Can Exercise Cause Knee Arthritis?

The saying “Less is more” may be true for exercise, at least in one respect. Recently, a study of 236 adults aged 45–55 discovered that those who were more physically active throughout their lives were more likely to experience knee arthritis. The study was
presented at the annual meeting of the Radiological Society of North America. The participants included men and women of “healthy weight” whose activity levels were classified as low, middle or high. The researchers studied MRI scans of each individual’s knees to determine joint integrity. Approximately 93% of those in
the high-activity group presented with knee cartilage damage,
as opposed to 60% in the low-
activity group. Further, knee damage in the high-activity group was three times more severe than in the low-activity group. No information was provided on variables such as type of activity performed, footwear used or the subjects’ posture and alignment.

While such a study may cause people to become more wary
of exercise, Katy Bowman, MS,
director of the Restorative Exercise Institute in Ventura, California, believes this is an
opportunity for fitness professionals to emphasize quality of exercise over quantity. “The most important aspect of this study is that more exercise is not necessarily better,” says Bowman. It also helps to outline elements of training that may be missing from an exerciser’s regular routine. “We tend to be great at cardiovascular and strength training, but some have a tendency to overlook flexibility.” Specifically with regard to knee joint degeneration, Bowman suggests assessing lower-leg flexibility. “Inflexible calf muscles can lead to excess tension in the knee joint,” she says. To overcome strength and flexibility deficits, Bowman first urges fitness professionals to become more acquainted with stretching science through research and continuing education. She advocates that fitness professionals design programs that equally balance cardiovascular, strength and flexibility training. “Adding stretching to a personal training program can enhance a client’s success in both increasing metabolism and increasing muscle strength. Both muscle function and a muscle’s metabolism are determined by muscle length. Stretching increases physiological performance by restoring muscle to its optimal length
and can also reduce anatomical degradation by decreasing compression within the joints.”