This article was first published on August 12, 2009 as part of my Examiner column.

Weight-bearing exercise is recommended because it promotes bone health and slows the development of osteoporosis, which is the decrease of bone density due to mineral loss. According to the article, “Exercising with osteoporosis: Stay active the safe way,” by the Mayo Clinic Staff, “Weight-bearing aerobic activities involve doing aerobic exercise on your feet, with your bones supporting your weight . . . These types of exercise work directly on the bones in your legs, hips and lower spine to slow mineral loss. They can also provide cardiovascular benefits, which boost heart and circulatory system health.”

It is likely that mountain biking promotes bone
growth while road cycling does not.

Cycling is known as a non-weight-bearing exercise. It is low-impact since the rider sits on the saddle and pedals. Most mountain bikers believe that they do not reap the benefits of weight-bearing activity since they ride a bike, but they may be wrong. This may be one case where ignorance is bliss, but then again, so is knowledge.

Many riders are recreational cyclists who sit on the bike and ride gentle terrain, whether it is relatively flat, smooth singletrack or unpaved rail-to-trails. Some riders take a much more aggressive approach, however. They ride rocky and rooty terrain with long descents and challenging, steep climbs. This style of riding requires the rider to get out of the saddle and stand for much of the ride. Rigid mountain bikes require the ankles, knees, and hips to serve as shock absorbers, as with any classic weight-bearing exercise, such as running. Even with full suspension bikes, the rider uses his or her legs as shock absorbers.

Anyone who has made a long descent down somewhat aggressive terrain knows that getting out of the saddle is necessary for a comfortable, safe ride. Standing also allows the rider to make subtle weight adjustments to keep the bike balanced over varying terrain. While going downhill is often seen as an opportunity for rest, many riders know otherwise. Standing for long periods of time while navigating down difficult descents can leave the calves burning and the heart and lungs working hard. Stiff shoes are necessary for comfort while the feet support the weight of the rider.

Some uphill climbs require the rider to get out of the saddle for a standing climb. The rider mashes down on the pedals and uses the arms and upper back to get leverage while pulling on the handlebar. The rider’s weight is fully supported by the feet on the pedals, not the seat.

Mountain biking often requires the rider to stand
and absorb impact from riding trail obstacles and
features.

S.E. Warner, J.M. Shaw, and G.P. Dalsky published their study, “Bone mineral density of competitive male mountain and road cyclists,” comparing the bone densities of road and mountain cyclists in the January 2002 issue of Bone, the Official Journal of the International Bone and Mineral Society. The study demonstrated a higher bone mineral density (BMD) in mountain cyclists. The authors of the study stated that, “Higher BMD in the mountain cyclists suggests that mountain cycling may provide an osteogenic stimulus that is not inherent to road cycling.” Osteogenesis is the development of new bone.

Mountain biking offers the best of both worlds. It is a low-impact exercise that is relatively safe for the joints. For more aggressive mountain bikers, it can also be a weight-bearing activity that may stimulate the development of new bone tissue. Barring any unforeseen, clavicle-busting accidents, mountain biking can be quite good for bone health.

Related Article to Mountain Biking as a Weight-Bearing Activity

Moronacity: Mountain Biking IS a Weight-Bearing Activity