A new study suggests low bone density and osteoporosis begin in cyclists before age twenty and last long after our riding days are over.
Avid and passionate cyclists share a common trait. They love to ride their bikes, and most would spend every spare second in the saddle. It’s in their DNA. Why not? Cycling does wonders for the body and mind. Not to mention the feeling of freedom, the sense of accomplishment, and the social bond fellow cyclists experience after a good ride—indoors or out.
Unfortunately, as Longfellow professed, “Into every sunny life, a little rain must fall.” For cyclists, rain falls as one of riding’s few negative consequences—Low Bone Density and Osteoporosis.
A May 2023 study published in the Journal of the American College of Sports Medicine examines the short and long-term forecast. The projections are gloomy, but the future is bright if you heed the warnings.
Scientists examined 93 male and female elite cyclists at varied stages of their careers. The Early Career group consisted of cyclists under 20 years that raced in a professional or national talent program. Advanced Career racers were over 20 years and affiliated with a WorldTour or continental cycling team. Retired racers with a minimum of five years WorldTour experience and under 50 comprised the Postcareer group.
The Results Showed Low Bone Density in Cyclists
The cross-sectional study assessed Bone Mineral Density (BMD), body composition, training history, lifetime sports participation, and blood markers related to bone health and low energy availability. Scientists recorded a Dual-energy X-ray absorptiometry (DXA) assessment of BMD at the lumbar spine, hip, femur, and whole body. The researchers assessed the racer’s current and past bone-specific physical activity data through a questionnaire (BPAQ).
Twenty-seven percent (27%) of Early Career male racers exhibited low lumbar spine BMD but no osteoporosis incidence. Forty-five percent (45%) of the females in the group had low BMD of their lumbar spine, and 10 percent had osteoporosis.
In the Advanced Career group of male racers, 64 percent (64%) had low BMD of the spine and 73 percent (73%) of the total body, with a 46 percent (46%) incidence of osteoporosis. Of the females, 45 percent (45%) had low spine BMD, and 20 percent (20%) were osteoporotic.
Fifty percent (50%) of the retired racers showed low BMD of the spine, and 20 percent (20%) had osteoporosis. The females in the group displayed a 20 percent (20%) occurrence of low spinal BMD, but none had osteoporosis.
What does it all mean for low bone density in cyclists?
The most significant factor determining adult BMD is bone mass achieved during adolescence, and the cumulative amount of bone loading forces experienced over a lifetime. Decreases in BMD occur if those forces are removed despite previous gains, as is the case with cyclists, who tend to spend long periods in the saddle and off their feet.
In the study, lifetime bone-specific physical activity, as assessed by the BPAQ, strongly correlated with current BMD values across all groups. Despite this, it’s staggering that low BMD develops rapidly in early-stage cyclists regardless of prior athletic activity.
Equally as alarming, bone is less responsive to growth with increasing age. The study indicates that low BMD, the negative consequence of a long career, is not fully reversible and somewhat limited. A high percentage of the retired racers exhibited persistently low BMD values.
The researchers found that low energy availability plays a vital role in cyclists with low BMD. Susceptibility to fracture was higher, emphasizing the importance of healthy bones for cyclists.
Factors That Cause Low Bone Density in Cyclists
- Cycling is a low-impact, non-weight-bearing activity performed in a relatively fixed body position, significantly reducing bone loading forces. Anderson (2018) and Omedillas (2012) noted that cycling stresses leg muscles, which pull on bones but does not substantially increase the physiological bone remodeling mechanism.
- Recovery time from racing and training frequently involves non-weight-bearing activities, such as sitting and lying, to reduce or eliminate muscular strain.
- Cyclists generally have low body weight, which is a risk factor for osteoporosis.
- Poor nutritional health practices to obtain and maintain low body weight may contribute to a lack of vitamins, minerals, and nutrients required for healthy bones.
- Endurance exercise leads to hormonally mediated suppression of bone turnover by directly decreasing bone-promoting hormone synthesis and secretion and indirectly through energy deficits created.
- Calcium loss through the skin while sweating is a risk factor, especially while training indoors, when the perspiration rate tends to be more significant.
- Virtual cyclists may be at increased risk because indoor cycling lacks a significant weight-bearing component, allows for excessive calcium loss through the skin, negatively affects hormone-mediated bone turnover, and is often associated with inadequate dietary intake of certain nutrients.
How to Improve Low Bone Density in Cyclists
- Incorporate impact or resistance activities, called osteogenic (bone growing), into your training regimen as a preventative measure or treatment plan.
- Encourage younger riders to participate in bone-specific physical activities like jumping and running sports.
- Consume a balanced diet or supplement (as per recommendation) to ensure adequate daily intake of calcium and vitamin D.
- Vary the types of cycling, including more dynamic activities like mountain biking, which include larger ground-induced loading forces from terrain differences.
Dietary Suggestions For Low Bone Density in Cyclists
- Eating the recommended daily intake of vegetables provides a source of vitamin C, which stimulates the production of bone-forming cells and protects them through its antioxidant effects.
- Since 50% of bone is protein, an adequate intake is required to ensure proper calcium absorption to promote bone formation, decrease breakdown, and help preserve bone mass during weight loss.
- Ensure adequate intake of the vitamins D and K, either through a balanced diet, healthy exposure to sunlight (in the case of D), or supplementation (as per recommendations).
- Collagen is the main protein found in bones, and supplementation (as per recommendations) may be beneficial in promoting bone health.
- Include foods high in magnesium and zinc in your balanced diet to provide necessary precursors to other bone density-promoting nutrients.
- Consuming foods high in omega-3 fats may have anti-inflammatory effects and help protect against bone loss during aging.
Strength Training Tips to Counteract Low Bone Density in Cyclists
- Apply multiple varied bone loading forces to stimulate growth. The goal is to provide unique weight-bearing forces by changing movements, amount of resistance, and intensity.
- Choose exercises involving larger muscle groups. Since larger muscles accommodate the stress of higher resistance, there is more significant potential to generate total force.
- Allow sufficient rest between sets. Higher resistance levels needed to stimulate bone growth require adequate recovery to generate strength and power.
- Be sure to focus on the primary areas. Bone density is site-specific. Therefore to promote growth in the most often affected hips, pelvis, and spine, target exercises that apply bone-loading forces to those regions.
- Include plyometrics in your training. Impact and jumping exercises stimulate bone growth through the high forces of their rapid muscle contractions and the variable, uneven, and fast rate of load application.
Conclusion—Low Bone Density in Cyclists Can Be Prevented and Treated
As the study and others like it overwhelmingly suggest, low bone density in cyclists is a clear and present danger. It’s essential to address the potential for declining bone health early on when our skeletal system is in its formative years.
I should be clear from the get-go that any form of exercise and physical activity will offset the risk of developing most musculoskeletal-related disorders. Unfortunately, it is not a simple cause-and-effect equation for cycling and skeletal health. Riding more doesn’t mean that our bones will be stronger. It is quite the contrary!
However, there is always time. By adding a few focused and specific bone load-producing exercises that stress your spine and lower extremities in a random and impactful manner, the risk of adverse consequences can be reduced or avoided and slow the decline in bone density.
Semi-retired as owner and director of his private Orthopedic Physical Therapy practice after over 20 years, Chris is blessed with the freedom to pursue his passion for virtual cycling and writing. On a continual quest to give back to his bike for all the rewarding experiences and relationships it has provided him, he created a non-profit. Chris is committed to helping others with his bike through its work and the pages of his site.
In the summer of 2022, he rode 3,900 miles from San Francisco to New York to support the charity he founded, TheDIRTDadFund. His “Gain Cave” resides on the North Fork of Long Island, where he lives with his beautiful wife and is proud of his two independent children.
You will read him promoting his passion on the pages of Cycling Weekly, Cycling News, road.cc, Zwift Insider, Endurance.biz, and Bicycling. Chris is co-host of The Virtual Velo Podcast, too!