Dr. Jordan Metzl

If you’ve experienced burning pain in the forefoot that radiates into the toes, you may have what’s called Morton’s neuroma.

A swollen knee should send you to the doctor—but an important question in diagnosis is when did it start swelling: right after running or later the next day?

Road rash from a cycling crash is not an especially deep injury, but it can bleed and is definitely painful.

Ever get a sudden, intense, thunderclap headache during exercise or race? You’re not crazy.

Keep your mileage low if your current body weight is more than 5 percent over your ideal weight.

Pain can come on gradually (as a chronic problem) or suddenly from a forceful movement (as an acute injury).