The Truth About Knee Osteoarthritis and Exercise: Why Movement is Key to Joint Health

Despite the well-documented benefits of exercise for osteoarthritis (OA). A common misconception persists—that exercise may be harmful to joints. However current research supports the opposite, showing that physical activity is not only safe but beneficial for joint health.

What is Knee Osteoarthritis?

Knee osteoarthritis (OA) is a degenerative joint disease marked by the structural breakdown of cartilage and surrounding joint tissues

Traditionally, muscle weakness in OA has been attributed to muscle atrophy due to joint pain. However, newer findings suggest that age-related muscle loss may also be a contributing factor to OA development. This shift in understanding raises the question: can exercise not only prevent but also effectively treat OA symptoms?

Evidence

Research increasingly supports exercise as a beneficial intervention for knee OA. A systematic review of 15 studies comparing 7,000 runners with 7,000 non-runners found no significant association between running and the development of knee OA (Dhillon et al., 2023). In fact, muscles play a vital role in joint biomechanics by producing movement, absorbing load, and providing dynamic stability. These functions are crucial in the joint adaptation and degeneration process seen in OA (Valderrabano & Steiger, 2011).

Exercise programs—both aerobic and strengthening—have demonstrated clear improvements in OA symptoms. Patients have reported decreased pain and enhanced muscle function (Valderrabano & Steiger, 2011). These findings led researchers to conclude that there is “overwhelming” evidence that light to moderate PA does not cause or accelerate OA. Instead, PA may protect against knee degeneration and should be recommended to all patients for its broad health benefits (Esser & Bailey, 2011).

Recommendations

The Osteoarthritis Research Society International (OARSI) recommends exercise as a primary intervention for improving pain and function in OA. Patients can benefit from structured activity goals—such as walking 10,000 steps per day (Esser & Bailey, 2011; Tudor-Locke et al., 2011). For those unable to join formal exercise programs, maintaining an active lifestyle through walking, gardening, biking, or similar daily activities remains crucial (Valderrabano & Steiger, 2011).

Running and Joint Health

Contrary to common belief, running can actually improve joint health when managed appropriately. Studies show that the cartilage of runners is often stronger than that of non-runners. This is partly due to the body adapting to the load sustained during running—when given adequate recovery time, these stresses stimulate repair and strengthen joint tissues.

However, recovery is key. Those with OA should respect longer recovery periods and may benefit from incorporating non-impact activities like cycling to aid joint recovery. Finding the right balance—or "sweet spot"—in training volume is essential. If current running habits are not aggravating symptoms, there may be no need to alter them.

Optimizing Running for OA

To further reduce joint strain and support knee health:

• Prioritize strength training, especially targeting lower limb musculature.

• Run on softer surfaces (e.g., grass or trails) instead of hard tarmac.

• Experiment with different shoe types—cushioned or minimalist shoes may redistribute force, but transitions should be gradual.

• Avoid overstriding, which increases "braking forces" that transfer more stress through the joints.

Consider reducing weekly mileage if needed, while focusing on consistent recovery.

If you found this post helpful. I would be more than happy to schedule an appointment to come see how you can start to Reclaim your exercise. Book Here.

Happy Running :)

Knee osteoarthritis and exercise