Periods of heavy training are sometimes associated with the depressed immune function, and compromised immune function can be further aggravated by inadequate nutrition. Combining training with school or work can overtax your resources, stress your body, and compromise your ability to fight infection. A strong immune system should result in fewer colds and other viruses, and when you do get sick, should enable you to make a quicker recovery.
Fruits and vegetables contain hundreds of phytochemicals that provide many preventive health benefits and are also excellent sources of carotenoids that boost the activity of the white blood cells called lymphocytes. Beta-carotene can also be converted into vitamin A, an important nutrient for the immune system. Other nutrients important for a strong immune system are zinc, iron, and vitamins B6 and B12. A good daily multivitamin and mineral supplement providing 100 percent of the DVs ensures adequate nutrient intake.
Megadosing with vitamins and minerals can compromise the immune system, and excessive intakes of iron, zinc, and vitamin E are not advised. A balanced diet that includes a large variety of foods provides many nutrients that work together to keep your immune system healthy, and a moderate-dose supplement ensures that you are obtaining all the nutrients that you need.
Levels of certain stress hormones normally rise during exercise, but athletes who train in a carbohydrate-depleted state experience a greater increase in these hormones than those who are well fueled. Your immune system appears to function best when carbohydrate is available. Consuming carbohydrates during exercise also seems to diminish some of the immunosuppressive effects of intense training. Generally, strenuous exercise suppresses immune function and gives viruses a strong “window of opportunity” after a workout to gain a foothold in your body and start an infection. Besides replacing carbohydrate during training, practice optimal recovery nutrition guidelines as well.