Lance Armstrong's miraculous comeback from cancer and his domination in both the time trials and the mountains of the Tour de France have inspired many cyclists to imitate his extreme high-cadence style. The world watched Jan Ulrich appear to struggle up the climbs at 80 rpm while Lance rode away from him at 110 rpm. Many people wondered, Why doesn't Ulrich just shift to a smaller gear and spin faster? Hasn't Lance proven to the world that very high cadences are better?The answer is no. Lance rode away from Ulrich because he produced more watts per pound of bodyweight because he is a stronger cyclist - not because he has discovered a secret that Ulrich doesn,t know. Should you mimic Lance's high cadence? Maybe I can't tell you that, but I will give you some information that will help you figure it out for yourself.
When you pedal a bicycle, your muscular system produces power to propel the bicycle and your cardiovascular system delivers oxygen, fuels the muscles, and removes waste products such as lactic acid. Selecting your optimal cadence is a matter of keeping these two systems in balance. The optimal balance is different for each person.
Spinning at higher cadences reduces the watts-per-pedal-stroke, a measure of the force required to produce a given wattage. This makes the workload more tolerable for the muscles. Most experts believe that this is because fewer fast-twitch muscle fibers must be recruited to create the high torque levels required at low cadence. Pedaling with a too-low cadence increases reliance on fast twitch fibers, causing premature lactic acid accumulation, which makes your legs burn.
Pedaling with high cadence, however, does waste some energy. Imagine setting your bike up on an indoor trainer and cutting off the chain. If you spun 100 rpm, the workload would be zero watts, yet your heart rate would elevate significantly above resting. Just moving your legs fast does use energy. Research has consistently demonstrated that cycling at 40 to 60 rpm generates the lowest oxygen consumption for a given wattage. Pedaling at too high a cadence overloads the cardiovascular system's ability to deliver oxygen to the muscles. The most obvious symptom of this is ventilatory distress.
High-cadence pedaling works your cardiovascular system more, but reduces the relative intensity of the leg muscles. The key, then, is pedaling with enough cadence to keep your watts-per-pedal-stroke at a level that your muscles can handle, but at a cadence that will not overload your cardiovascular system. The optimal balance is different for every rider.
Lance Armstrong has an extraordinary cardiovascular capacity. His heart and lungs can deliver enormous quantities of oxygen to his muscles. Yet Lance does not posses huge, muscular thighs. His muscles are much more likely to be overloaded by high watts-per-pedal-stroke than his cardiovascular system is to be overloaded by the oxygen demand of the workload. Therefore, high-cadence pedaling, even at a slightly higher energy cost, is most effective for him. Jan Ulrich, on the other hand, is not gifted with the cardiovascular capacity of Lance, but has much greater muscle mass in the hips and thighs. His legs are able to withstand high watts-per-pedal-stroke, so he correctly minimizes the wasted energy to prevent cardiovascular limitation. Both Lance and Jan pedal using the cadence that is most effective for their unique physiology.
Each cyclist brings a unique set of genetics and training to the sport. The basic rules are, if your legs hurt more than your lungs, increase cadence. If your lungs hurt more than your legs, use a lower cadence.
If you decide that higher cadence pedaling might be more effective for you, now is the time to accustom your body to the different demands. Until you have learned the skills to pedal at very high cadence for long periods of time, you will be less efficient. Begin to develop leg speed now and it will be smooth and natural by next year's race season.
Source: trifuel- by Ken Mierke/photo from bikeradar
