|One of the attractions of multisport training and racing is the challenge of competing in an event that requires more than one skill. The obvious drawback is that mastering the skills needed for two or more disciplines becomes a more complex task. Even though multisport athletes face variable challenges, the concept of efficiency remains constant. This article examines one way to improve efficiency on the bicycle.
Since a bicycle magnifies human power output (i.e., cyclists are faster than runners) it is clear that any sort of inefficient energy transfer is similarly magnified. Because there are added moving parts and other variables such as bike "fit" and aerodynamics, there are more ways to waste energy.
A common source of wasted energy is found in the biomechanics of pedaling. Since the pedals of the bike can only circumscribe a circle, the idea is to get your feet to do the same thing. You can try to get the pedals to follow a shape other than a circle (e.g., a square) but you wont be successful. Instead, the inappropriately applied force on the pedals will be redirected in a way that slows you down.
If you examine the full 360 degrees of rotation of the pedal cycle, you can see that one half is the power phase and the other half the recovery phase. If you then break down the power phase into 4 increments (i.e., 45 ° segments) and look at muscle recruitment during each increment, it has been shown that different muscles wax, peak, and wane at different stages. Inexperienced cyclists have poor coordination with their muscle groups and so there is a choppy transition and wasted energy. More experienced riders have learned the neuro-muscular coordination needed, and the transitions of muscle recruitment are very smooth. They have learned to use the muscles together instead of against one another.
Certainly there is variation in the magnitude of this problem, and subtle inefficiency is harder to spot than the gross variety, but the first step is to look for it. A good cycling coach is an invaluable resource, but if you dont have immediate access to one then have some friends ride with you or video tape you. The first thing to look for is upper body motion, which is best seen from the side. If it looks like you are bouncing or "humping", then you are incorrectly applying pedaling force. Another sign, seen from behind, is referred to as the "sine wave". If the bike oscillates from side to side, or the wheels follow a sine wave on the ground, then you can be certain that there is inefficiency present.
After identifying the problem, the next step is to try to fix it. Without question, the best method to smooth out inefficient, choppy rotation is to perform high RPM (revolutions per minute) drills. (As a side note: maximum pedaling efficiency is usually found at 90 110 RPM). The high RPM drills ccan be done in a variety of ways. One method is to do sets in which higher RPM (e.g., 120 140) for brief periods of time (e.g., one to ten minutes) is alternated with lower RPM (e.g., 90 100). The goal is to cause your neuromuscular system to dampen out choppy power transitions from one muscle group to the next. To do these sets you will need to use an easy gear ratio (e.g., small front chain ring). As you progress to higher RPMs you will notice a threshold at which you start to bounce. Over time, as you adapt, this threshold will occur at higher RPMs. This lets you know that your efficiency is increasing and previously observed signs of "choppy" cycling will begin to fade.
Another great tool to improve pedaling efficiency is the fixed-gear bike. This is the type of bike used in velodrome racing. Be very careful and make sure you get professional instruction prior to use, because, unlike a road bike, there is no free-wheel -- YOU CAN'T COAST. If you stop pedaling suddenly the bike will slam you into the ground. A less dangerous alternative is to attend "spin classes", which are coached drills on indoor trainers. These sessions can really be a lot of fun and will improve your cycling.
So spin and enjoy.