ABSTRACT
Cognizance of the acute and chronic responses to exercise gives an insight and an understanding of the physiological stresses to which the human body is subjected. To appreciate exercise responses requires a true systems approach to physiology, because during exercise, all physiological responses contribute to a highly integrated and totally supportive mechanism toward the performance of the physical stress of exercise. Human muscle fibers convert chemical energy from the food that we eat into mechanical energy. Energy transfer occurs from the release of energy trapped within chemical bonds. Adenosine triphosphate (ATP), the fundamental energy source for muscle cells, is stored at maximal levels, as well as significant amounts of creatine phosphate (CP) and glycogen, the stored form of glucose. When the muscle proteins actin and myosin engage in response to high-intensity, short-duration muscular activity, the ATP-CP system is activated in the sarcoplasm of the muscle cell.
