An Introduction to Exercise and Sport Physiology.

An Introduction to Exercise and Sport

Physiology

INTRODUCTION INTRODUCTION OverviewOverview

• 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 Focus of Exercise and Sport Physiologyand Sport Physiology

• Physiology is the study of the function of organisms.

• Homeostasis is the maintenance of a constant internal environment.

Focus of Exercise Focus of Exercise and Sport Physiologyand 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 Acute and Chronic Responses to Exerciseto 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 PhysiologistsEarly 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 PhysiologistsEarly 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 LaboratoryThe 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: The Harvard Fatigue Laboratory: Early MeasurementsEarly 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: The Harvard Fatigue Laboratory: Early MeasurementsEarly Measurements

Scandinavian InfluenceScandinavian 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 PhysiologistsScandinavian Exercise Physiologists

Photos courtesy of the authors.

Eric Hohwü-Christensen Bengt Saltin Jonas Bergstrom (left) and Eric Hultman (right)

Contemporary Exercise PhysiologistsContemporary 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 PhysiologistsContemporary 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 MilestonesExercise 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 PhysiologyWomen 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: ErgometersResearch: Ergometers

• Ergometers are used to measure physical work under standardized conditions.

• Treadmills and cycle ergometers are the most commonly used types.

Research: ErgometersResearch: Ergometers

Research DesignsResearch 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:Dose-Response Relationships:Cross-Sectional StudyCross-Sectional Study

Dose-Response Relationships:Dose-Response Relationships:Longitudinal StudyLongitudinal Study

Research: Confounding FactorsResearch: Confounding Factors

• Many factors can alter the body’s response to exercise.

• Examples: environmental conditions, time of day (diurnal variation)

Table 0.1Table 0.1

Table 0.2Table 0.2

Research: Tables and GraphsResearch: 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 GraphsResearch: 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 0.9Figure 0.9

Figure 0.10Figure 0.10