While a new study shows that exercise plays a big part in preventing some illnesses during cold and flu season, it's not always a good idea to continue your intense workouts when you do get sick.
If you work out for 30 to 60 minutes most days, then the number of days you're likely to be out sick during the cold and flu season this winter will be reduced by at least 40 percent, according to David Nieman of the American College of Sports Medicine in Indianapolis.
In two controlled studies, one of young and the other of elderly women, those who walked briskly for 35-45 minutes five days a week for 12 to 15 weeks experienced about half the days with cold symptoms as did the women in the sedentary control groups, he said.
But if you do get the sniffles, should you work out?
That depends, says Moira Davenport, who practices sports medicine and emergency medicine at Allegheny General Hospital, and Jeanne Doperak, a sports medicine and family practice physician at UPMC.
"If you have just a little head cold, it's all right to exercise," Dr. Davenport said. "But it should be more of a moderate effort, just enough to get your blood flowing but not so much to stress your immune system."
"We come up with a million reasons why not to exercise," Dr. Doperak said. "The truth is there are not many that are actually legitimate."
Both doctors agreed that people should not exercise when they have a fever or if they have the generalized muscle aches and pains and other symptoms that accompany flu.
Even if you have minor symptoms of a cold, you shouldn't push it, the doctors said.
"When you're sick, your workout should not be a struggle," Dr. Doperak said.
"There is an overtraining syndrome, where the immune system can actually deteriorate, and people get sick more often," she said.
If you exercise with a cold, it's best to do so indoors and make sure you drink plenty of water, Dr. Davenport added.
"When you have a cold, you are breathing through your mouth more than normally, so you are losing more fluids than you would be normally," she said. "It's really important for you to keep up with that."
Exercise can also be beneficial when you get a flu shot. Dr. Nieman suggests that you engage in moderate intensity exercise before getting a shot. The body responds better to the vaccine after exercise and provides a boost in immunity, he said.
Dr. Nieman's rule of thumb is that if your symptoms are restricted to the neck up (runny nose, sore throat), it's OK to engage in moderate exercise. But if you have a fever or general aches and pains, stay in bed.
If you have a serious bout with the flu, don't jump back into your exercise routine as soon as your symptoms fade, Dr. Nieman advises. Get at least two weeks of rest before easing back into your routine.
Jack Kelly: firstname.lastname@example.org or 412-263-1476.