There is no doubt in my mind that if you’ve been around cycling for any length of time, you’ve certainly heard of the terms “pedaling circles” or “fluidity”, as it relates to pedaling mechanics and more to the point, the smoothness of ones’ pedal stroke.
ONE LEG PEDALING DRILL? NOT SO MUCH
Historically, the underlying action item for most people looking to smooth out their pedal stroke is to learn how to “pull up” on the pedals during the upstroke aspect of the pedal stroke. This is most typically learned through one-leg pedaling drills. People doing these drills are easy to identify as they are the ones swerving left to right up a hill with one leg flailing out to the side with other runners, cyclists, (insert any recreational athlete), cursing them. So is all this really necessary?
The resounding answer is no. Here’s why – aside from looking ridiculous pedaling with only one leg up a hill, the reality is that by pulling up on the pedals you are actually lowering your efficiency.
Without getting too deep into the physics of it all, let’s first appreciate our good friend, gravity. If you were to put one leg on a pedal at the top of the pedal stroke, you don’t even have to put pressure on the pedal to make the crank turn, as gravity does this for you – how nice! While I know that I said that one-leg pedaling drills are useless, you will notice that when doing this drill, the only way to get a “smooth” pedal stroke is to let gravity push the pedal down and pull-up on the upstroke. This means that the force to pull up the pedal is essentially equal to what gravity’s effect is on your leg during the down stroke.
This is of course the opposite of what you want to happen. When pushing down on on the pedals, you utilize the glutes which are a very powerful group of muscles whereas pulling up on the pedals focuses on the hamstrings and hip flexor muscles, which are much smaller and produce much less force than the glutes.
Research by Dr. Jeff Broker, a former biomechanist at USA Cycling found that professional cyclists (who have visually smooth pedaling strokes) have more uneven pedal strokes than amateurs. Meaning – pros put much more emphasis on the downstroke than the upstroke.
In summation, a “normal” and efficient pedal stroke consists of more force being applied on the down stroke than the upstroke and a pedal stroke that has equal force being applied throughout the entire stroke, which is near impossible, is inefficient.
Now, you can and should work on the “smoothness” of your pedal stroke to make sure it is not visually choppy and has minimal dead spots, however that is a whole other blog post (Teaser: A choppy pedal stroke is mostly due to issues with ankle flexion and extension).