EXERCISE PHYSIOLOGY

An exercise physiologist studies the acute responses and chronic adaptations of physical exercise conditions. Specifically, they focus on the effect of exercise on pathology (study and diagnosis of disease) and the mechanisms by which exercise can reduce disease progression. When working with athletes, the monitor and assess cardiovascular and metabolic effects and mechanisms of exercise, replenishment of fluids during physical activity, and exercise for cardiac and musculoskeletal rehabilitation.

Common terms:

Aerobic respiration: Requires oxygen to generate energy in the form of ATP; occurs in fives steps (glycolysis, oxidation of pyruvate to Acetyl Coenzyme A, Krebs cycle, electron transport chain, and oxidative phosphorylation)
Anaerobic respiration: A form of respiration without the use of oxygen
ATP: Adenosine Triphosphate transports chemical energy within cells; it is produced via cellular respiration and is known as the energy currency of cells

Carbohydrates: Main fuel source for high intensity exercise and main fuel source for muscle contractions

CP: Creatine Phosphate is a molecule that serves as a reserve of high-energy phosphates in the skeletal muscle and brain; it can anaerobically supply a phosphate grout to ADP in order to form ATP during the first 2-7 seconds following an intense muscular effort

Fats: Main fuel source for long duration, low to moderate intensity exercise and help access stored carbohydrates during high intensity exercise
Glycolysis: The first stage of both aerobic and anaerobic respiration; glucose is converted into a 3 carbon sugar (pyruvate) in ten reduction/oxidation reactions; energy released is used to for ATP and NADH
Lactic acid: A chemical compound playing a significant role in many biochemical processes; byproduct of anaerobic respiration

Protein: Biochemical compound that is a sequence of amino acids that are the building blocks of the body; proteins repair and rebuild muscle that is broken down during exercise and to help optimize carbohydrate storage in the form of glycogen

VO₂ max: The maximum capacity of a person’s body to transport and use oxygen during periods of exercise; reflects physical fitness of a person

Energy Pathways
The body cannot easily store ATP, so the body needs to continually for ATP during exercise through aerobic or anaerobic respirtaiton.

1.      ATP-CP: the phosphate system; the combination of ADP and CP which are both stored in muscles create ATP, but it only lasts about 2-3 seconds and the re-synthesis of ATP from CP will continue unto CP storage are depleted

2.      Anaerobic Metabolism: glycolysis and lactic acid production; production of ATP without oxygen once the CP reserves are depleted; it makes energy for a short amount of time during high intensity activity or until lactic acid build-up reaches a threshold with muscle pain and fatigue

3.      Aerobic Metabolism: endurance exercise energy production; oxygen from the Krebs cycle and the electron transport chain manufacture ATP from glucose; it is the prime energy source during endurance activities, but it is slower than anaerobic enrgy because it relies on the circulatory system to transport oxygen to muscle cells to generate ATP