What's Best: Exercise or Rest?

There's often nothing more energizing than a workout, but on some days you're better off taking it easy. Your body usually knows best -- just pay attention to what it's trying to tell you.

Your Status: "I have a twinge in my back."

When to Get Into Gear

With mild cases, you'll usually feel better after gentle exercise, says Jason Glowney, M.D., the medical director of the Boulder Center for Sports Medicine in Colorado. It gets more blood flowing to the area, which can reduce tightness.

When to Lie Low

See your health care practitioner first if you have severe pain or pain that radiates into your legs or glutes; numbness or weakness; or if you've recently been in an accident, says Glowney. Exercising could cause more damage.

Your Status: "My allergies are kicking in."

When to Get Into Gear

"If you're not having trouble breathing, it's fine to work out, but you might want to do it indoors or later in the day," says Sara Thyr, a naturopath based in Petaluma, California. Pollen counts are usually highest before 10 a.m.

When to Lie Low

If you have exercise-induced asthma and your symptoms aren't under control, or if you're simultaneously battling a cold or respiratory infection, skip your workout -- it could trigger an attack.

Your Status: "I just had acupuncture."

When to Get Into Gear

If you're seeing an acupuncturist for health maintenance, it's fine to work up a sweat post-treatment, says Catherine Austin, an acupuncturist in La Jolla, California. "Wait a few hours and eat a little something first."

When to Lie Low

Wait until the next day (or longer) if you're being treated for a condition that involves fever or a chronic problem that has left you feeling fatigued. "You want the strength you have to go toward the healing process," says Austin.

Your Status: "I'm coming down with a cold."

When to Get Into Gear

As long as you don't have a fever, and the symptoms are above the neck, such as a runny nose and sore throat, working out won't make your cold worse -- just don't overdo it. Stick with moderate activity, such as walking.

When to Lie Low

Chest congestion, fever, and body aches are signs that you should take a few days off. Research has shown that if you have the flu, exercise can make it worse. Once you begin to recover, ease back into your regimen gradually.