It is a concern that non-runners and runners share. Does running increase your risk of osteoarthritis? Once you have arthritis in your hip and knee, does it mean you have to stop running?
The research is a bit conflicted when it comes to the contribution of running to osteoarthritis. Researching this is quite challenging when you think about it. We all have various genetic factors that can contribute to arthritis or not, then we all have previously engaged in certain activities that may or may not have contributed to arthritis, plus our previous injuries to the hip and knee certainly impact whether we will get osteoarthritis, and how soon this diagnosis will appear in life. Now compare this to a sedentary person’s knee and hip. Just living a sedentary lifestyle involving prolonged sitting, increased body mass index, and poor nutrition can all contribute to the onset of osteoarthritis. So, is running the reason for your osteoarthritis diagnosis? Or was it genetically programmed to happen anyway? Once diagnosed with osteoarthritis, should you modify your running program?
Let’s start with the activities that have been singled out in research as those contributing to increased risk of knee osteoarthritis: elite level distance running, soccer and football participants, competitive weight lifting, and wrestling. However, the overall incidence of knee osteoarthritis was not significantly higher in athletic participants versus non-participants. Another study found a 3% decrease in the volume of knee cartilage after a 12 week running program, and a 1.5% decrease in cartilage after a 12 week cycling program, whereas there was no decline in the amount of knee cartilage in those participating in power walking, swimming, and non-exercising control subjects.
Yet other research says that the fact that the foot contacts the ground for such a brief time in runners mitigates the increased stresses from the force of the impact of the running foot versus the stress occurring in walkers as their foot hits the ground. Another researcher reported that over time, runners have a lower risk of hip and knee replacement than walkers. This finding was related to the lower body mass index of the running population compared to walkers and non-athletic participants. So while running increases the wear and tear on cartilage over time, especially with very high volume/duration running training programs, because runners have less body mass, the overall risk of osteoarthritis leading to joint replacement is actually less or equal to other active and in-active adults.
So what is the final answer on running and osteoarthritis? Because runners have a lower body mass index compared to walking and sedentary cohorts, the overall increased risk of progression of osteoarthritis requring joint replacement is low. The high physical fitness level of runners is also protective against diabetes, obesity, heart disease, stroke, hypertension, dementia, and depression. In fact, there is actual research that runners have a lower mortality rate than non-runners, adding on average 3 years to their lifespan. So despite the potentially detrimental effect of running on hip and knee cartilage volume, the overall benefits of running appear to outweigh the risk.
What about running after having a total knee or hip arthroplasty? The jury is still fairly undecided here. Research has found that patients with a unilateral versus full knee joint replacement have a better chance at returning to higher, more forceful levels of activity for sports such as running. Also, do metal or plastic filings that appear after such compressive forces are applied with higher level athletic activities mean a loss of the implant, loosening, or potential dislocation? While early reports show some promise for return to higher activity levels with the advances in hip and knee hardware and implant components, without long term research there is no guarantee that increased activity levels will not reduce the overall life of the implant compared to participation in lower impact activities such as walking, swimming, biking, golf, and bowling.
If you have been recently diagnosed with hip or knee arthritis, there are some strategies to prolong your running career without contributing to progression of osteoarthritis. First, add some cross training that includes lower impact activities such as swimming and biking. Next, consider changing your goals. Elite level runners typically run more than 60 miles per week. Consider cutting back your mileage to reduce cartilage loss. Also, work with your physical therapist or athletic trainer to make sure your running mechanics are clean, without hip internal rotation and knees falling in, which will increase the wear and tear to specific areas of your joints. A rehabilitation professional will also work on your hip and knee joint mobility if needed with specific techniques, as well as checking your strength. Research shows that improving hip strength and movement biomechanics, along with foot orthotics, and changing running gait patterns all can assist in off-loading an arthritic joint while still allowing participation in high impact sports.
In conclusion, running IS the fountain of youth, as is any kind of regular, challenging physical exercise, so get out there and add a few high quality years to your lifespan! Be smart about how you plan your work-out routine, respecting old injuries and newly diagnosed arthritis, getting extra help from rehab professionals, and you can successfully participate in high level activities like running for years to come!