Cold Cures Often Slow Many Exercisers Over-The-Counter And Prescription Drugs Can Produce Strength-Sapping Side Effects

Exercising with a cold is tough enough. Exercising with cold medicine may make it even tougher.

Side effects of many over-the-counter and prescription drugs may add to the strength-sapping effects of the illness, doctors say. And although the combination of exercise and drugs doesn’t create new side effects, it can make the standard ones more noticeable.

Common decongestants containing such substances as epinephrine can raise the resting heart rate, said Dr. Thomas L. Schwenk of the University of Michigan Medical School. And cold preparations almost always have antihistamines, which can make some people feel drowsy.

“They don’t balance each other out,” Schwenk said. “You can feel low motivation while your heart rate is up.”

Competitive athletes are most likely to tell a difference in their performance, Schwenk said. Serious non-competitive athletes probably would notice it, but recreational athletes might just think, “I’m not feeling well,” he said.

And the effect also varies from person to person, whether or not they exercise, said Dr. Gary I. Wadler of New York University. Some people “get really shaky and get insomnia. Others will have no effects except their nose stops running.”

Also, the side effects of many prescription drugs are similar to the less-powerful over-the-counter products. For instance, prescription decongestants may speed up the resting heart rate.

For an aerobic athlete, that’s bad news. “You achieve your maximal heart rate a lot sooner, and you get tired a lot quicker,” said Dr. Douglas B. McKeag of the University of Pittsburgh.

Antibiotics such as erythromycin don’t affect exercise performance. But they can in some cases cause fatal heartbeat irregularities when combined with other drugs such as astemizole, which is sold in such products as Hismanal.

Athletes looking for guidance on what drugs to take will have to ask a lot of questions, the doctors say. Physicians don’t think to ask about exercise habits when prescribing cold or flu medications, and athletes who buy non-prescription medications had better get used to reading labels, they say.

There may be times when it is wiser to just skip the workout, the doctors say. “The general advice is to assess whether you have symptoms from the neck up or the neck down,” Schwenk said.

It’s considered safe to exercise with neck-up symptoms (runny nose, sneezing) but not neck-down (deep coughs, chest pains, and gastrointestinal discomfort), Schwenk said.

“Listen to your body,” Wadler said.