Cycling is Good For Your Knees

A recently published study looked at the effects on the knees from bicycling, specifically at the symptoms and outcomes of knee osteoarthritis, and discovered that cycling can have significant benefits. (1)

Osteoarthritis is the most common form of arthritis and affects millions of people worldwide.  It occurs when the cartilage cushioning the ends of bones wears down over time.  Osteoarthritis commonly affects joints in the hands, knees, hips and spine, manifesting in morning stiffness, pain, deformity of the joint and joint activity limitations.  Severe cases can seriously impact quality of life.  (2,3)

This study from September 2024 was part of a long-term, retrospective, cross-sectional investigation from the Osteoarthritis Initiative (OAI), a multicenter, longitudinal, prospective observational study of knee osteoarthritis, which is in its 14^th year of follow-up.  The OAI has almost 5000 participants.  The OAI is partially supported by the National Institutes of Health/ National Institute of Arthritis and Musculoskeletal and Skin Diseases in the US. (1)

Subjects for this investigation were gathered from the OAI and included a total of 2607people, 44.2% male and 55.8% female.  Average age was 64.3 years (ranging from 40 to 80 years) and average BMI (Body Mass Index) was 28.5.  All of these participants had elevated risks of developing knee osteoarthritis due to excess weight, family history or previous injuries.  These individuals were not athletes but just regular people, some of whom enjoyed riding their bicycle.  The study compared those who reported any history of bicycling with those who were non-cyclists. (1)

As a part of the study the researchers took X-ray images to evaluate indicators of osteoarthritis in each participant.  In addition, a self-administered questionnaire was employed at the 8-year study visit of each participant to quantify their involvement in bicycling during four time periods throughout their lifetime – ages 12 to 18; 19 to 34; 35 to 49; and over 50 years of age.  Outcomes measured were frequent knee pain, osteoarthritis illustrated through X-rays, and osteoarthritis diagnosed through symptoms.  (1)

Results showed that, compared to non-bicyclists, those reporting any history of bicycling had a 21% lower risk of displaying symptoms of osteoarthritis or having X-ray evidence of osteoarthritis.

In addition, observations showed that higher participation in bicycling during one age period and participation during more age periods resulted in lower indicators of osteoporosis.  (1)

Another investigation, also published in 2024, examined the preventive effects of physical activity on osteoarthritis as well. Data was obtained from the National Health and Nutrition Examination Survey (NHANES), a nationally representative cross-sectional survey conducted by the Centers for Disease Control and Prevention in the US which ran from 2007 to 2020.  Results showed that all types of physical activity considered in this study were associated with osteoarthritis in some way. (4)

Study participants were assessed for the physical activities they were involved in as follows (4);

• Vigorous work activity – activity that induces significant increases in breathing or heart rate for at least 10 minutes continually (Examples: hauling or lifting heavy weights, climbing stairs, excavating or building work)
• Vigorous recreational activity – high-intensity sports, fitness or leisure activities that generate significant increases in breathing or heart rate (Examples: jogging, fast or uphill cycling or basketball)
• Moderate work activity – activity that induces minor increases in breathing or heart rate for at least 10 minutes continually (Examples: brisk walking, or carrying light burdens)
• Moderate recreational activity – activity that generates a slight rise in breathing or heart rate for at least 10 minutes continuously (Examples: brisk walking, leisure biking, swimming or volleyball)
• Walking/ bicycling as transportation – getting to/from school/work/shopping through activity lasting at least 10 minutes continuously

Final results showed the following (4);

• Moderate work activity was a risk factor for osteoarthritis
• Osteoarthritis prevalence was lower in those engaging in vigorous recreational activity reducing the risk of osteoporosis by 39%
• Osteoarthritis prevalence was lower in those engaging in moderate recreational activity reducing the risk of osteoporosis by 21%.

Study authors point out that cycling is a very low impact exercise that helps to build strength in the muscles around the knee thereby protecting the joint.  The rhythmic motion of pedaling helps to distribute the synovial fluid within the knee, promoting lubrication of the joint and delivering nutrients to it. (4)

NOTE:  Synovial fluid is a thick liquid found inside our joints that slides between bones and cartilage to help them to move smoothly, keeping them from rubbing against each other and allowing ease of movement.  (5)

An unexpected bonus came from a study published in 2021 demonstrated that cycling for just one hour a week is linked to a 22% lower risk of dying prematurely. (6)

So, pick a nice fall day, put on your bicycle helmet and take your bicycle for a spin.  You’ll not only enjoy the outdoor exercise,  your knees will be the better for it.

 

SOURCES:

1  Lo, G.H., Richard, M.J., Kriska, A.M., McAlindon, T.E., Harkey, M., Rockette-Wagner, B, et al. Bicycling over a Lifetime Is Associated with Less Symptomatic Knee Osteoarthritis: Data from the Osteoarthritis Initiative. Med Sci Sports Exerc. 2024 Sep 1; 56(9):1678-1684. Doi: 10.1249/MSS.0000000000003449. Epub 2024 Apr 11. PMID: 38600648; PMCID: PMC11326993.

2  https://www.mayoclinic.org/diseases-conditions/osteoarthritis/symptoms-causes/syc-20351925

3  Glyn-Jones, S., Palmer, A.J., Agricola, R., Price, A.J., Vincent, T.L., Weinans, H., Carr, A.J. Osteoarthritis. Lancet. 2015 Jul 25;386(9991):376-87. Doi: 10.1016/S0140-6736(14)60802-3. Epub 2015 Mar 4. PMID: 25748615.

4  Huang, C., Guo, Z., Feng, Z. et al. Comparative study on the association between types of physical activity, physical activity levels, and the incidence of osteoarthritis in adults: the NHANES 2007–2020. Sci Rep 14, 20574 (2024). https://doi.org/10.1038/s41598-024-71766-9.

5  https://my.clevelandclinic.org/health/body/25002-synovial-membrane

6  Ried-Larsen, M., Rasmussen, M.G., Blond, K., Overvad, T.F., Overvad, K., Steindorf, K., Katzke, V., et al.  Association of Cycling With All-Cause and Cardiovascular Disease Mortality Among Persons With Diabetes: The European Prospective Investigation Into Cancer and Nutrition (EPIC) Study. JAMA Intern Med. 2021 Sep 1;181(9):1196-1205. Doi: 10.1001/jamainternmed.2021.3836. PMID: 34279548; PMCID: PMC8290339.