If pain in your joints doesn’t limit your physical activity, exercise is a good way to improve your wellbeing when you have osteoarthritis (OA). This is a well-established fact of wellness, but now two physicians in Sweden have done a study, reported in the medical journal Arthritis & Rheumatism, in which they discovered a possible mechanism for the beneficial effects of exercise in preventing deterioration of your knee joint.
Loss of cartilage is one of the main structural changes in OA, but moderate exercise seems to build up that cartilage. 45 middle-aged people at risk of developing OA, who had undergone a partial removal of their medial meniscus (a knee cartilage) 3-5 years earlier, participated in the study. The volunteers either spent four months doing a one-hour programme of supervised exercise, 3 times a week, or else they were in a control group that received no treatment. At the beginning of the study, the researchers did an MRI of the patients’ knee, which estimated the elastic properties (known as glycosaminoglycan or GAG) of their cartilage.
Of all the volunteers, 30 had this special MRI before and after the study period, 16 of whom were in the exercise group. These participants had a significantly improved level of GAG in their cartilage, while the 14 subjects in the no-treatment group showed deterioration in their GAG level. The researchers also discovered that there was a correlation between the amount of exercise the subjects did and the amount their GAG content improved. In other words, the more they exercised, the greater their increase in GAG. The exercise group also exhibited improvements in pain, quality-of-life, and physical performance scores.
According to one of the study’s authors, the change seen in GAG content with exercise indicates that ‘human cartilage responds to physiological loading in a way similar to that exhibited by muscle and bone.’ This means that, at least in the short-term, improvement in the quality of your cartilage is the reason that exercise improves many of the symptoms of osteoarthritis. Therefore, if you are at risk of developing OA, or you want to reduce its symptoms, a structured exercise programme can help.