Geschatte leestijd: 3 minutenRunners often hear that their hobby is bad for the knees. However, recent research suggests the opposite: running may actually be good for the knees.
Broscience and Running
The notion that running is bad for the knees seems to increasingly fall into the category of ‘broscience.’ The simple explanation for the supposed danger is that the high pressure on the knee joint leads to wear and tear (osteoarthritis). Sounds logical. To this day, many fitness instructors and personal trainers prefer to recommend other forms of cardio.
However, research has never been able to prove this. In 2013, an epidemiological study was conducted on the effects of running and walking. Nearly 75,000 runners and 15,000 walkers were followed for 5 to 7 years [1]. This was the largest study to date in this area. Runners were found to have no increased risk of osteoarthritis compared to walkers. Even regular marathon running did not increase the risk.
Weight, or more accurately, BMI, was found to play a significant role. A higher BMI was associated with a higher risk because it creates more pressure on the joints. An increase of 1 point in BMI meant a 5% higher risk of osteoarthritis. The fact that runners had, on average, a lower BMI largely explained the lower risk.
Whereas other exercise increased Osteoarthritis and hip replacement risk, running significantly reduced their risk due, in part, to running’s association with lower BMI.
P.T. Williams
Five years earlier, researchers from Austria also concluded that running has no negative effect on the knee joint [2]. However, their study was conducted on a small scale with only 7 runners. They used MRI to detect any damage. They also concluded that running posed no risk to the cartilage.
“Running is Good for the Knees”
The most recent research in this area goes further: running may actually have a protective effect [3].
American researchers from Brigham Young University looked at the direct effect of running. They used healthy runners as subjects who ran for half an hour. They were wheeled in on a wheelchair to minimize the effect of pre-test activities. Half of the group served as a control and remained seated for half an hour.
They measured the effect using blood analyses, as well as by measuring synovial fluid (the fluid that lubricates joints). They then measured various substances in the blood and synovial fluid, focusing on molecules associated with inflammation. Mild inflammation contributes to the development of osteoarthritis [4]. They examined both the types of cells that increase the risk of inflammation and those that decrease it.
They also looked at a substance called cartilage oligomeric matrix protein (COMP) in the synovial fluid. This substance tends to accumulate in damaged knees. People with osteoarthritis have about much more of this substance in their synovial fluid [5].
They found that after running, the two cell types that contribute to osteoarthritis were reduced compared to the baseline (before running). They also observed that running resulted in lower COMP levels in the synovial fluid. COMP from synovial fluid was found to be partly transferred to the blood (where it is quickly broken down [6]).
“Sitting is Worse for the Knees than Running”
In the control group that remained seated, the opposite happened. Both COMP and the amount of harmful cells increased after sitting for half an hour. This was unexpected for the researchers. As a sedentary control group, they expected constant values to compare with the effects of running.
However, sitting itself turned out to be a harmful activity when it comes to the risk of future joint problems.
Conclusion
The most recent research had the limitation that synovial fluid could only be collected from 6 out of 30 participants. In addition, the researchers would like to investigate the effects of longer distances in future research.
However, the notion that running is bad for the knees seems to be largely debunked. Not only does research not indicate harmful effects, it actually shows protective effects.
References
- Williams PT. Effects of Running and Walking on Osteoarthritis and Hip Replacement Risk. Medicine and science in sports and exercise. 2013;45(7):1292-1297. doi:10.1249/MSS.0b013e3182885f26.
- Krampla WW, Newrkla SP, Kroener AH, Hruby WF. Changes on magnetic resonance tomography in the knee joints of marathon runners: a 10-year longitudinal study. Skeletal Radiol. 2008 Jul;37(7):619-26. doi: 10.1007/s00256-008-0485-9. PubMed PMID: 18483739.
- Hyldahl RD, Evans A, Kwon S, Ridge ST, Robinson E, Hopkins JT, Seeley MK.
Running decreases knee intra-articular cytokine and cartilage oligomeric matrix
concentrations: a pilot study. Eur J Appl Physiol. 2016 Dec;116(11-12):2305-2314.
PubMed PMID: 27699484. - Davis, J. M., & Matteson, E. L. (2012). My Treatment Approach to Rheumatoid Arthritis. Mayo Clinic Proceedings, 87(7), 659–673. http://doi.org/10.1016/j.mayocp.2012.03.011
- Tseng, Susan, A. Hari Reddi, and Paul E. Di Cesare. “Cartilage Oligomeric Matrix Protein (COMP): A Biomarker of Arthritis.” Biomarker Insights 4 (2009): 33–44. Print.
- Andersson ML, Petersson IF, Karlsson KE, Jonsson EN, Månsson B, Heinegård D, Saxne TDiurnal variation in serum levels of cartilage oligomeric matrix protein in patients with knee osteoarthritis or rheumatoid arthritis. Ann Rheum Dis. 2006 Nov; 65(11):1490-4.
