How to Tell If You're Exercising Too Hard

After a hard workout or a new one, you may notice a dull pain in the muscles you used. That's normal—in fact, it's "when the magic happens," says exercise physiologist Amy Dixon. "You've caused microscopic tears in the muscle fibers, and as they heal, they become stronger." But discomfort can also be a sign that you pushed too hard. Follow our flow chart to learn when to give yourself a break.