Many of the joints in our body are called ‘synovial’ joints, meaning they are filled with a smooth lubricating fluid (synovial fluid) and lined with cartilage on the ends of the bones that make up the joint. This ensures the joint can move freely and with minimal friction, and the cartilage helps to protect the underlying bone.
Osteoarthritis involves changes to the cartilage (as well as the underlying bone), and is associated with various factors including age, physical activity, and mechanical stress.1
What is Cartilage?
Cartilage is a unique tissue as it doesn’t have any blood supply. It gets its nutrients directly from the surrounding joint fluid through a process called imbibition – and getting these nutrients is critical for cartilage to stay healthy and repair itself.
Think of a sponge; each time you squash it (load it), the surrounding fluid moves in and out of the sponge. Cartilage is much firmer than a sponge and doesn’t squash down very much, but it gets its nutrients in the same way.
Excessive mechanical stress on cartilage may exceed its ability to recover and repair itself. This can include increased body weight and excessive exercise (especially with inadequate rest).1
So, what can you do to look after your cartilage?
Most importantly, regularly and appropriately loading cartilage seems to be important for cartilage health.2 That means - you guessed it - exercise!
If appropriate, losing weight can help reduce the overall mechanical stress on the cartilage.
If you are exercising frequently, ensuring you have adequate rest is important to allow your body to recover and repair.
What does regular and appropriate exercise for cartilage look like?
Well, it can take many forms and depends on the individual. What types of exercise and how much will depend on any pain you may have, which joints are affected, and your fitness levels. A qualified health professional can help guide you with this. Ideally, choose types of exercise that you are more likely to do regularly. Even something as simple as walking results in regular low to moderate loading to the joints in your legs and spine.
What is the take home message?
Whether you already have osteoarthritis or not, appropriate exercise can be helpful to stimulate cartilage health and repair. Osteoarthritis can also be painful for some people, and appropriate exercise is a great way to decrease pain too.3
Regards, Dr Sasha A.
O’Neill TW, McCabe PS, McBeth J. Update on the epidemiology, risk factors and disease outcomes of osteoarthritis. Best Practice & Research Clinical Rheumatology. 2018;32(2):312-26. doi: 10.1016/j.berh.2018.10.007.
Bricca A, Juhl CB, Grodzinsky AJ, Roos EM. Impact of a daily exercise dose on knee joint cartilage - a systematic review and meta-analysis of randomized controlled trials in healthy animals. Osteoarthritis and Cartilage. 2017;25(8):1223-1237. doi:10.1016/j.joca.2017.03.009
Moseng T, Dagfinrud H, Smedslund G, Osteras N. The importance of dose in land-based supervised exercise for people with hip osteoarthritis. A systematic review and meta-analysis. Osteoarthritis and Cartilage. 2017;25(10):1563-76. doi: 10.1016/j.joca.2017.06.004