This seems like a pretty good explanation of when to work out or just be sick!! Personally, If I feel fatigued, then my body is telling me to take it easy and try again another day!!
Is it OK to exercise if I have a cold but no fever?
from Edward R. Laskowski, M.D.Mild to moderate physical activity is usually OK if you have a cold but no fever. Exercise may even help you feel better by temporarily relieving nasal congestion.
As a rule of thumb for exercise and illness:
- Proceed with your workout if your signs and symptoms are "above the neck" — such as runny nose, nasal congestion, sneezing or sore throat. Be prepared to reduce the intensity of your workout if needed, however.
- Postpone your workout if your signs and symptoms are "below the neck" — such as chest congestion, hacking cough or upset stomach. Likewise, don't exercise if you have a fever, fatigue or widespread muscle aches.