Exercise and Illness
There's an interesting relationship between exercise and illness. Generally, exercise is good for the immune system. People who don’t exercise or exercise very little are sick more often, and stay sicker longer than exercisers. Moderate exercisers have fewer infections such as colds, flu and stomach bugs. However, people who exercise more than 8-10 hours a week become more prone to illness than even non-exercisers.
Moderate exercise stimulates the immune system, boosting the number and activity of infection-fighting immune cells. But, researchers aren’t exactly sure why people who exercise more, experience increased illness. Some reasons include more mental stress, less sleep, increased travel, weight loss and inadequate nutrition that come with an aggressive exercise regimen.
Also, following strenuous exercise athletes enter a period of time during which they are more susceptible to illness; this is referred to as the ‘open window’ and seems to vary from 3 to 72 hours.
Therefore, people who exercise frequently (more than 8-10 hours a week) need to take additional steps to protect their immune system. Exactly what athletes can do to boost their immune systems is a growing area of research, and there are a number of options you can use.
The most important way to boost your immune system is by paying close attention to recovery. More specifically, eating a mixture of carbohydrates and protein (especially branched chain amino acids) immediately following exercise has been shown to benefit the immune system.
The amino acid glutamine has gained a lot of positive research attention for its role in protecting against exercise-induced illness. We mix a bit in with our sports drink during long runs or rides, and also add it to our post-workout smoothies to ensure we get plenty of it.
Oxidation, or the production of free radicals, commonly occurs with more intense exercise and this has been linked to poor immune function. Consuming plenty of antioxidants is important to halt this process. You can add a scoop of either Greens First or Greens First Berry to your post-workout recovery drink to stop the production of oxidants, which occurs for hours after exercise.
Vitamin D is very important for the immune system. It plays a vital role in warding off viral infections (which are typically the cause of 90% of sicknesses that we get). You should definitely start supplementing staring in October through the winter months, and even in the summer if don’t get much sun.
If you find yourself getting sick more often as your training increases then following some or all of the above recommendations will be important to keep you healthy. Don’t get sidelined by a bunch of illnesses if you are training for something big!
If you want to read more about the immune system and exercise, here are two detailed papers written by Dr. Barker.