An Introduction to Exercise and Sport Physiology

introduction Overview Focus of exercise and sport physiology Acute and chronic responses to exercise The evolution of exercise physiology Research: the foundation for understanding

Focus of Exercise and Sport Physiology Physiology is the study of the function of organisms. Homeostasis is the maintenance of a constant internal environment.

Focus of Exercise and Sport Physiology Exercise physiology is the study of how body structure and function are altered by exposure to acute and chronic exercise. Environmental physiology is the study of the effects of the environment on the function of the body. Sport physiology is the application of the concepts of exercise physiology to training athletes and enhancing sport performance.

Acute and Chronic Responses to Exercise Acute exercise is a single bout of exercise. Chronic adaptation is a physiological change that occurs when the body is exposed to repeated exercise bouts over a period of weeks or months. These changes generally improve the body’s efficiency at rest and during exercise.

Early Exercise Physiologists Archibald V. Hill Nobel Prize winner (1921) Studied energy metabolism in isolated frog muscle Conducted first physiological studies on runners Photo courtesy of American College of Sports Medicine Archives.

Early Exercise Physiologists John S. Haldane Developed methods of measuring oxygen use during exercise Known for his work in human physiology and respiration

The Harvard Fatigue Laboratory Founded by biochemist Lawrence J. Henderson Directed by David Bruce Dill (D.B. Dill) Focused on the physiology of human movement and the effects of environmental stress on exercise Most contemporary exercise physiologists can trace their roots back to the Harvard Fatigue Laboratory.

The Harvard Fatigue Laboratory: Early Measurements Collected expired air in a sealed bag known as a Douglas bag A sample of the gas from the Douglas bag was then measured for oxygen and carbon dioxide using a chemical gas analyzer.

The Harvard Fatigue Laboratory: Early Measurements

Scandinavian Influence Eric Hohwü-Christensen In the late 1930s, published an important series of five research studies on carbohydrate and fat metabolism Per-Olof Åstrand During the 1950s and 1960s, conducted studies on physical fitness and endurance capacity Jonas Bergstrom Reintroduced the biopsy needle in 1966 to study human muscle biochemistry

Scandinavian Exercise Physiologists Eric Hohwü-Christensen Bengt Saltin Jonas Bergstrom (left) and Eric Hultman (right) Photos courtesy of the authors.

Contemporary Exercise Physiologists John Holloszy and Charles Tipton Introduced biochemical approach to exercise physiology research First to use rats and mice to study muscle metabolism and fatigue Reggie Edgerton, Phil Gollnick, and Bengt Saltin Studied individual muscle fiber characteristics and their responses to training in rats and humans

Contemporary Exercise Physiologists John Holloszy Charles Tipton Phil Gollnick Photo of John Holloszy courtesy of American College of Sports Medicine Archives. All rights reserved. Other photos courtesy of the authors.

Exercise Physiology Milestones Peter Karpovich, Springfield College Helped introduce physiology to physical education Thomas K. Cureton, University of Illinois Helped support a rationale for using exercise to promote a healthy lifestyle Elsworth Buskirk, Penn State University Established The Laboratory for Human Performance Research in 1974

Women in Exercise Physiology Birgitta Essen Collaborated with Bengt Saltin and Phil Gollnick in publishing the earliest studies on human muscle fiber types Karen Piehl Among the first to demonstrate that the nervous system selectively recruits type I and type II fibers Barbara Drinkwater Among the first to address issues specifically related to the female athlete

Research: Ergometers Ergometers are used to measure physical work under standardized conditions. Treadmills and cycle ergometers are the most commonly used types.

Research: Ergometers

Research Designs Longitudinal research tests the same subjects and compares results over time. Cross-sectional research collects data from a diverse population and compares groups in that population. Longitudinal studies are often more accurate than cross-sectional studies, but are time-consuming and expensive.

Dose-Response Relationships: Cross-Sectional Study

Dose-Response Relationships: Longitudinal Study

Research: Confounding Factors Many factors can alter the body’s response to exercise. Examples: environmental conditions, time of day (diurnal variation)

Table 0.1

Table 0.2

Research: Tables and Graphs The title will identify what information is being presented. Units for each variable should be clearly presented. Graphs better illustrate Trends in data Response patterns Comparisons of data between subject groups

Research: Interpreting Graphs The x-axis is the independent variable or factor that is controlled by the study design. The y-axis is the dependent variable that will change depending on how the independent variable is manipulated.

Figure 0.9

Figure 0.10