Can too much exercise wear out your joints?
Do you have creaky knees or ankles? Is getting out of bed each morning a struggle? Do you grimace when faced with a set of stairs? Everyday movements can become a chore when the cartilage in your joints starts to break down, making them stiff and sore. Sore joints are the hallmark of osteoarthritis, and while it's more common in those over 40, plenty of people in their 20s and 30s have it too. Since it often strikes younger people who are active, you might well wonder if exercise itself could be to blame. But is this really the case? With every movement our limbs make, are we literally wearing our joints away? Sydney rheumatologist Patrick McNeil is quick to dispel this notion. The idea that our joints are like car tyres or light bulbs, with a limited number of uses before their lifetime expires, is simply untrue, he says. "I think it's a myth to make the general statement that exercise is bad for your joints or actually wears your joints out," Professor McNeil says. "There's no evidence for that." He says plenty of older people who have been active all their lives never develop osteoarthritis and it's only in some instances that exercise could be harmful to joints. What is arthritis?
Arthritis is a generalised term covering more than 100 medical conditions affecting the musculoskeletal system where two or more bones meet. There are many kinds of arthritis but osteoarthritis is the most common form, says Arthritis Australia.
Osteoarthritis, often (incorrectly) referred to as "wear and tear", affects the entire joint, including bone, muscle, ligaments and cartilage — the firm, slippery tissue that covers the ends of bones where they form a joint, helping the bones glide over each other. It is best thought of as a dynamic process: joints can repair themselves but in osteoarthritis, the repair processes are overwhelmed by destructive processes. This can happen for reasons related to genes, being overweight, injuries and the way a joint is used. When the alignment of a joint is incorrect — perhaps because of weakened muscles or because you were born with unusually shaped joints — movement of that joint might have some role in wearing cartilage away. "You could be born with cartilage that will last, no matter what you do to it, or you could be born with cartilage that's less durable," Professor McNeil says.
The processes leading to cartilage loss may be different in different parts of the body. Osteoarthritis of the hands, for instance, seems to have a very strong genetic basis and Professor McNeil says medical experts still don't understand all the triggers. "Exercise doesn't seem to be relevant at all to osteoarthritis of the hands," he says. "If use was a factor, you'd expect right-handed people to have more arthritis in their right hand than in their left, but that isn't the case." Impact of injuries on joints
An injury can affect the previously perfect alignment of a joint, as many footballers would agree. Sports that expose joints to extreme forces — like football — make injuries more likely and are known to raise the odds of joint trouble down the track.
Professor McNeil quoted Sydney University rheumatology professor David Hunter's findings that tears to the anterior cruciate ligament (ACL), a major ligament in the knee, carry a 70 per cent risk of osteoarthritis within 10 to 15 years. Even when the ligament is surgically repaired, the initial injury changes the stability of the knee permanently so that over time, it's more likely cartilage will break down. Some of the main sports associated with ACL injuries are the football codes, netball, basketball and skiing, according to Sports Medicine Australia. Fortunately, exercises that strengthen key muscles around joints can reduce the risk of ACL tears and other injuries that predispose a person to arthritis by as much as 60 per cent. Exercise unlikely to harm joints… unless there are signs suggesting otherwise
The bottom line is, the evidence so far doesn't suggest a strong connection between simple, repetitive use of a joint and the development of osteoarthritis. Professor McNeil says if your joints aren't bothered by the exercise you're doing, it's unlikely you're doing them harm. However, if you have already been diagnosed with joint damage, or have pain that suggests it, it's possible the wrong sort of exercise could make your arthritis worse. "If you have osteoarthritis in weight-bearing joints such as the hips, knees and lower spine, for instance, high-impact exercise like running can certainly aggravate symptoms," Professor McNeil says. "It's probable it might accelerate progression [of joint damage] although I think that's still an open question. "In those cases I'd probably recommend a lower-impact exercise, such as swimming or bike riding, that puts less stress on the affected joints."
Can exercise benefit arthritis?
Professor McNeil says exercise is actually one of the best treatments for (osteo)arthritis. "It's much better to be physically active than to hold back because of your joints," he says.
Cartilage is living tissue but it does not have arteries that deliver blood and therefore, relies on movement of the joint to create a pumping action that circulates fluid containing oxygen and nutrients. Exercise also decreases pain, helps maintain the mobility and flexibility of joints and improves muscle strength, which can help hold joints in their correct alignment and take pressure off sore areas. The other very important benefit of exercise is that it helps you maintain a healthy weight. Excess weight increases the risk of osteoarthritis by placing stress on joints and, of course, exercise is proven to have significant general health benefits for everyone — whether they've got existing joint troubles or not.
Article from ABC Life