Stuffy noses, hacking coughs and aches all over—cold and flu season has arrived. Though your body may be aching and your nose running like a faucet, it can be difficult to decide if you should continue your exercise routine or take a temporary break.

"We all know that exercise is key to good health, but there are times that your body may need a break," said Keith Veselik, MD, director of primary care at Loyola University Health System. "Having to slow down when you're sick is Mother Nature's way of saying, 'Don't push it,' and it's reasonable to pay attention to that."

Whether a person should exercise or not can be disease-specific, according to Veselik. When sick our bodies already are battling against an illness and that takes energy. For instance, adding the extra stress of exercising while sick can be dangerous for a person with a heart condition. A person with diabetes may need to monitor more often, especially if one is not eating and drinking normally. Being ill may raise glucose levels and exercise may lower them. If you do have a medical condition and are not sure whether you should exercise while sick, Veselik suggested you call your doctor.

Still, Veselik said a general rule is that it's OK to exercise if your symptoms are above the neck, such as a sore throat or .

"If you aren't feeling well but still want to exercise, lower your expectations about what you can do. You don't necessarily need to be in bed all day, but you can't expect to have the same level of energy as you would if you weren't sick," Veselik said.

But, it could be dangerous to exercise if you have the following symptoms:

  • Fever
  • or chest congestion
  • Body aches
  • Diarrhea or vomiting
  • If you feel dizzy or lightheaded when you stand up
When making the decision, he also suggested thinking about where you will be exercising and who will be exposed to your illness.

"Though sharing is usually a good thing, that's not the case when it comes to germs. If you are coughing and sneezing, just skip the Zumba class or basketball game and go for a walk or run by yourself instead," Veselik said. "Also, always wipe down machines at the gym. You never know who was using it before you."

He also warned to not get your expectations too high when returning to a normal .

"People need to pace themselves when getting back into their routine. You won't be able to do as much right away and that's OK. Initially, it should be 50 percent effort and 50 percent duration. Listen to your body and increase according to what it tells you," Veselik said.