5) You keep getting sick
If you’re sidelined by illness more than usual, especially repeated bouts of the same virus, it could be a sign of overtraining. Amping up your mileage or the intensity of your workouts can impair the immune system, says Gaudette, leaving you more susceptible to contracting colds, the flu, and other viruses.
6) You’ve got nagging aches, pains, or injuries
Think injuries just come with the territory when you’re a hard-core runner? Think again. “When ramping up your mileage or adding tough speed workouts, you have to give your structural system the time it needs to heal the tiny microtears,” says Gaudette.