There’s a link between moderate regular exercise and a strong immune system, but during cold and flu season, it’s also important to have some limits.

Symptoms of a cold — stuffy head, sore throat — don’t warrant an end to moderate exercise.

But when it comes to the flu, it’s best to rest. Signs of the flu (fever, extreme tiredness, muscle aches, swollen lymph glands) call for at least two weeks off from any intense exercise after symptoms go away, according to the American Council on Exercise.

Also, if you’re surrounded by germs, consider this: Too much intense exercise can temporarily tax your immune system and make you susceptible. Research shows that more than 90 minutes of high-intensity endurance exercise make the body produce hormones that suppress the immune system and make a person susceptible to illness for up to 72 hours after the exercise session, according to

— Anne Aurand, The Bulletin