You’ve probably heard it before. “Running is bad for your joints”. “It will wreck your knees”. “You’ll need a knee replacement in 20 years”. Most of these comments usually come from non-runners. Running is a natural action for humans, yet many people who don’t do it seem convinced that this highly beneficial exercise choice that burns many calories, improves heart health and reduces disease risk is bad for you. So could it be harmful to joint health?
It’s good news. A 20-year study conducted by Professor James Fries of Stanford University in California found that runners from the study (now in their 70s) revealed that those who run consistently could expect to have less arthritis than non-runners when they get older. It also showed that runners have a lower risk of osteoarthritis and hip replacements.
A 2014 study conducted by Dr Grace Hsiao-Wei Lo, Assistant Professor of Medicine at Baylor College of Medicine, found that running at any stage of life doesn’t increase a person’s risk of osteoarthritis of the knee. In fact, it may even help to ward off the condition.
The findings of the study, presented at the American College of Rheumatology Annual Meeting in Boston, looked at over 2,600 participants, giving them knee x-rays, assessments and surveys. Researchers concluded that runners had a lower prevalence of knee pain than non-runners, regardless of their age.
Born to run
The experts are not surprised. “Our bodies are designed to run,” says Professor John Brewer, Head of its School of Sport, Health and Applied Science (SHAS) at St Mary’s University (stmarys.ac.uk). “In the past we had to run to catch food or avoid being the food of a predator, so running is a natural form of human locomotion.”
Samantha Moss is Lead Physiotherapist for Nuffield Health (nuffieldhealth.com), and has been monitoring various studies. “There is currently no good evidence that running alone causes osteoarthritis,” she says. “There is some evidence that extreme levels of running, that those who run marathons and ultra marathons have a higher incidence of osteoarthritis, but there have been no good research trials into this to confirm a link either way.”
Moss adds: “A review of running and risk to joint health (published on the website PubMed.gov in the US) found no evidence that moderate levels of running in itself was detrimental. In fact, we can reduce the risk of osteoarthritis by maintaining a healthy weight, building muscle, flexibility and balance, which can all be achieved through activities such as running.”
Better bone health
Some loading of the joints is actually good for us. “Running can improve our joint and bone health, especially if we manage the volume and frequency of our runs,” says physiotherapist Stuart Mailer from Kensington Physio & Sports Medicine (kenphysio.com). “When we run, there is a high stress and load going through our joints and bone tissue that can improve bone density, helping to prevent osteoporosis and osteoarthritis. The bone remodels itself frequently and adapts to the stress it is put through. Running can help our joint health so long as we are sensible with regards to volume and intensity.”
So why does it hurt?
If your running technique is poor, you have weak muscles or imbalances, the wrong shoes or you overdo your running volume, you may suffer. “Problems can arise when an individual has a biomechanical issue that puts extra stress on a particular joint or when they do too much and refuse to listen to signals (like pain) telling them to rest or ease off,” says Brewer.
Unfortunately, carrying extra weight can exacerbate the problem. “Simple physics says that the greater the force through the joint surface, the greater the wear and tear, which is the essence of osteoarthritis,” says physiotherapist Mark Buckingham from Witty Pask & Buckingham (wpbphysio.co.uk). “The joint surface does not increase in size with an increase in weight, so therefore there is greater force on the same surface area. Hyaline cartilage is remarkable stuff but it can tolerate only so much and once it has gone, it’s gone – much like your teeth!”
“When each foot hits the ground with each stride, a force equivalent to three times a runner’s body weight is transmitted through the legs and lower limbs,” says Brewer. “When a runner is overweight, this is going to greatly increase forces and stresses transmitted into and through the knee joint, increasing wear and tear and the risk of problems.”
Experts advise trying to lose weight if you are significantly overweight as it can increase injury risk in general. “Being overweight or having previous injuries are some of the risk factors for developing osteoarthritis in the knees, hips and lower back,” says Moss. “Studies since the 1980s have demonstrated this risk factor repeatedly. However, being active and losing weight removes load through the joints and so reduces risk.”
If you are excessively overweight, you may choose to lose some weight first by sticking to low-impact exercise, such as cycling, swimming or using the cross-trainer. However, don’t be put off entirely. “Being slightly overweight and running 15-20 miles a week is likely to create fewer problems than being 10 kilos overweight and running 70 miles a week,” says Brewer. He also points out that if you take up running for the first time and you are overweight, you’re not likely to be doing long distances, which offers some protection from injury risk. “When someone who is significantly overweight runs, they are unlikely to have a higher level of fitness that can sustain running for long, or at a high speed,” says Brewer. “Therefore the potential for joint damage is greatly reduced, and consequently people who are significantly overweight should be encouraged to run at a tolerable speed as a means of burning calories and aiding weight loss.”
Often the warnings about running ruining your knees come from older relatives, who assume that a family history of arthritis means you’re guaranteed to have problems. Is that really the case?
If a first-degree relative had a knee replacement early on, then you may be more predisposed to joint issues in future. “A family history of osteoarthritis is an indicator that you are more likely to suffer yourself,” says Buckingham. “There seems to be a variance in the quality of cartilage between us. Some have very resilient stuff, which seems to put up with anything. Others have poor cartilage, which wears more easily regardless of how much you stress it with impact.”
Moderation is key, but don’t be deterred. “Simply put, if you have decent cartilage and no family history, then you can get away with a lot more,” says Buckingham. “If you have osteoarthritis in the genes then you are likely to suffer, and sadly, if you run and stress the cartilage, then you are much more likely to suffer early on.”
However, working on leg strength, ensuring your shoes are the right ones for you and having regular rest-days in between running sessions will all help. “I would never say avoid it completely,” says Brewer. “I think if you have a family history of osteoarthritis then running in moderation is still possible, but seeking medical advice first from an expert is an important first step. Start slowly, increase gradually and clearly, if there is a family history, it makes total sense to be cautious.”
Running may be part of your weekly training schedule but you could combine it low impact exercise to give your joints a break. “That includes cycling or swimming, both of which place less stress on the joints,” says Brewer.
If you want to do a longer race like a marathon and you have a family history of knee problems, then don’t be put off. Be sensible, train well, work with a physiotherapist to strengthen the muscles around the knees and rest up in between runs. “As long as you are sensible, I think it’s highly unlikely that they will increase their risk of arthritis or knee ops,” says Brewer. “Most will be fit as a result of their regular exercise and will have maintained a low body fat percentage, and these are important enhancers of quality of life as we get holder. Many hundreds of thousands of people run marathons and ultras each year, and they are not all queuing up for knee replacements afterwards.”