Originally Posted by
big john
I only read the thing, I don't know how they measured, I would assume power meter of some flavor. Those are the first two things that popped up when I searched. I cannot vouch for their validity. I just wanted to introduce the idea to challenge the dogma that it's impossible to pull up and we should all throw away our pedals.
The way I read it, they had the test subjects concentrate on pulling up with some sort of "feedback".
Just to be clear I'm an advocate of using clipless pedals and have been using them since the mid 80's when I had a pair of early Look pedals. But the idea that you can generate meaningful additional power from pulling on the upstroke has been repeatedly shown to be false. At least at any normal cadence and significant power. There are edge cases like standing start track sprints and maybe very low cadence climbing when gear limited. But the studies tend to focus more on normal cadence at high aerobic power.
The study you cited is literally the only one I've seen that hints at some potential advantage from pulling on the upstroke. But it's not obvious from the Abstract what they actually did. When they compared flats with clipless they appeared to find no difference until they specifically asked the riders to actively pull on their pedals with some "force feedback", whatever that means. There is also no definition of "pedal effectiveness". It says they rode at constant power and cadence, so are they talking about muscle usage or torque distribution?
The studies I've read focus on measuring power distribution throughout the stroke and they all look the same with positive torque on the downstroke and negative torque (from leg weight) on the upstroke. Again this is all at normal cadence and significant aerobic power. Pro and amateur riders all have the same torque distribution, but the pros do have less negative torque on the upstroke as they use their hip flexors more effectively.
I could cite these studies, but it would just be a repeat of the last dozen similar threads. Plus there will always be guys claiming that they produce extra power from pulling up. I don't really care, but it would be interesting to see some actual power distribution data to prove it can be done. That I have never seen yet.