6. Borderline Iron Levels May Be Hurting Your Running

Unexplained fatigue – when your times go up and your stamina goes down – could also be a sign of a thyroid problem, a bad viral illness, or an iron deficiency. While typical medical evaluations should pick up thyroid and viral issues, iron is trickier for runners. Fatigue can occur from iron levels at the lower end of normal, which some doctors may consider okay for non-runners because it doesn’t indicate anemia. But as stamina can still suffer, ferritin levels should also be checked. “Ferritin gives you an idea of what your total body stores of iron are and if it’s low than that suggests that you want to take an iron supplement,” Bolin says.

If you’re still reluctant to talk to your doctor or if your practitioner seems to be unnecessarily discouraging you from running, it may be best to find a new doctor, perhaps a sports medicine specialist. Clinicians should work with athletes to allow them to continue the sport they love; after all, the benefits of running far outweigh the risks. “Doctors ought to know that you’re doing it and they ought to be encouraging it,” Bolin says.

READ MORE ON: injury-prevention