Cycling is a great low-impact aerobic activity. Cyclists are usually more efficient on both hills and flat terrain when they pedal quickly (at about 80-85 rpm) rather than at slower cadences. Although cycling is considered a knee-sparing exercise because it does not require impact with the ground, the repetitive motion of pedalling can lead to a variety of overuse knee injuries. The majority of cycling injuries are indeed caused by overuse, which leads to cumulative tissue microtrauma and consequent symptoms. In overuse injuries the problem is often not acute tissue inflammation, but chronic degeneration.
Cycling is obviously very repetitive: during one hour of cycling a rider may average up to 5000 pedal revolutions. But which cyclists sustain overuse knee injuries? Basically, cyclists of every ability level are at risk: riding too hard, too soon and too far is the usual recipe for numerous knee problems. Touring cyclists often develop a knee overuse injury during or after one specific usually long ride. These sporadic high-mileage riders often do not train adequately. Patellar pain is the most frequent problem (for more information see our Patellofemoral problems page), followed by Iliotibial Band Syndrome. Bicycle maladjustments are also frequent in this group and amongst recreational cyclists.
Cyclists vs. Runners
Cycling and Running are two very popular sports, but compared to cycling, running seems to be a better way do build up leg bone density, while cycling regularly will improve on upper limb bone density. Runners have a bit less developed arm muscles. Apart from that, it seems that cycling and running have similar effects on body composition: participants in both have approximately 10% more leg muscle than the exercise abstainers.
The knee is the most common site of overuse injury in the cyclist, with an estimated 40% to 60% of riders experiencing knee pain. Like other cyclists, mountain bikers can suffer overuse injuries. Such injuries have been studied little in mountain bikers. In one study involving 265 off-road cyclists, 30% had recently experienced knee pain associated with mountain biking, and 37% reported low-back pain while riding; wrist pain and hand numbness were each reported by 19% (4).
Overuse injuries: in chronic cases, continued activity produces degenerative changes that lead to weakness, loss of flexibility, and chronic pain. Thus, in overuse injuries, the problem is often not acute tissue inflammation, but chronic degeneration (hence, for example, patella tendinosis instead of tendinitis). Pain in overuse injuries typically has insidious onset, but it may have an acute-on-chronic presentation. Overuse injuries most likely occur when an athlete changes the mode, intensity, or duration of training.
When evaluating knee pain it is very important to consider cyclists and bicycle anatomy, seasonal variations (early cycling season), training distance and intensity, and numerous human anatomical factors such as inflexibility, muscle imbalance, patellofemoral malalignment, leg-length discrepancy, etc. Do check the leg length: if the difference is up to 10 mm you can correct it by putting spacers under one cleat. If one leg is shorter by more than 10 mm you should try a shorter crank arm on the short leg side. Generally using shorter cranks keeps pedal speed up and knee stress down. Too long crank arms increase forces on the entire knee, but patellar and quadriceps tendons are most affected.