(CNN) - Many of us made exercising part of our New Year's resolution. But what do you do when you get sick?
Regular exercise is good for the immune system, helping us fight off simple infections such as colds.
So should you work out when you're sick? Experts say it depends on how sick you are.
The Mayo Clinic says a good rule of thumb is to use the "neck rule" as your guide.
If your symptoms are above the neck, such as a stuffy nose or sneezing from a mild cold, then you're generally OK. But if your symptoms are below the neck such as a bad cough, fever, muscle aches or nausea, exercising is not recommended. The exertion could make things worse.
Also, pay attention to how you feel. If mild symptoms get worse, give yourself a break and try another day.
If exercise is agreeing with you, it may still be a good idea to lower the intensity. If you're a runner, take it down a notch. If you like fitness walking, slow it down a bit.
If you lift weights, experts suggest you workout at home instead of at the gym so you don't infect others.
If you've been sidelined because of an illness, don't sweat it. Fitness experts say getting back into shape should be fairly easy.
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