I'm 57 and still love to run so it is important to pay attention to what my body is telling me. Having a good relationship with my chiropractor, massage therapist, and stretch therapist keeps me going. If I need to just walk for the day I do. If I need to rest, I do. Switching up distance and speed keeps those repetitive injuries at a minimum. I pay attention to any twinges and address it. Posture while working is important. Injuries can cause a ripple effect of more injuries so treat it right!