Arthritis can be crippling and painful. We can safely say that no one wants arthritis, however, many of us will get it anyway. Research in this area has been confusing. There has been a fair amount of research on exercise and arthritis with many finding an increased risk with exercise and other finding decreased risk. There are probably many factors involved and many reasons why one study produces on result and similar study does not. The type of exercise may be key. Common belief has been that running would lead to arthritis in the knees or hips. That particular belief seems to be incorrect. Running may in fact protect the knees and hips and prevent arthritis in these areas. There are a number of ways be which exercise may protect joints:
- Strengthening of cartilage and connective tissue
- Increased production of elasticity protective factors like cartilage proteoglycans
- Helping people maintain a healthy weight so that joints are less stressed on a daily basis.
The first two factors are important because thinned, inelastic tendons go hand in hand with osteoarthritis. Osteoarthritis is usually caused by injury or wear and tear rather and not an auto-immune process.
The National Runners Health Study Results
The National Runners Health Study is a study of about 60,000 runners and 40,000 walkers that began in 1998. 50,000 or these original volunteers completed a survey in 2006. A recent report using data from the National Runners Health Study found no increased risk of osteoarthritis or hip replacement among recreational runners. This included runners who completed multiple marathons and regularly exceeded recommended guidelines for exercise. In fact, the number of marathons run did not seem to have much to do with arthritis risk. Risk of arthritis and hip replacement was lowest in subjects that ran more than 8 miles a week.
People who walked also had less arthritis and hip replacements, but the benefit seemed to be greater for runners. The researchers calculated that about 1/3 to 1/2 of the decreased risk of arthritis was simply reduced body mass index (BMI) in people who run or walk.
Williams PT (2013). Effects of running and walking on osteoarthritis and hip replacement risk. Medicine and science in sports and exercise, 45 (7), 1292-7 PMID: 23377837