Should you train when you have a cold?

The common guideline is the neck check: symptoms above the neck such as a blocked nose or mild sore throat usually mean light training is fine, while symptoms below the neck — chest congestion, productive cough, body aches — or any fever mean rest. Fever in particular is a firm stop, since exercising with one raises the risk of complications including, rarely, heart inflammation. When you do return, come back at reduced intensity for a few days rather than resuming where you left off. Missing a week costs almost nothing; training through a fever can cost far more.