fuel available to support short, high intensity activity. • Used in conjunction with a resistance training program to maximize muscle strength and increase fat-free mass. • ACSM – creatine supplementation enhances exercise performance in events involving short periods of extremely powerful activity, especially during repeated efforts.

49. Anabolic-Androgenic Steroids • Synthetic forms of male hormone testosterone – testosterone secreted by testes is responsible for the development of masculine characteristics and promotion of growth of tissue, muscle mass, weight, and bone growth. • Taken orally or injected in 10 to 100 times the recommended therapeutic dosage. • Banned by IOC and some sport organizations. • Serious side effects, some irreversible, associated with chronic use including: increased risk of heart disease, liver tumors, cancer, hypertension, mood swings, aggressive behavior.