Have you ever heard someone say they don’t exercise because it’s bad for their knees? Many people are of the belief that high impact exercise increases their risk for knee problems, especially osteoarthritis of the knee. It’s true that people who played certain types of sports involving torsional or twisting movements of the knees or who have a history of knee injuries are at greater risk for osteoarthritis of the knees, but that doesn’t necessarily mean that moderate amounts of high impact exercise is bad for your knees. In fact, there’s some evidence that it may protect against knee osteoarthritis.
High Impact Exercise and Knee Osteoarthritis: Is There a Link?
A study published in the journal Rheumatology addressed this issue. Researchers looked at the cumulative number of hours over 800 men and women presenting for knee surgery for osteoarthritis had participated in over their lifetime. Not only did moderate amounts of exercise not increase their risk for knee osteoarthritis, it had protective benefits. Men and women who had exercised regularly over their lifetime were less likely to be diagnosed with severe knee osteoarthritis compared those who were more sedentary.
Other studies also show moderate amounts of exercise and recreational sports protect against osteoarthritis of the knees. One study found that female physical education teachers who were physically active on a regular basis over many years had a lower risk of knee osteoarthritis, while another study showed people who walk regularly are less likely to suffer from painful knees due to osteoarthritis.
Even runners who run recreationally on hard pavement don’t seem to be at higher risk than the general population based on the results of some research. A study published in the Annals of Rheumatologic Disease found that recreational runners had no increased risk of osteoarthritis.
A twenty-year study conducted by Stanford University on distance runners found that runners’ knees were healthier and less arthritic than the control group that didn’t run on a regular basis
A study by Skeletal Radiology on Marathon runners over a ten year period found no new knee damage and concluded that running might even be beneficial to knee joints. As with most things, moderation is key.
Another study published in the Official Journal of the American College of Sports Medicine looked at changes in knee anatomy in more than 10,000 people who played sports recreationally and competitively using MRI imaging. Although they found a greater incidence of bone spurs in those who had exercised regularly, there was no narrowing of the joint space to indicate significant osteoarthritis. In fact, participants who had exercised had less cartilage breakdown than those who were more sedentary. This again suggests that exercise may help to preserve knee cartilage.
How Exercise Improves Knee Health
One way exercise improves knee health is by strengthening the quadriceps muscles. Strengthening the quads helps to prevent the progression of osteoarthritis of the knees and reduces pain in those who have it. According to research published in the World Journal of Orthopedics, both high and low-intensity aerobic exercise improves knee pain and functionality in people with osteoarthritis. Resistance training does too by strengthening the quadriceps muscles. Research shows that women with stronger quads are less likely to develop osteoarthritis of the knees. Exercise seems to not only reduce the risk of osteoarthritis – it treats the symptoms.
Another way regular exercise protects your knees is by reducing your risk for obesity. Obesity is a major risk factor for osteoarthritis of the knees. Maintaining a normal BMI definitely works in your favor when it comes to the health of your knees.
It’s also believed by some doctors that in the same way, high impact exercise increases bone and muscle mass it may also help to increase cartilage strength and prevent cartilage loss with age.
The Bottom Line?
High Impact exercise may not be as bad for knees as previously thought and may even be good for your knees. In fact, regular exercise may offer some protection against osteoarthritis by strengthening knee cartilage, the quadriceps muscles and by helping with weight control. Though high impact exercise is often blamed for causing knee problems there are other factors that are more likely to cause osteoarthritis. If you have osteoarthritis, talk to your doctor before doing high-impact exercise but high impact exercise in moderation appears to be beneficial for those that don’t suffer from severe osteoarthritis.
Rheumatology. Volume 40, Issue 4. Pages 432-437. (2001)
Clin. Orthop. 261: 242-6.
Ann. Rheum. Dis. 55: 692-4. (1996)
Official Journal of the American College of Sports Medicine. “What Is the Effect of Physical Activity on the Knee Joint? A Systematic Review”
World J. Orthop. May 18: 2(5): 37-42.
Arthritis Today. “Exercises to Strengthen the Knee and Relieve Pain”
Arthritis Today. “Strong Quadriceps Protect Women’s Knees from Pain”