First of all, exercise – even a daily 45 minute walk four days a week – can cut your risks of catching colds. This advice from the American College of Sports Medicine (ACSM) is based on findings that people who do that amount of exercise take 25 to 50 percent less time off from work because of illness. What’s more, ACSM representative David Nieman says that it’s perfectly okay to exercise if you have a head cold (just be sure it hasn’t gone to your chest).
But if you do exercise while you’ve got a cold, don’t push yourself – walk instead of running. If you’ve got more than the sniffles – the cold has gone to your chest, you have aches and pains are running a fever – go to bed. And give yourself a break when recovering from even a mild bout of illness: take a few weeks off before you begin to exercise again.
The ACSM also advises exercising before getting a flu shot. Moderate physical activity will boost your immunity.