Exercise and the Common Cold
Too Much Exercise May Increase Colds
This isn't a problem for most of us, but if you're trying to reduce the number of colds, make sure you take time for rest and recovery after periods of intensive training.
Your immune system fights most effectively when it isn't stressed. Research confirms that a moderate exercise program may increase immunity and your resistance to respiratory infections. But scientists also note that athletes who train rigorously without recovery are more susceptible to viral infections like colds or flu.
While immunity is boosted when you work out moderately, the opposite may be true for elite or high-performance athletes such as marathon runners, swimmers, and other athletes that push their physical limits with intense training without sufficient recovery. For example, there's evidence of suppressed immunity during times of prolonged and intense exercise training with an increased number of upper respiratory tract infections.
When workouts become stressful or excessive, there can be decreased amounts of white blood cells circulating throughout your body and increased amounts of the stress hormone cortisol, which may inhibit the ability of certain immune cells to work properly.
When Should You Call the Doctor About Exercise and Colds?
If you exercise with a cold and have any of the following symptoms, it's important to stop and call your doctor:
Stop and seek emergency medical help if you have: