Soon cool weather will bring its share of colds and flu viruses, and they’ll spread through the office like wildfire. But if you work out regularly, you’ll have an advantage when it comes to staying cold-free. Moderate amounts of exercise reduce the risk of being sidetracked by a cold or respiratory infection.
Exercise and Colds: Does Working Out Help?
According to a study published in the British Journal of Sports Medicine, people who exercise five or more days a week spend 46% fewer days laid up with a cold or respiratory virus compared to those who work out only once a week or not at all. Not only that, but fitter people also experience less severe symptoms when they do get a cold, and they recover more quickly. Other studies also confirm the beneficial effects of exercise for preventing the common cold.
What Type of Exercise is Best?
Aerobic exercise appears to be best for warding off colds and flu. Activities such as brisk walking, jogging and cycling fall into this category. Why does aerobic exercise have this added benefit?
Aerobic exercise activates the immune system and the activity of white blood cells and antibodies that fight off infection. It also increases the activity of natural killer cells, a type of immune cell that’s particularly effective for warding off viruses. This increase in immune surveillance against viruses returns to baseline after a workout, but the body may still stay on higher alert even after an exercise session is over.
Too Much Exercise Isn’t Better
Although aerobic exercise boosts the immune system, there’s a point of diminishing return. Overdo it and you could end up with even more colds and flu bugs. Research shows that marathon runners are six times more likely to get a cold or respiratory infection the week after completing a marathon.
Exerting yourself for long periods of time, 90 minutes or more appears to suppress the immune system for hours or days afterwards. This may be due to the release of cortisol, a stress hormone that suppresses the immune system. Prolonged exercise boosts cortisol levels more than shorter sessions of less than an hour.
The Bottom Line?
Exercise could be your best defense against colds and flu viruses this winter. Work out hard, but don’t overtrain. Working out too long or too frequently and not giving yourself time to recover can make you more susceptible to bugs and viruses. Exercise regularly, but do it in moderation to keep the sniffles away.
Br. J. Sports Med. 2010.
USA Today. “Exercise Fights the Common Cold, Study Finds”