A few months ago I bought a pair of Powercranks in an attempt to improve my cycling and even out some annoying power differences between my right and left legs.
I have discovered some amazing results with these Powercranks, in that they have really awakened some new muscles for pedalling in that circular motion. These muscles are especially related to the up motion of the cycling stroke.
In the book, Triathlete’s Guide to Bike Training by Linda Wallenfels, she explains the importance of unloading the other leg while pedalling down with the opposite leg. She states that if both legs are pushing down, even though one leg is really concentrating on the down stroke, the other leg can cause unwanted energy wastage by actually resisting the downstroke of the downward pushing leg.
Thus, the upstroke of the leg gains importance in not only helping with the overall circular motion of the pedal stroke, but also in unloading that leg so that it does not tire the downstroking leg.
These muscles require training, as only a set of Powercranks can do. I am finding that I can generate more overall power now by adding the upstroke to help the downstroke of the leg. It seems that Powercranks are the only tool that can truly isolate the legs to exercise this motion and to activate those upstroke muscles. Single leg pedalling just doesn’t seem to cut it.