In the study, researchers had adults walk or run on a moving platform that captured data on the amount of force, or load, each step had with the ground over a set distance. Results showed that the force exerted on the knees while running was as much as 3 times higher than while walking, but this was offset by the time runners spent in the air and the length of their stride.
While the extra load caused by running has long been a concern, especially for bigger guys who are pounding the pavement, it has never been shown to increase the risk of knee osteoarthritis—the irreversible wearing away of the knee cartilage—for runners, says Ross Miller, Ph.D. and study author.
The studies show that regular runners actually experience less long-term damage to their knee joints than non-runners. Even though running generates more force (and burden on your knees) than walking, you pound the pavement less frequently when running because your strides are longer. So, as long as your knees are healthy to begin with, running doesn’t significantly increase your chances of developing arthritis.
In fact, regular runners actually experienced less knee pain over time. This is partially because running keeps you super fit (meaning you are likely to carry less excess weight). And a regular running regimen typically leads to better overall muscle strength.