Can Biking Make Your Bones Brittle?

Biking is becoming increasingly popular, both as a mode of transportation and as a form of exercise and recreation. Many cities have added bike lanes and rent-a-bike stations, making it easier for people to cycle in town. Heading out of the city, many people take advantage of the numerous mountain biking trails in parks and outdoor recreation areas. Biking clubs and associations are being formed, creating communities for people to discuss cycling, the best places to go, and common problems encountered.

 

As more and more people take up biking, it often becomes their primary form of physical activity. And biking is a great way to get exercise! It’s easier on the joints, as it’s a non-weight bearing activity, and you can travel far and fast, which keeps people’s interest longer. What many people don’t know, however, is that exclusively biking for exercise is highly associated with a loss in bone mass. In fact, one study comparing cyclists to runners found that cyclists were 7 times more likely than runners to have osteopenia (low bone mass) in their spines despite matching the runners in age, weight, nutrient intake, and activity level (1)!

 

Exclusive cycling has both short-term and long-term effects on bone mass. Two studies looking at females and males separately showed significant decreases in bone density over the course of just one year with cycling as the primary sport (2,3). Long-term losses in bone density were seen when comparing young cyclists, older cyclists, and age-matched normally active controls. Cyclists experienced a dramatic decrease in bone density as they aged, while their age-matched controls maintained healthy bone density levels (4).

 

In view of the studies I’ve cited above, it might seem that if you choose to cycle you are choosing to have low bone mass. But another study showed that there is a way to reverse this negative effect. Like the other studies, master cyclists were shown to have consistently lower bone mass than healthy non-athletes. However, both groups showed smaller decreases in bone mass with participation in weight training or impact training (5).

 

Low bone mass does not happen because you cycle. Low bone mass develops when you neglect to load your muscles and bones using weight-bearing activities. This means that I’m not telling you to stop biking. I am telling you, however, to include weight-bearing activities during your weekly exercise routines. This can be done by lifting weights, performing plyometrics and calisthenics, running, jumping rope, playing tennis, dancing, etc. To be a weight-bearing exercise means that your weight or the weight of the equipment should be working against gravity and loading on your muscles. The more you load your muscles, the more they’ll pull on your bones, and the more your bones will grow and strengthen.

 

So keep biking! Ride all the time, every day, but don’t forget to load your muscles and bones with weekly weight-bearing activities.

 

Sources

1.     Rector, R. S., Rogers, R., Ruebel, M., & Hinton, P. S. (2008). Participation in road cycling vs running is associated with lower bone mineral density in men. Metabolism57(2), 226-232.

2.     Sherk, V. D., Barry, D. W., Villalon, K. L., Hansen, K. C., Wolfe, P., & Kohrt, W. M. (2014). Bone loss over one year of training and competition in female cyclists. Clinical journal of sport medicine: official journal of the Canadian Academy of Sport Medicine24(4), 331.

3.     Barry, D. W., & Kohrt, W. M. (2008). BMD decreases over the course of a year in competitive male cyclists. Journal of Bone and Mineral Research23(4), 484-491.

4.     Nichols, J. F., Palmer, J. E., & Levy, S. S. (2003). Low bone mineral density in highly trained male master cyclists. Osteoporosis International14(8), 644-649.

5.     Nichols, J. F., & Rauh, M. J. (2011). Longitudinal changes in bone mineral density in male master cyclists and nonathletes. The Journal of Strength & Conditioning Research25(3), 727-734.