You’re feeling under the weather. Coughing, stuffy nose, itchy eyes and a sore throat. You’re thinking you can exercise it out of you, but is that in your best interest?

Whether you're a novice or a pro, knowing when your body needs rest is an important component of training. Sometimes you just don’t know which will make you feel better, resting or moving. When you come down with an infection or contagious condition, you need to decide how exercise will affect your health, performance and the health of others around you.

Should you work out or sit it out?
Ask yourself if you really need to push it this time. When your body is fighting an infection, your performance and fitness benefits will likely be less than optimal. So why go to the trouble?

Missing a few exercise sessions is not going to affect your overall fitness status and resting may just be a better option for you and the guy next to you in the gym.

Sometimes, though, physical activity helps you feel better. For example, working out can sometimes temporarily clear a stuffed-up head. So if you think exercise might help, or if you can't bear to miss a workout, do a check of your symptoms.

If your symptoms are located "above the neck" -- a stuffy or runny nose, sneezing, or sore throat, for example -- exercise is probably safe. But keep it slow. If you feel better after 10 minutes, you can increase your speed. If you feel miserable, stop. Use common sense.

If your symptoms include: muscle aches, hacking cough, fever of 100°F or higher, chills, diarrhea, or vomiting, avoid exercise. Exercising when you have these symptoms will leave you feeling weak and dehydrated at best. Worse, you may risk such dangerous conditions as heatstroke and heart failure.

As much as we admire your spunk, resume exercising when the symptoms subside. Also, when recovering from an illness that prevented you from working out, it's important to ease back into activity gradually. A good rule of thumb is to exercise for two days at a lower-than-normal intensity for each day you were sick.

Keep Your Cooties
If you're on a team or have a workout partner, an additional concern is whether you will infect others. And if you're healthy, you may wonder about someone else infecting you. For common illnesses like the cold, practice common-sense hygiene like washing your hands frequently and directing coughs and sneezes away from others.

Stronger viruses like measles or herpes can be transmitted via skin-to-skin contact. If you may have such an infection, see a doctor for treatment and information about when to resume activity.

Other conditions can also spread readily. So in addition to regular hygiene, refrain from sharing water bottles and towels. You should also be properly immunized against diseases such as measles, mumps, tetanus, and rubella. And you may benefit from an influenza vaccine. Ask your doctor what immunizations you need.

Exercise Common Sense
As is often true, deciding to exercise when you are sick largely involves common sense. Taking precautions about spreading infection and listening to your body can go a long way in getting you back into action without serious problems.