16 Dec What You Need to Know About Exercise & Immune Function

Your immune system acts to prevent disease, inflammation, and infection.  An underlying objective of your training should actually be limiting immune system suppression. What I mean by this is blunting your body’s response to inflammation and a heightened resistance to infection.   One of the functions then of the human immune system is to protect the body from inflammation and infection, which is increased following strenuous exercise, especially exercise where muscle damage occurs, as with moderate or high intensity exercise.

Successful recovery to improve immune function and prevent illness and/or injury is a key factor in exercise training, especially when starting out or as exercise program intensity begins to increase.  Strategies to improve immune function certainly include proper nutrition, which can play a major role in recovery and prevention of immune system dysfunction.  Your immune system in closely linked to your body systems that control hormonal responses, as well.  For example, during strenuous exercise, the (stress) hormone cortisol is released and this hormone is closely related to immunosuppression (shutting down your immune system), which is NOT what you want to occur. Cortisol is thought to lower the activity of many important cells in the immune system that are responsible for fighting infection.

Interestingly, glucose (carbohydrate) supplementation can have a significant effect on regulating cortisol during strenuous exercise.  So, glucose can limit the immunosuppression effects of exercise, which has been shown to be the case in research studies.  What is the optimal strategy to limit immune dysfunction?  That really depends on the type of training you are doing. If you are doing moderate intensity aerobic exercise, a sound strategy may be to ingest small portions (4mL/kg recommended) of carbohydrate solution every 15 minutes during exercise.  This will help to maintain muscle glycogen and blood glucose levels.  Additionally, it may be beneficial to supplement before and after exercise, as well.  Again, this will depend on your goals and level of intensity with training.  Maintaining blood glucose levels will assist in preserving immune function and limiting cortisol levels, since cortisol levels can increase up to 5-fold during strenuous exercise.

Additionally, there is research in the area of using antioxidants, as well. Antioxidant research is a bit conflicting, however, there has not been show to be any detriment by supplementing with Vitamin C and Vitamin E (both powerful antioxidants). While there certainly is NOT a performance benefit with this type of supplementation, these antioxidants have been shown to decrease levels of CPK (Creatine PhosphoKinase), which is an important marker of muscle damage. Also, Vitamin C and Vitamin E have been shown to reduce free radicals, which are important in reducing muscle inflammation.

Proper nutrition, including the use of carbohydrate supplementation around your exercise program appears to be have the greatest effect on limiting markers of inflammation and blunting cortisol, which is immunosuppressive.  Additionally, using antioxidant supplementation (Vitamin C and E) may be beneficial, as well, and seems to make sense in limiting muscle damage, especially following moderate or high intensity exercise.  These are methods I have used and seemed to have:

• limited muscle damage,
• limited immune system suppression,
• and allowed for faster recovery following high intensity workouts.

I will discussing more specifics around this in the future and the benefits of proper workout nutrition and supplementation, as this is a highly important topic.  These are just a few strategies around workout nutrition.

What are your thoughts on this topic?  Questions, comments? Let me know.

That’s it for Day 16 of 31 Days of Smart Fitness.

See you tomorrow…Scott