Research Summary
Pool Exercise vs Land Exercise for Knee Arthritis: Review of 9 Trials Finds No Clear Winner
Exercising in a pool was not consistently better than exercising on land for people with knee osteoarthritis, according to an updated review of 9 randomized trials. The systematic review was published in Healthcare in October 2026.
What was studied
Water exercise is often suggested for sore knees because the water supports body weight. Researchers from Portugal searched four databases for randomized controlled trials published between September 2018 and July 2025 that directly compared supervised aquatic exercise with land-based exercise in adults with knee osteoarthritis. They rated trial quality with the PEDro scale and the certainty of evidence with GRADE.
They included 9 trials enrolling 700 participants, 661 of whom contributed to the pool-versus-land comparison. Because the trials differed so much in patients, exercise content and dose, and outcome measures, the team summarized results without pooling them into a single number.
Key findings
- Pain differences on a visual analog scale ranged from about 0.3 to 1.8 points in favor of pool exercise, but it was often unclear whether these differences were large enough to matter to patients.
- Results for physical function and quality of life were inconsistent, and several comparisons showed no difference between groups.
- The certainty of evidence was mostly low or very low.
What it means for people with knee pain
Both kinds of exercise can be reasonable choices. The authors concluded that the type of exercise should be chosen based on your preferences, what you can access, and your health situation. If land exercise hurts too much or a pool is easy to reach, water exercise may help you stay active; if not, land-based exercise remains a solid option.
Limitations
The trials were varied and many were small, results were imprecise, and longer follow-up and better adherence tracking are needed. No meta-analysis was performed.
Frequently asked questions
- Is water exercise better than land exercise for knee arthritis?
- Not consistently. In this review of 9 trials, some pain results favored pool exercise, but the differences were generally small or uncertain, and function and quality of life results were inconsistent.
- Who might prefer pool exercise?
- The authors suggest choosing based on individual preferences, access and clinical situation. People who find land exercise too painful or who have easy pool access may find water exercise a good way to stay active.
- How strong is this evidence?
- The certainty of the evidence was mostly rated low or very low, and the trials were too different to combine statistically, so more well-designed trials are needed.
Sudden severe pain, swelling, or can't bear weight? Seek medical care promptly. In an emergency call 911.