Introduction: Exercise Physiology 101 (01:51)

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Carl Foster will address the benefits of exercise and issues that might impact it. He originally planned on obtaining his MD, but decided to pursue a PhD. He taught internal medicine fellows how to perform stress testing and cardiac rehab.

What is Exercise Physiology? (03:57)

Foster provides an overview of how a skeletal muscle contracts. Muscles respond differently because of architecture. Fast twitch muscles provide quicker latency and greater peak tension; slow twitch muscle fibers are recruited first for easy activities like walking.

Motor Control (03:46)

Athletes can recruit fibers in unique ways to produce desired movements. Foster describes the myosin-actin relationship in muscle contraction. Muscle fibers require adenosine triphosphate (ATP) for each twitch.

Ensuring ATP Availability (03:35)

Cells can make more ATP through the phosphagen, mitochondrial, and glycogen processes. Movements like standing up and walking use the phosphagen system. Patients afflicted with Crohn's disease cannot use glycogen to create ATP.

Defense of Intramuscular ATP Concentration (03:23)

Phosphagen and glycogenolytic processes provide anaerobic ATP; mitochondrial functions are for high-intensity exercise. Karlman Wasserman was the forefather of exercise physiology. Oxygen needs to circulate to the correct areas to make ATP.

Acute Responses to Exercise (04:00)

The two types of acute cardiovascular responses to exercise are incremental and steady state. Stress tests have patients pedal until they are exhausted. Acid-base balance and buffering impacts exercise strategies.

Redistribution of Blood Flow (03:49)

Increased cardiac output pushes blood to the muscles that need to make ATP and to the skin to regulate body temperature. Foster describes how the brain controls multiple organ systems to walk and obtain feedback from the body.

Why All the Responses? (04:02)

Exercise causes homeostatic responses like substrate depletion, metabolite accumulation, and hyperthermia. The body adapts to chronic exercise by moderate to large homeostatic disturbances.

Responses to Chronically Performed Exercise (05:07)

Exercise training makes an individual healthier. Maximal oxygen intake in a sedentary person increases by 25% after six months. Foster explains the molecular biology when a person exercises; testosterone self-regulates the process.

Training Schematic (03:58)

The cell creates a homeostatic disturbance when it uses ATP. MRNA informs the nucleus of the imbalance. Foster describes how the body needs to train and then recover to create adaptations; 30 minutes of moderate intensity exercise every day of the week is recommended.

Pathophysiology and Exercise (03:01)

Athletes get injured. Wasserman's gear wheel model describes issues that could happen in exercise. Foster explains that patients need to remain on the treadmill until the problem occurs or a physician cannot diagnose it.

Exercise is Medicine (05:37)

An hour a day of exercise makes individuals healthier. Foster describes literature on exercise physiology from Frank Booth. Exercise changes gene expression in a positive manner.

Credits: Exercise Physiology 101 (00:25)

Credits: Exercise Physiology 101