What physiologic adaptations occur in response to athletic training?

Answer 1

Strength training (such as weight lifting) promotes muscle growth—helping increase muscle size and strength. Endurance training is especially beneficial to pulmonary and cardiovascular function and can help improve aerobic capacity (the maximum amount of oxygen the body can use during a specified period). Interval training, which involves alternating short, fast bursts of intensive exercise with slower, less demanding activity, helps improve both aerobic and anaerobic capacity. (Anaerobic capacity is defined as the ability to perform repetitive, high-intensity activity with little or no rest.) More specifically:
• Muscles of trained athletes use glucose more sparingly, and they are better able to use fatty acids as an energy source.
• Endurance training increases the number and size of mitochondria, the location of aerobic metabolism.
• Training increases maximal oxygen consumption (called VO2 max), which may help delay fatigue.
• Training strengthens the heart, resulting in more forceful and efficient cardiac function and better nutrient and oxygen delivery to muscles.
• The expansion of capillary blood vessels in muscles increases blood flow to muscle cells. The increased production of red blood cells in response to training further increases the oxygen-carrying capacity of the blood.