Regular exercise is a big part of a healthy lifestyle. Sometimes, though, a cold or worse, the flu can hit even the most active person. If you’ve developed an exercise habit or are in training for an event like a marathon, you may want to power through an illness to stay in your routine. That might not be a good idea depending on the severity of your symptoms, however. Here are some things to think about when considering exercising when you have a cold or the flu.

“Above the Neck”

The Mayo Clinic suggests that if your symptoms are “above the neck,” meaning that they consist of a runny nose, nasal congestion, a mild sore throat, sneezing, or a combination of these, it’s generally all right to exercise. Make sure that you have plenty of tissues and water handy.

Clean up After Yourself

Even with minor symptoms, respiratory infections are highly contagious. Keep your distance from others–six feet is a good measure. Carry some antibacterial wipes to clean equipment and benches after your gym workout. You may want to work out at home until your symptoms go away.

Lower the Intensity of Your Workout

Even if you’re feeling relatively okay, you shouldn’t plunge right into intense activity. Start slow, gradually increasing your speed and tempo to a bearable level. Don’t be surprised, however, if you find yourself tiring much more quickly than you do when you’re well. Taking a nice long walk or a leisurely bike ride still counts as cardio and is a nice change of pace.

When Shouldn’t You Exercise?

While “above the neck” symptoms are commonly mild, if your symptoms include chest congestion, a heavy cough or stomach upset, stay out of the gym and off the track. Also, stay home if you have a fever and general body aches, as these are usually symptoms of the flu. Fever is your body’s main weapon for killing infections by drying up moisture in your body. Workouts do the same thing, and pulling out too much moisture can slow down your recovery. If you have a fever, you should wait until it subsides and your temperature stays down for 24 hours before trying to resume your workouts.

The best rule of thumb is if you don’t feel well, stay home and rest. If you’re coming off a heavy cold or the flu, visit your doctor for advice about when you can start working out again. Take it slow, listen to your body, and soon you’ll be back to your routine.