A big study in The BMJ found that aerobic activities—like walking, cycling, and swimming—work best for people with knee osteoarthritis. These moves lowered pain, helped people move better, and made life feel better overall.
Other exercises can still help, but they should be added to aerobic work, not replace it.
What Causes Knee Osteoarthritis?
Osteoarthritis happens when the cartilage that cushions the ends of bones wears away. The knee joint then hurts, swells, and becomes stiff. Almost one‑third of adults over 45 show signs of knee osteoarthritis on X‑rays, and about half of them have strong symptoms.
What the Researchers Did
Scientists looked at 217 randomized trials done between 1990 and 2024. The trials involved 15,684 people and compared many types of exercise—such as aerobic, flexibility, strength, mind‑body, neuromotor, and mixed programs—with doing nothing or usual care.
How They Measured Success
They focused on four things that matter most to patients: pain level, ability to do daily activities, walking speed, and overall quality of life. Results were checked after 4 weeks (short term), 12 weeks (mid term), and 24 weeks (long term).
Aerobic Exercise Wins
Across all time points, aerobic exercise was the top performer. Moderate‑certainty evidence showed it lowered pain in the short and mid terms, improved daily function at every check‑in, and helped walking and quality of life in the short and mid terms.
Other types of exercise also helped. Mind‑body activities (like yoga) seemed to boost short‑term function, neuromotor training helped short‑term walking, and strength or mixed programs helped mid‑term function.
Is Exercise Safe?
None of the exercise groups had more side‑effects than the control groups. This means exercise is a safe option for most people with knee osteoarthritis.
Take‑Away for Doctors and Patients
Even though some study details were missing—like long‑term data for every exercise—the review is one of the most complete looks at this topic. It suggests that doctors should first recommend aerobic activity when they want to cut pain and improve knee function. If a person cannot do aerobic moves, other structured activities can still be useful.