Reducing stress

Reducing Muscle and Immune System Stress

In the long-term, sports training strengthens muscles and the immune system. However, individual workouts damage muscles and can temporarily suppress immune system function. Fortunately, proper sports nutrition can minimize these effects and accelerate recovery from them.

Every athlete has experienced muscles soreness after training and, especially, competing. There are no fewer than three known causes of post-exercise muscle soreness. The primary cause is mechanical stress, which is an accumulation of microscopic tears to muscle fiber membranes and protein filaments that happen as a consequence of repetitive, intense muscle contractions. The body’s efforts to repair such damage entail increased blood flow to the area, and with increased blood flow comes inflammation, and with inflammation comes soreness.

A second cause of post-exercise muscle soreness is oxidative stress, also known as free radical damage. Oxygen is a highly reactive type of molecule. During intense exercise, an athlete’s rate of oxygen consumption increases dramatically. Many of the individual oxygen molecules consumed during exercise lose an electron and become freed radicals inside the body. These molecules are extremely unstable and must regain stability by pilfering an electron from a muscle cell membrane, thereby damage the muscle cell.

The hormone cortisol has also been linked to muscle cell damage. Cortisol is a hormone released by the adrenal glands in response to all forms of stress. Its main function is to release amino acids from muscle proteins and transport them to the liver for use as an energy source. The release of cortisol tends to occur in the latter portion of long workouts, when the preferred glycogen energy source has been depleted.

In addition to damaging muscle cells, cortisol suppresses immune system function by decreasing production of lymphocytes and antibodies. Several studies have shown a temporary (2-72 hours) decrease in immune system function in athletes following hard exercise, and cortisol is thought to be the primary culprit.

How can sports nutrition fight these negative effects of exercise? The best way to limit the release of cortisol is by consuming carbohydrate during and immediately following exercise. By doing so, athletes maintain higher levels of blood glucose, which slows the use of muscle glycogen and delays the need for the use of protein as an energy source. Again, consuming carbohydrate with protein in a 4:1 ratio can yield even more pronounced benefits by accelerating the delivery of glucose to the muscles. In one study, a 4:1 sports drink (Endurox R4) reduced post-exercise muscle damage 36% more than a conventional sports drink containing no protein.

Athletes can reduce oxidative stress by consuming a diet high in antioxidant vitamins and minerals such as vitamins A, C, and E, beta-carotene, and selenium. Several studies have shown that vitamin C supplementation reduces post-exercise muscle soreness in athletes and that vitamin E supplementation has a similar effect on indicators of post-exercise muscle damage. One way athletes can get extra antioxidants in their diet is by using a sports drink that contains them in high amounts.


Source:
Powering Muscle