Last reviewed: September 29, 2026

A little, and mostly in the first few months.

Exercising before surgery, often called prehabilitation, means strengthening and movement exercises in the weeks before a knee replacement, done with a therapist or at home.

Pooled reviews of trials find that people who exercise beforehand tend to have somewhat better function, less pain and stronger thigh muscles in the first weeks to three months after surgery. Some reviews also found a shorter hospital stay and fewer complications. By six months to a year, most reviews find little or no difference from people who did no program, though one found a small benefit that lasted longer. The trials are mostly small and tested very different programs, and the evidence is rated low to moderate.

Whether some people gain more, such as those who are frail, weak, heavier, or held back by pain, has been tested only in small trials, and the results are inconclusive. No type of program has been shown to beat another, and programs done at home have worked at least as well as those at a clinic.

Guidelines differ. The American physical therapy guideline and British guidance recommend exercise or exercise advice before surgery. The American Academy of Orthopaedic Surgeons guideline on knee surgery makes no recommendation either way. A guideline from rheumatologists and hip and knee surgeons says that once other treatments have stopped working, surgery should not be put off for a trial of physical therapy.

In general:

  • Exercising before surgery may make the first months easier.
  • It has not been shown to change how the knee does a year later.
  • It is not a reason to delay a surgery that has already been decided on.
  • Ask your surgeon or physical therapist which exercises suit your knee before surgery.

Drafted with AI assistance from published sources, reviewed and edited by Babak Sheikh, MD.

Sources:

This is general information about what published research shows. It is not medical advice and it is not about your situation. Reading it does not create a doctor-patient relationship with me. I am a retired orthopedic surgeon and I do not see patients. Talk with your own doctor before changing anything about your care. If something feels suddenly or seriously wrong, get medical care promptly rather than waiting.

This page is provided as is. I make no guarantee that it is accurate, complete or current, and medical evidence changes. Use of it is at your own risk.

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