Recently an athlete asked me a question about power cranks:
How do you feel about powercranks? Are you familiar with them? They were mentioned in that article and I was curious. The idea is that each crank functions independently of the other. One leg cannot help the other. It is supposed to help pedal stroke.
Here is my response:
I think they are kind of gimmicky, and I have been debating the merits of not only them, but also of pedaling stroke drills in general. I have not read the original studies that power cranks has published on their site to see if I think they are valid or not, but the website does claim improved (efficiency? power output? speed? not sure which) on their site.
Cyclists who produce the most power do so by producing the power on the downstroke and minimizing interference of the upstroking leg. The upstroking leg does not need to generate any upward force, it just needs to get out of the way of the downstroking leg. This is s what they’ve seen when looking at the actual pedal mechanics of cyclists across all levels.
Using power cranks forces muscle groups like the hip flexors and anterior tibialis to do more work than they normally should, which on the surface seems OK, but the reality is that the leg extensors (knee extension/quads and hip extension/hams&gluts) do the bulk of the power production. So you are using a tool that forces a small muscle to do way more work than it is designed for. The hip flexors and ant. tib muscles are only designed ot clear the swinging leg from the ground in order to take another step forward. The gluts and hams and calves, however are designed for propulsive forward force.
Much of the current work in running is directed towards minimizing the involvment of the hip flexors and ant. tib muscles, where as power cranks do just the opposite. So how is it possible that two disciplines with similar muscle recruitment patterns can both be heading the right direction when the current “trends” or fads are going in opposite directions?
I personally have had an injured hip flexor and it sucks in a big way and takes a long time to recover from. In my case it was from hiking longs peak in winter boots that I was unprepared for. I did the climb fine, but my hip flexors weren’t prepared to lift my feet however many tens of thousands of steps it took to get to the summit with an extra 3 pounds on each foot.
My concern with thngs like power cranks is 1) Their benefit is questionable or small or possibly applies to a limited population 2) The risk if injury & overuse is real 3) You can get similar benefits by simply doing various pedaling mechanics drills…which are of questionable value in the first place.
Bottom line? Just ride!
I have a chapter written by one of the olympic training center coaches that discussions “pedal stroke” and how it differs among various disciplines (track sprinters, roadies, mountain bikers). What they found was that track sprinters have the most assymetric stroke with the majority of the force being produced on the downstroke, and mountain bikers have the “roundest” stroke…the majority of the force is still on the downstroke, but the overall shape of the power output around the pedal stroke is smoother.
The logic is that mountain bikers need to maintain traction on loose slilppery surfaces, so mashing on the pedals is counterproductive. But track sprinters who need to produce a ton of power are not worried about losing traction and mashign away gets them the best results, with roadies inbetween.
So then to take that study result and say that roadies should be practicing a smoother pedal stroke just doesn’t make any logical sense.
Even in that paper, the author admits that the “real” benefit of practicing a round stroke, if measurable would likely be in the single digit or less percentage points improvement which would only benefit pro and elite racers.
In my opinion, the vast majority of cyclists can spend their time much more wisely, less expensively and with less chance of injury than by simply concentrating on power output in a structured approach to training.
Things like pedaling drills just take away some of the boredom from winter training and are detrimental if it takes time away from more beneficial training methods. Professional cyclists who are training 30+ hours a week, however, can afford to spend time doing detailed work like that because it’s not possibly to put in 30 hours of intense riding…so their time is filled with a lot of “base” (ouch, there’s that word) and technique training.
That’s my current opinion, and I reserve the right to change my mind at any time.