Of course, as with anything, moderation is key. You don't want to run with pain or when injured.
From CNN:
"Moderate [running], three to five miles at a time, three times a week will actually help your joints to be more resilient and function a little bit better," says Dr. Amadeus Mason at Emory Sports Medicine Center in Atlanta, Georgia. But he stresses that keeping the joints healthy in the first place may be the key to running longevity.
That includes not running through pain, and resting if you have an injury, something Tuttle takes seriously. "I try to rest maybe if I'm having some specific pain that seems to be over a couple of days," she says.