One of most frustrating things about getting sick is the interruption in your exercise routine. If fitness was part of your New Year’s resolution, you have established a regular routine and habit of movement. We notice the weather is starting to turn as cherry blossoms bloom and temperatures begin to raise, which only increases our desire to take our workout out of the gym.
And then —
Your child, your co-worker, that random stranger gifts you the sniffles.
Should you can your workout if you are sick? Well, It depends on your overall symptoms.
Light Coughing and/or sneezing: Give it a try. If your energy is fine and you can breathe, you can exercise. You may want to have a lighter workout, though. If your coughing is deep within the chest and more of a consistent “hacking” nature then stay at home.
Body Aches and/or Deep Fatigue: Skip it. If you are approaching your workout sore and 
exhausted, it isn’t going to get better. Your form will be off and you will not only increase your risk of injury, but may prolong your illness.
Fever and/or chills: Skip it. Stay at home, have some soup, rest!!! This holds true even if green light symptoms are also present.
Runny Nose and/or Congestion: While this can be quite an annoyance, it doesn’t have to stop you from exercising if you feel up to it.
Nausea, upset stomach: Lay down, drink some ginger tea and call it a day. The jostling nature of physical activity is not likely to help you help you out!
Sore Throat: Go for it! If no fever is present, the increased body temperature of exercising may eradicate whatever nasty bug is settling in your throat.
As a general rule of thumb – if symptoms are present above the neck, feel free to exercise. If they are manifesting below the neck, its best to stay home. If you decide to work out, plan on exercising half your usual time, going
half-speed on the treadmill or stationary bike, and backing off on the
weights until you regain your health. If you’ve been out sick and are feeling better, keep it light and easy until your energy and stamina return fully.
Whenever you are ill make sure your immune system is supported with LOTS OF WATER. If your throat is tender, you may find hot beverages particularly comforting. Take a thermos to the gym with warm water and lemon juice. Also, remember to take those extra precautions to prevent your illness from spreading – wipe down handles and equipment, wash your hands often, and cough into your elbow or armpit to prevent germs from spreading.
Great answer to a commonly asked question! I’ve not seen much written about sickness and exercise, but all of us avid exercisers have been there. Sometimes you’ve just got to rest. No one wants to struggle through a workout feeling bad only to wake up the next day feeling even worse.
Evolution Personal Training