This is why you should skip exercise when you're sick.
However, intense exercise like a marathon, can suppress your immune function.
According to Time, experts recommend using exercise for prevention, not cure.
Research from Ball State University shows that a cold remains unaffected even after exercise.
If you have a flu or other ailments that cause a fever, you shouldn't exercise.
A body that has a viral infection should not be subjected to vigorous activity. It can exacerbate the situation or make the infection last longer.
Workout freaks and athletes believe that you can "sweat out a fever". Studies now show that this is a myth and it only makes things worse.
The physical stress from exercise makes the body's immune function to work more than normal to fight the disease.
Studies from Australia showed that athletes who continued to work out when they had a flu or a fever ended up developing chronic fatigue syndrome.
Should you have an infection, wait a week before you start exercising again.