Aerobic Exercise Outpaced Other Workout Types for Knee Osteoarthritis

CATEGORY: MOBILITY, BONES & JOINTS

Exercise eases a painful knee. Which kind eases it most has never had a clear answer, and the largest comparison yet assembled names a front-runner. Across 217 randomized trials covering 15,684 people with knee osteoarthritis, aerobic exercise came out as the type most likely to reduce pain and improve day-to-day function, on moderate-certainty evidence.¹ Aerobic here means brisk walking, cycling, swimming and other steady, rhythmic movement. Nearly every kind of exercise helped; the ranking is about which helped most.

Ranking Six Families of Movement Without Head-to-Head Trials

Researchers pooled 217 clinical trials published between 1990 and 2024. Every one had allocated people with knee osteoarthritis at random to an exercise program or to a comparison group. The team then applied network meta-analysis, a technique that links trials through their shared comparison groups so that exercise types can be ranked even when no single trial pitted them against each other. Six categories went in: aerobic, strengthening, flexibility, neuromotor, mind-body and mixed. Pain, daily function, walking ability and quality of life were assessed at four, twelve and twenty-four weeks. Aerobic exercise finished with the highest probability of being the best option overall, with moderate-certainty evidence for pain relief at four and twelve weeks and for better function further out.¹

What Each of the Six Actually Involves

Aerobic exercise is sustained movement that raises heart rate and breathing: brisk walking, cycling, swimming, pool workouts. Strengthening works the muscles around the knee against resistance, such as a weight or a stretchy band. Flexibility work is stretching held through a comfortable range. Neuromotor training drills balance and coordination, standing on one leg or stepping in controlled patterns. Mind-body exercise pairs slow movement with focused breathing and attention, as in yoga and tai chi, a flowing sequence of gentle postures sometimes described as meditation in motion. Mixed programs blend several of these into one routine.

Why Rhythm May Suit a Worn Joint

In osteoarthritis the cartilage capping the ends of your bones, a smooth and slippery cushion, gradually thins. The joint turns stiff, sometimes swollen, often painful. Cartilage has no blood supply of its own. It behaves like a sponge, drawing in nutrient-rich joint fluid when pressure eases and wringing out waste when pressure returns. A walk, a ride or a swim delivers thousands of those gentle squeeze-and-release cycles without sharp spikes of strain, which may be part of why steady movement served painful knees so well. Regular aerobic work also builds stamina and supports a healthy weight, and both lighten the load a knee carries.

The Specialists, and the Caveats the Authors Flag

The other five categories were far from useless. Mind-body exercise produced large short-term gains in function, strengthening and mixed programs improved function at twelve weeks, neuromotor training stood out for short-term walking ability, and flexibility work may modestly ease pain, though the certainty there was low.¹ Safety reporting was thin. Only about one trial in five tracked it, and no exercise type produced more adverse events than its comparison group. The authors note that most comparisons between types were indirect, that data past twenty-four weeks are scarce, and that small early studies can exaggerate short-term effects. An earlier network meta-analysis of 103 trials in knee and hip osteoarthritis ranked aerobic and mind-body exercise highest for pain relief, so this result lands on mapped ground.²

Key Takeaways

• Across 217 randomized trials and 15,684 people with knee osteoarthritis, aerobic exercise had the highest probability of being the most effective type for pain and function, on moderate-certainty evidence.
• Other types had specialties: mind-body for short-term function, strengthening and mixed programs for function at twelve weeks, balance-and-coordination training for walking ability.
• No exercise type caused more adverse events than its comparison group, though only about one trial in five reported on safety at all.
• Most comparisons were indirect and long-term data are limited, so the rankings read as probabilities across supervised, structured programs rather than guarantees.

References

1. Yan L, Li D, Xing D, et al. Comparative efficacy and safety of exercise modalities in knee osteoarthritis: systematic review and network meta-analysis. BMJ. 2025;391:e085242. link
2. Goh SL, Persson MSM, Stocks J, et al. Relative efficacy of different exercises for pain, function, performance and quality of life in knee and hip osteoarthritis: systematic review and network meta-analysis. Sports Med. 2019;49(5):743–761. link