S.E. Riechman, Ph.D. Assistant Professor Web site: sriechman.tamu

1. KINE 433-503 Physiology of Exercise S.E. Riechman, Ph.D. Assistant Professor Web site: http://sriechman.tamu.edu

2. FYI: USA Today, 09/02/03

3. I N T R O D U C T I O N AN INTRODUCTION TO EXERCISE AND SPORT PHYSIOLOGY

4. w Note the differences between acute responses to exercise and chronic adaptations to training. (continued) Learning Objectives w Learn to differentiate exercise physiology and sport physiology. w Become familiar with the evolution of exercise physiology and its early scholars.

5. Learning Objectives w Learn what factors affect the body's acute response to exercise. w Understand the six basic principles of training. w Learn how to accurately read and interpret tables and graphs. w Learn whether cross-sectional studies or longitudinal studies are more accurate.

6. Exercise Physiology vs. Sport Physiology Exercise physiologists study how the body’s structures and functions are altered when exposed to acute and chronic bouts (i.e., training) of exercise using human or animal subjects. Sport physiologists apply exercise physiology concepts to an athlete's training and performance.

7. Historical Note on Exercise Physiology The earliest written record referring to the physiology of exercise: “Eating alone will not keep a man well; he must also take exercise. For food and exercise, while possessing opposite qualities, yet work together to produce health. For it is the nature of exercise to use up material, but of food and drink to make good deficiencies. And it is necessary, as it appears, do discern the power of the various exercises, both natural exercises and artificial, to know which of them tends to increase flesh and which to lessen it.” Hippocrates, Regimen in Health, ~400 B.C.

8. Historical Note on Exercise Physiology The earliest published use of the specific term, “physiology of exercise”: William Byford, On the Physiology of Exercise, American Journal of Medical Sciences, 1855

9. Early Exercise Physiologists Archibald V. Hill w British Nobel Prize winner (1921) w Studied energy metabolism and muscle physiology w First studies on runners

10. Harvard Fatigue Laboratory (U.S.) w Founded by Lawrence J. Henderson in 1927 w Directed by David Bruce Dill w Focused on the physiology of human movement and the effects of environmental stress on exercise w Pioneered studies that resulted in an explosion of interest in exercise physiology w Closed in 1947

11. Early Exercise Physiologists David Bruce (“D.B.”) Dill w Directed Harvard Fatigue Laboratory (HFL) from 1927-1947 w Later studied human tolerance to exercise in the desert and at altitude Sid Robinson w Studied exercise and aging while a student at HFL

12. Early measurements of exercise metabolism Smith, 1922

13. EARLY MEASUREMENT DEVICES Douglas bag for collection of expired air August Krogh measuring oxygen and carbon dioxide in expired air with a gas analyzer

14. Scandinavian Influence Erik Hohwü-Christensen w Published important early research on carbohydrate and fat metabolism Per-Olof Åstrand w Conducted studies on physical fitness and endurance capacity

15. Scandinavian Influence • Bengt Saltin • Contributed greatly to exercise and clinical physiology • Most cited exercise physiologist • Jonas Bergstrom • Reintroduced biopsy needle to study human muscle biochemistry

16. THE BIOPSY TECHNIQUE Local anesthesia Scalpel incision Needle insertion Tissue extraction

17. Thought Question In studies of muscle using animal models, the physiologist typically removes whole muscles or muscle parts for study. What are the advantages and disadvantages of this approach compared with studies using the biopsy technique?

18. Exercise Physiology and Physical Fitness Peter Karpovich w Introduced physiology to physical education Thomas K. Cureton w Taught many of today’s leaders in physical fitness and exercise physiology

19. Contemporary Exercise Physiologists John Holloszy, Charles Tipton, and Phil Gollnick w Introduced biochemical approach to exercise physiology research w First to use rats and mice to study muscle metabolism and fatigue

20. Contemporary Exercise Physiologists Philip D. Gollnick Washington State University 1934-1991

21. Women in Exercise Physiology Birgitta Essen w Adapted micro-biochemical methods for better studying muscle samples obtained with muscle biopsy Karen Piehl w Published several studies illustrating which fibers were activated during aerobic and anaerobic exercise

22. Women in Exercise Physiology Bodil Nielsen w Studied human responses to environmental heat stress and dehydration Barbara Drinkwater w Studied environmental physiology and the physiologi- cal issues unique to female athletes

23. Molecular Biology & Exercise Physiology Frank Booth and Ken Baldwin w Dedicated their careers to understanding the molecular regulation of muscle fibers w Contributed to what we now know of the genetic controls of muscle growth and atrophy

24. Contemporary Exercise Physiologists Jack Wilmore testing Peter Snell ~ 1972

25. Key Points Research Methodology w Laboratory research allows investigators to carefully control variables and use accurate equipment. w Field research allows for less control of variables and equipment, but the participant’s activities are often more natural.

26. w Makes it easier to assess blood pressure and collect blood because upper body is relatively immobile w Results are not greatly affected by body weight or changes in body weight Cycle Ergometer

27. Treadmill w Results in generally higher maximal physiological values—heart rate, ventila- tion, and oxygen uptake— than cycle ergometer

28. Swimming Flume w Allows swimmers to closely simulate their natural swimming strokes while researchers collect data

30. Acute Responses vs. Chronic Adaptations Acute responses to training involve how the body responds to one bout of exercise (for example, the increase in heart rate). Chronic physiological adaptations to training mark how the body responds over time to the stress of repeated exercise bouts (for example, the decrease in resting heart rate).

31. Homeostasis and Steady State Homeostasis: maintenance of a constant, unchanging internal environment by the physiological systems; normally only possible at rest; typically operate by negative feedback Powers and Howley, Exercise Physiology, 2004

32. Homeostasis and Steady State Homeostasis: maintenance of a constant, unchanging internal environment by the physiological systems; normally only possible at rest; typically operate by negative feedback Powers and Howley, Exercise Physiology, 2004

33. Homeostasis and Steady State Steady State: a constant internal environment that may be different than rest, for example during steady exercise Powers and Howley, Exercise Physiology, 2004

34. Physiological Importance of “Δs” (deltas) • Most physiological processes operate because of differences or gradients in the controlled variable, e.g.: • Blood flows through the circulatory system because of pressure gradients (i.e., ΔP) • Air flows in the respiratory tract because of air pressure gradients • Ions move across membranes because of concentration or electrical gradients • Heat moves from the skin to the surrounding air because of temperature gradients

35. Key Points Considerations in Research w Control environmental factors such as temperature, humidity, light, and noise. w Account for diurnal cycles, menstrual cycles, and sleep patterns. w Use ergometers to measure physical work in standardized conditions. w Match the mode of testing to the type of activity the subject usually performs.

36. Time of day 2 a.m. 6 a.m. 10 a.m. 2 p.m. 6 p.m. 10 p.m. Condition Heart rate (beats/min) Resting 65 69 73 74 72 69 Light exercise 100 103 109 109 105 104 Moderate exercise 130 131 138 139 135 134 Maximal exercise 179 179 183 184 181 181 Recovery, 3 min 118 122 129 128 128 125 Data from Reilly and Brooks (1990). An Example of Diurnal Variations in Heart Rate at Rest and During Exercise

37. Basic Training Principles Individuality—Consider the specific needs and abilities of the individual; everyone responds differently. Specificity—Training adaptations are highly specific to the type of activity and the volume and intensity of training. Disuse—Include a program to maintain fitness. Progressive overload—Increase the training stimulus as the body adapts. Hard/easy—Alternate high-intensity with low-intensity workouts. Periodization—Cycle specificity, intensity, and volume of training.

38. Reading graphs: understand the axes! • Steady state • Maximum (Max) • Threshold

39. Thought Question Considering the graph on the previous slide, can the person attain steady state during exercise at a power output of 300 watts? Explain your answer.

40. READING AND INTERPRETING GRAPHS

41. READING AND INTERPRETING GRAPHS

42. w Longitudinal studies are often more accurate than cross-sectional studies, but they can’t always be done. Key Points Research Methodology w Longitudinal research tests the same subjects and compares results over time. w Cross-sectional research collects data from a diverse population and compares the data for each group in that population.

43. CROSS-SECTIONAL RESEARCH In this study, high density lipoprotein-cholesterol (“good cholesterol”) was measured in groups of subjects undergoing different volumes of exercise

44. LONGITUDINAL RESEARCH In this study, HDL-C was measured over time in a group of subjects training with distance running and a group of sedentary persons

45. Thought Question What are the relative advantages and disadvantages of longitudinal and cross-sectional research designs?