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An Introduction to Exercise and Sport Physiology Exercise physiology studies how the body’s structures and functions are altered when exposed to acute and chronic bouts of exercise. Exercise or changing environmental conditions can be utilized to stress the body. Sport physiology applies exercise physiology concepts to an athlete’s training and performance. Thus, sport physiology is derived from exercise physiology. Early exercise physiologists Archibald V. Hill • Nobel Prize winner (1921) • Studied energy metabolism in isolated frog muscle • Conducted first studies on runners John S. Haldane • Developed methods of measuring oxygen use during exercise Harvard Fatigue Laboratory • Founded by biochemist Lawrence J. Henderson • Directed by David Bruce 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 David Bruce Dill Dr. D.B. Dill was the first director of the Harvard Fatigue Laboratory. The Scandinavian Influence Erik Hohwü-Christensen • Published important series of five research studies in the late 1930s on carbohydrate and fat metabolism Per-Olof Åstrand • Conducted studies on physical fitness and endurance capacity during the 1950s and 1960s Jonas Bergstrom • Reintroduced the biopsy needle in 1966 to study human muscle biochemistry Women in Ex Phys Bodil Nielsen Studied human responses to environmental heat stress and dehydration Barbara Drinkwater Studied environmental physiology and the physiological issues unique to female athletes Acute responses vs Chronic Adaptations Acute responses to exercise involve how the body responds to an individual bout of physical activity. Chronic physiological adaptations to training mark how the body responds over time to the stress of repeated bouts of exercise, referred to as training effects. Cycle Ergometer Makes it easier to assess blood pressure and collect blood because upper body is relatively immobile Results are not greatly affected by body weight or changes in body weight Treadmill Results in generally higher maximal physiological values—heart rate, ventilation, and oxygen uptake than cycle ergometer Swimming Flume Allows swimmers to closely simulate their natural swimming strokes while researchers collect data Reasearch on them : • Ergometers are used to measure physical work in standardized conditions • Treadmills and cycle ergometers are most commonly used Factors to consider during exercise monitoring Acute Responses to Exercise • Control environmental factors such as temperature, humidity, light, and noise • Account for diurnal cycles, menstrual cycles, and sleep and eating patterns • Use the correct ergometer to measure physical work in standardized conditions • Match the mode of testing to the type of activity the subject usually performs Reading and Interpreting 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 Graphs: • x-axis is the independent variable or factor that is controlled by the study design • y-axis is the dependent variable that will change depending on how the independent variable is manipulated 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 Research Methodology • Control group: does not receive the intervention and serves as the comparison group • Placebo group: receives an inert substance or treatment • Intervention group: receives the treatment of interest to the scientific research question • Crossover design: each group undergoes both treatment (intervention) and control trials at different times Historical Perspectives on Exercise Physiology Vesalius: Andrea Vesalius wrote book in 1543: Fabrica Humani Corporis (structure of the human body) was a landmark text which presented his findings on the human anatomy. Covered mostly anatomy but he did try to explain their functions as well. It was the beginning of modern anatomy as well as physiology. LaGrange Fernand LeGrange a French man who wrote the first ever published textbook on exercise physiology in 1889: Physiology of Bodily Exercise. Most of his expainatins to the bodys response to exercise was limited to speculation and theory, presenting little fact. Henderson Lawrence Henderson a biochemist founded the Harvard Fatigue Laboratory in 1927, but was not interested in heading the lab so he gave it to DB Dill. Dill o David Bruce (D.B.) Dill directed the Harvard Fatigue Laboratory. He was a biochemist from Stanford university. He was the directory of the research at HFL, a title he held until it closed in 1947. o He also aided Arlen Bock in writing the 3rd ed. of Bainbridges text on exercise physiology and believed this book shaped the program of the HFL. He had little experience with applied human physiology. o 1968 – wrote a chapter on history on phys of exercise that detailed many events and scientists who contributed to this field before founding the HFL. o At HFL conducted a study of distance runners aging. Showing that prior training offers little advantage to endurance capacity in later life unless a person continues to engage in some form of vigorous activity. Robinson Sid Robinson did first studies on exercise and again in 1939 who was a student at the HFL. He described the effect of again on max heart rate and oxygen uptake. Once HFL closed he opened his own lab in the USA Krogh August Krogh studied how living cells generate and utilize energy. He teamed up with Scandinavian lindenberg to conduct class ic experiments on raning topics from metabolic feuls for muscle to gas exchange in the lungs. He spent time at HFL but then had his own institute at the University of Copenhagen – August Krogh Institute. Hohwu-Christensen Erik Hohwu-Christensen moved to Stockholm to become the first physiology professor at the college of physical education at GIH. He directed at GIH. In late 1930’s he teamed with Ole Hansen to conduct and publish a serioes of 5 studies of carb and fat metabolism during exercise. These studies are cited freq, and are considered among the first and most important sport nutrition studies. He introduced Astrand to the field of exercise physiology, and was a mentor to many of the outstanding scientists known. He also worked together with Astrand and with other physiologists at the Karolinka Institute in Stockholm who studied clinical applications of exercise. Astrand Per-Olof Astrand was introduced to the field of exercise phys by Hohwu- Christensen. He did numerous studies related to physical fitness and endurance capacity during the 1950-60s. He became director of GIH once Hohwu retired. He did a study and wrote a book with his future wife 0 irma rhyming. During this time of 1960’s he proposed a plan to help runners store the max amount of glycogen called glycogen of carb loading. According to him athletes should prepare for an aerobic endurance competition by completeing an exhaustive training bout seven days before the event and for the next 3 days they should eat fat and protein almost excusevly and deprive the muscles of carbs; this increases the activisty of glycogen synthase, an enzyme responsible to glycogen synthesis and storage. Athletes should then eata carb rich diest for the remaining 3 days before the event. Because the glycogen synthase increased, increased carb intake results in greater muscle glycogen storage. Astrand Test is a submaximal cycle ergometer aerobic fitness test Drinkwater Barbara Drinkwater was an American female exercise physiologist who was among the first to conduct studies on female athletes and to address issues specifically related to the female athlete. Worked at U of California in Santa Barbara Played good role of attracting more women to the field of exercise physiology, and medicine. Bergstrom Jonas Bergstrom reintroduced the biopsy needle in 1966 to sample muscle tissue, this was a point in the study of human muscle biochemistry and muscle nutrition. This allowed physiologists to conduct histological and biochemical studies of human muscle before, during, and after exercise. Collaborated with Saltin studied the effects of diet on muscle endurance and muscle nutrition Chapter 1: Structure and Function of Exercising Muscle
"Exercise Physiology Midterm notes"