A. Moderate exercise helps some cold suffers feel better, mainly by temporarily clearing a stuffed head. However, there is no evidence that exercise can cure a cold. Actually, if the activity is too demanding, it could make things worse by weakening your ability to fight the infection. Also, there is no evidence that exercise prevents a cold.
Athletes get just as many colds as everyone else.
Common sense says when you have a cold or you feel sick you should take it easy. Start at about half speed. If you feel better after 10 minutes, you can gear up the intensity. If, however, you don't feel well, stop, and put off the exercise for another day. And when you are feeling better, ease back into you program.