Increased aerobic and anaerobic enzymes
Long-Term Exerecise brings about a number of cellular changes that enhance the ability if muscle tissue to generate ATP. Cellular adaptation such as the increase in size of mitochondria is usually accompanied by an increase in the level of aerobix system enzymes. A combination of these changes probably explain why an athlete can sustain prolonged periods of aerobic eercise as a result of longer-term training. The anaerobic system also undergoes a number of changes, including an increase in enzymes that control the anaerobic phase of glucose breakdown. |
Increased use of fats as an energy source
Fat is the primary energy source during low-intensity exercise. Fat combustion powers almost alll exercise at approximately 25% of aerobic power. Fat oxidation increases if exercise extends to long periods, as glycogen levels deplete. When considering the effects of long-term exercise the trained athlete has a gerater opportunity to burn fat as a fuel than the non-trained athelete. |