Cycling and bone health

The role of exercise in regulating bone health is still not well understood. However healthy bone is typically related to increased mechanical loading. The magnitude of the strain could prevent and treat low bone mineral density  or increase the acquisition of bone mass during growth. Cycling can be considered a healthy sport because it improves physical fitness, cardiovascular function and prevents fat accumulation.

Adolescence is a sensitive phase for the acquisition of bone mass. Around 90% of bone mass is present at the end of the skeletal maturation phase. Many professional and master cyclists can be classified as osteopenic. Professional road cyclists have significantly lower bone mineral density  than the non-active population.  It is assumed that this non weight-bearing activity an insufficient stimulus to generate osteogenesis in clinically relevant bone sites. Rico et al, (1993) did not find differences in the bone mineral content  in total or any regional site between adolescent cyclists and age-matched sedentary controls. Similarly, Duncan et al. (2002) observed that female adolescent cyclists had similar bone mass density  values for the whole body, lumbar, femoral neck, legs and arms than non-athlete controls. However, when these adolescent cyclists were compared with a group of runners, female cyclists showed significant lower values for BMD for the whole body, femoral neck and legs, and lower bone strength.

   Up to 60% of peak bone mass is acquired during the peripubertal years, and peak bone mass is a significant predictor of postmenopausal osteoporosis for women.

The systematic review of the literature that has been done from Nagle and Brooks in 2011 showed that, there is concerning but inconsistent, limited-quality disease-oriented evidence, indicating that cyclists may be at risk for low bone mass, particularly at the lumbar spine. Additional longitudinal controlled intervention trials are needed to verify this data.

   The systematic review of the available literature that has been done from Olmedillas et al in 2012 showed that  it can be concluded that road cycling does not appear to confer any significant osteogenic benefit. The cause of this may be related to spending long hours in a weight-supported position on the bike in combination with the necessary enforced recovery time that involves a large amount of time sitting or lying supine, especially at the competitive level.

   The conclusion of these is that cycling when performed as only sports throughout adolescence can negatively affect bone health, as it is compromised acquisition of peak bone mass.

On the other hand, numerous studies in children and adolescents have been shown that simple and short jumping activities positively affect bone growth, and gravitational loading of the soil reaction encourages osteogenesis.

    In general, and in every age, is recommended that  if cycling is for the athlete, the only way to exercise his body, it could be better to accompanied by some form of exercise against gravity (jumping rope, jogging, basketball, volleyball, weight training) in order  to receive the body sufficient stimuli to mobilize the mechanism of osteogenesis. This, would be much better for his bone and body health.


                                                                          Haralambos Haralambakis
                                                                                  Physiotherapist

Sources:

Duncan CS, Blimkie CJ, Cowell CT, Burke ST, Briody JN, et al. (2002) Bone

mineral density in adolescent female athletes: relationship to exercise type and

muscle strength. Med Sci Sports Exerc 34: 286–294.

Kyle B. Nagle and M. Alison Brooks (2011) A Systematic Review of Bone

Health in Cyclists, Sports Health, vol 3, no 3, 235-243

Khan K, McKay HA, Haapasalo H, et al. Does childhood and adolescence

provide a unique opportunity for exercise to strengthen the skeleton? J Sci

Med Sport. 2000;3:150-164

Loud KJ, Gordon CM. Adolescent bone health. Arch Pediatr Adolesc Med.

2006;160:1026-1032

MacKelvie KJ, Khan KM, McKay HA. Is there a critical period for bone

response to weight-bearing exercise in children and adolescents? A

systematic review. Br J Sports Med. 2002;36:250-257.

Olmedillas H, Gonzalez-Aguero A, Moreno LA, Casaju´ s JA, Vicente-Rodrıguez G., (2011) Bone Related Health Status in Adolescent Cyclists. PLoS ONE 6(9):e24841. doi:10.1371/journal.pone.0024841

Olmedillas H, Gonzalez-Aguero A, Moreno LA, Casaju´ s J.A, Vicente-Rodrıguez G., (2012) Cycling and bone health: a systematic review, BMC Medicine, 10:168

Rico H, Revilla M, Hernandez ER, Gomez-Castresana F, Villa LF (1993) Bone

mineral content and body composition in postpubertal cyclist boys. Bone 14:

93–95.