Running is often blamed for “wearing out” the knees, but the evidence does not support the idea that recreational running inevitably causes knee osteoarthritis or progressive joint damage.
Research in runners is complicated by differences in age, training history, previous injury, body weight and running volume. Some observational studies find similar or even lower rates of knee osteoarthritis among recreational runners than among sedentary adults, but that does not mean running protects every knee.
The more immediate concern is usually injury rather than arthritis. Sudden increases in distance or intensity, inadequate recovery, previous knee injury and biomechanical factors can contribute to pain. Persistent swelling, locking, instability or pain that does not improve should be assessed rather than trained through.
For most people, gradual progression and appropriate recovery are more useful principles than trying to identify a single “perfect” running style or shoe. People with existing joint disease or significant previous injury may need individual advice from a physiotherapist or clinician.

