When Not to Exercise

Are you too sick, tired, or sore to work out -- or are you slacking off?

From the WebMD Archives

Exercise does the body good, but it's not always a good idea. Some aches and pains can make working out a definite no-no. Knowing when to work out or when to wait it out can be perplexing.

“The key is to be able to listen to your body and the cues it is giving you and decide if exercise is right at that time,” says Katie Rothstein, MS, a Cleveland Clinic exercise physiologist.

Should you just do it, or call in sick to the gym? Here's some expert advice.

You've Got a Fever

Stay home and rest. A fever shows that the body’s immune system is battling an infection -- and doesn't need to deal with stress from exercise on top of that, explains Stephen Rice, MD, PhD, a fellow of the American College of Sports Medicine and the director of the Jersey Shore University Medical Center in Neptune, N.J. If you exercise anyway, be alert for overheating and  dehydration, since body fluids decrease when you have a fever. You probably also won't get a great workout, since a fever boosts your resting  heart rate, which leads to a less effective workout.

You've Got a Cold

A cold can make you miserable, but it doesn't rule out exercise. Experts say moderate-intensity workouts are OK when you have a common cold. If you go to a gym when you have a cold, use hand sanitizer and wipe off any surfaces you touch so you don’t contaminate your gym buddies. The bottom line: It's understandable if you choose to take it easy, but exercising with a cold doesn't seem to make you sicker.

You've Got the Flu

Head to your sofa, not the gym. Skip your workout until you recover. With the flu comes a fever, so heed the rule not to exercise when you have a fever.

You Had a Recent Asthma Flare-up

If the flare-up was due to a respiratory infection, skip your workout for a few days and see a doctor if symptoms persist. Otherwise, if your doctor has said exercise is safe for you, and your asthma is well-controlled, it may be appropriate to work out. Be sure to start slowly and warm up for 10 minutes. Low-to-moderate intensity, intermittent exercise, or indoor  swimming may be better choices if you have exercise-induced asthma. During your workout, stop exercising if you can't catch your breath or feel tired and weak. Always have a treatment plan in place. That may mean taking your  inhaler to the gym or even using it prior to exercise.


You Recently Had a Concussion

Do not exercise or participate in any sport until your doctor says it is safe to do so -- even if you feel OK. A concussion is a traumatic brain injury, and your brain needs to heal properly. “If another  head injury occurs due to exercise before the [concussion] has healed, the brain is put at an increased risk of swelling and potential catastrophic damage,” Rice says.

Your Old Sports Injury Is Bothering You

Skip the workout and see your doctor. This is usually not a good sign, especially if you have pain during activity, Rice says. Sudden pain requires immediate medical attention.

You Didn't Sleep Last Night and Now You're Too Tired to Exercise

Get out of bed and get moving. “A morning workout may be just what you need after a restless night to boost your energy level and get you ready for the day,” Rothstein says. But if you're always fatigued -- not just a bit tired, but to the point of not being able to function -- skip the workout and see your doctor. Extreme or persistent fatigue can be a sign of illness.

You Felt a Sharp Pain the Last Time You Worked Out

Do not work out until you see a doctor to rule out an injury. If you exercise anyway, you may make the injury worse. “Although it is expected to feel soreness after you work out, it is never OK to feel pain,” Rice says.

Your Back Hurts

Take it easy for a few days and see if your back feels better. Pay attention to what makes the pain better or worse: Does bending or twisting cause you to squirm or say ouch? Try to avoid those movements to promote healing, Rothstein says. If your pain continues or interferes with your daily activities, see your doctor.

Your Muscles Are Sore

You can go to the gym, but make it a light-intensity workout, such as walking instead of  running. It's also OK to skip your workout and rest, if the soreness is too severe. And if your muscles are super sore because you overdid it the last time you exercised, make a point of making your workouts more reasonable. You don't want your fitness habit to become a flash in the pan.


You're Pregnant

Ask your doctor about a safe exercise program.  Yoga, swimming, walking, and other low-impact and moderate-intensity exercises can be very beneficial during  pregnancy. Be sure to stay hydrated, take breaks, and avoid getting overheated. Avoid exercises that strain your back and belly, Rice says. Exercises that are off limits during pregnancy include contact sports and activities such as skiing, water skiing, bicycling, and horseback riding, due to the risk of falls and abdominal injury.

It's Been a Rough Week and You're Wiped Out

Exercise may help cut your stress and boost your energy. So put on your gym clothes and start a moderate workout. “After 10 or 15 minutes, chances are you will feel fine and want to continue,” Rothstein says.

Don't Rush Your Comeback

Don’t dive right back into your regular exercise routine after being sidelined by an illness or injury.

It takes a lot of energy to maintain muscle strength, flexibility, and cardiovascular fitness -- and little time to lose it. “Noticeable decreases in exercise capacity can be seen in as little as two to three weeks,” Rothstein says.

Return to exercise slowly and carefully.

That's what Shannon Hurt, a 32-year-old Atlanta mom, has been doing. An avid walker/runner, Hurt was a week away from participating in a 5k when a test revealed she had an irregular heartbeat and thickening of the heart muscle. Exercise was off-limits until more tests could be completed.

That was several months ago. Now, Hurt has a prescription for heart medication -- and doctor's orders to ease back into her workout regimen.

“The cardiologist said to slowly return to exercising, starting with walking for 20 minutes or so each day and build back up to running,” Hurts says. “He wants me to eventually get back up to 5 days a week at a minimum of 45 minutes of intense  cardio.”


Easing Back Into Exercise

Walking is a great way to return to exercise without overtaxing the body, Rice says. Here is his advice for returning to exercise from a break, injury, or illness:

  • If you were away from the gym for less than a week, start at 80%-90% of your original intensity and slowly increase it from there.
  • If your break lasted longer than a week, reduce your intensity to 50%-60% and increase by 10% each week.


“A safe rule is that a 10% per week increase in intensity and duration is safe for everyone. Some people may be able to advance more quickly than others,” Rice tells WebMD.

Many factors should be considered when determining how quickly you can return to exercise after a hiatus. They include the length of your break, your age, and previous fitness level. The more physically fit you were before your break, the more quickly you will likely be able to return to your previous level of activity. If you had a long-term illness, check with your doctor about any exercise limitations. Never exercise if you have chest pain, shortness of breath, or  dizziness.

Remember, there is a fine line between pushing yourself and pushing yourself too hard.

“More is not always better,” Rothstein says. Moderate exercise can help prevent, control, or improve some chronic illnesses such as  heart disease, cancer, or  fibromyalgia, but if you have an acute infection, rest is best.

WebMD Feature Reviewed by Louise Chang, MD on February 16, 2010



Katie Rothstein, MS, exercise physiologist, Cleveland Clinic.

Stephen Rice, MD, PhD, director, Jersey Shore University Medical Center, Neptune, N.J.

American Pregnancy Association: "Exercise Guidelines During Pregnancy."

American College of Sports Medicine: "ACSM Current Comment: Exercise and the Common Cold," "ACSM Current Comment: Exercise and Pregnancy," "ACSM Current Comment: Exercising with Allergies & Asthma."

News release, American College of Sports Medicine.

© 2010 WebMD, LLC. All rights reserved.


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