“If you have osteoarthritis, exercise is one of the most effective treatments we know,” says David Felson, professor of medicine and epidemiology at the Boston University School of Medicine.
It’s not that exercise can cure or slow the progression of osteoarthritis. “Its benefit is to alleviate pain and increase range of motion, not necessarily to make the structure of the joint better,” notes Felson.
How can exercise curb pain? “It can lower overall inflammation,” says Allison Bailey, a physician specializing in physical medicine in Cambridge, Massachusetts.
Inactivity leads to more trouble. “If you don’t keep using an arthritic knee or hip, you can lose flexibility,” says Felson. “Doing weight-bearing exercises keeps muscles strong and flexible, which reduces further injury to the joints.”
On the other hand, adds Felson, “doing aggressive physical activity when you’ve injured a joint may not be wise,” because you risk damaging the joint even further.
Here’s what Bailey and other experts recommend:
STRENGTH TRAINING. Strong muscles absorb weight, provide stability, and help the joints move the way they’re designed to. Among 95 older adults with mild to moderate arthritis of the knee, those who were told to do strengthening exercises for 12 weeks reported less knee pain and climbed stairs faster than those who weren’t told to exercise.
Bailey gives patients with mild to moderate knee and hip osteoarthritis some simple at-home exercises.
“I usually have patients do strengthening every other day,” she says. “The overall goal is to strengthen the quadriceps—the muscles in the front of the thigh—and the gluteal muscles in the buttocks.”
Bailey has her patients start with gentle stretching. “Then they do two sets of each exercise, with 10 to 12 repetitions each.”
“You can also strengthen the muscles without doing weight-bearing activities,” notes Moskowitz. For example, if lifting weights hurts, try Bailey’s leg extension exercise without ankle weights.
If an exercise hurts, don’t do it, says Felson. “Ask your doctor about exercises that don’t cause you pain.”
AEROBIC EXERCISE. Exercises like walking briskly, jogging, biking, and swimming increase blood flow to cartilage, which gives it the nutrients it needs to stay healthy.
What’s more, “cardiovascular exercises help reduce the body’s sensitivity to pain signals,” explains Bailey. For instance, people who cycled for 25 minutes felt less pain when researchers applied uncomfortable pressure to one of their fingers after they exercised than before they exercised.
“Ideally, cardio should be done daily, or at least six days a week,” says Bailey.
In 2012, a group of Canadian arthritis experts concluded that walking for 30 to 50 minutes at least three days a week relieved osteoarthritis knee pain. The longest trial they reviewed lasted only three months, though.
Some people with arthritis prefer swimming because it puts less pressure on the joints. “If you’re afraid to start moving,” says Bailey, “you may want to consider using aquatic therapies as a bridge to land-based activities.”
While water exercise relieved pain from knee and hip osteoarthritis in four trials, it didn’t improve walking ability or stiffness.
TAI CHI. The classic Chinese martial art involves a series of slow and gentle movements that combine balance with weight-shifting poses.
“I recommend tai chi to a lot of my patients, especially because you can do it indoors in the winter months,” says Bailey.
In a recent meta-analysis of seven small trials, people with arthritis of the knee or hip who practiced tai chi for 40 to 60 minutes a day for at least 12 weeks reported less pain and stiffness and improved function in their joints than similar people who engaged in a non-physical activity like playing bingo.
But only two of the studies included people with arthritis of the hip, so it’s not clear whether tai chi only helps the knee.
“An alternative is gentle daily stretching,” says Bailey. (No good studies have looked at whether stretching or yoga can help relieve arthritis pain.)
Sources: Osteoarthritis Cartilage 18: 621, 2010; J. Rehabil. Res. Dev. 42: 183, 2005; Arch. Phys. Med. Rehabil. 93: 1269, 2012; Cochrane Database Syst. Rev. 2007. CD005523; PLoS One 2013. doi:10.1371/journal.pone.0061672.