Walking, cycling and swimming came out on top for easing chronic knee pain in the most comprehensive comparison to date. The network meta-analysis pooled 217 randomized trials with 15,684 participants and was published in the BMJ in October 2025.
Aerobic exercise ranked first for pain relief, physical function, walking ability and quality of life, ahead of strength training, flexibility work, mind-body approaches such as tai chi and yoga, neuromotor drills and mixed programs. It also matched the safety of every other option.
What counts as aerobic here
The reviewers defined aerobic exercise as structured, rhythmic activity that raises the heart rate, such as walking, cycling or swimming. These are the same low-impact staples that most people with knee arthritis can fit into a regular week without a gym membership.
The trials tested a range of doses across short-term (about 4 weeks), mid-term (12 weeks) and long-term (24 weeks) follow-up. No single prescription came out of the analysis, but broader public health guidance from the CDC points adults with arthritis toward at least 150 minutes a week of moderate-intensity aerobic activity, plus muscle-strengthening on two days.
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How big the effect was
Aerobic exercise reduced pain with a standardized mean difference of −1.10 in the short term and −1.19 at mid-term, both with moderate-certainty evidence. Function improved by 1.78 at mid-term, and short-term quality of life by 1.53. In plain terms, these are large effects for a nondrug intervention, though the estimates carry the usual caveats of pooled trial data.
Across the ranking metric the reviewers used, aerobic exercise scored 0.72, which they describe as showing "its superior overall efficacy compared with other interventions." Strengthening, flexibility and mind-body work still helped, and the authors say alternative forms of structured activity remain useful when aerobic exercise is not practical.
Why movement, not rest, helps aching knees
Regular loading appears to nourish cartilage and joint fluid, and moderate activity tends to lower low-grade inflammation and strengthen the muscles that stabilize the knee. Sitting still, by contrast, tends to stiffen the joint and weaken the very muscles that protect it.
Crucially, none of the exercise types in the review produced more adverse events than the control groups. That safety signal matters for anyone who has been told to take it easy. The authors recommend aerobic exercise as a first-line intervention for knee osteoarthritis, particularly when the goal is to improve function and cut pain.
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Knee osteoarthritis is common. According to a BMJ press release accompanying the study, nearly 30 percent of people over 45 show signs of it on X-rays. Symptoms should still be discussed with a clinician, especially before starting a new exercise routine or if a joint is swollen, unstable or waking someone at night.
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This article is made and published by Jesper Bengtson, who may have used AI in the preparation.