Artificial knees have helped seniors treat osteoarthritis and other similar conditions, but new research suggests it’s important to remain active after the procedure. A study recently published in the journal Arthritis Care & Research found that knee replacement surgery is closely tied to weight gain, Reuters reports.

The research analyzed the medical records of nearly 1,000 patients from the Mayo Clinic. The team found that 30 percent of those who had the procedure gained approximately 5 percent of their body weight in the five years after surgery. Experts hope the findings are a clear message to patients and senior care providers to place an emphasis on staying active after surgery.

“We need to encourage patients to take advantage of their ability to function better and get them to take on a more active lifestyle,” Joseph Zeni, a physical therapy professor at the University of Delaware, told Reuters.

The weeks after knee replacement surgery are crucial, and it’s up to both patients and those providing home care to ensure the treatment is as successful as possible. Surgeons will offer strict orders on what to follow in terms of diet, while physical therapists will provide advice on exercises. According to the Mayo Clinic, the therapy usually starts off with a graduated walking program before resuming normal household activities. Additionally, leg strengthening exercises performed several times a day can avoid the common weight gain and help seniors quickly get back to normal.