Since I was fat, had a bad back and was a jogger with sore knees, I cycled for a long time using downward pointing toes, as far forward as possible, sort of like I was running on my bike, using one foot after the other. Having my heels up and toes down meant that I could push the pedals back a little at the end of the down stroke, or at least avoid hurting my knees by attempting to extend the crank. Downward pointing toes helps with spinning the pedals behind you as it were. I describe it as cycling like Road Runner (cartoon).Pedaling toe down works, and it is similar to running, so I think that most of us can do it quite easily. I think it is fast too.

But my butt muscles got weak (which made my knees and hips sore till I found this exercise) so I moved to a old-school rearward offset position, and attempted to use my glutes by pulling backwards, in the immortal words of Greg LeMond "scraping the mud off my feet." But I could not make a downward push, followed by a backward scrape work.

Then I started pushing with my heels down and pedalling technique fell into place. There was something counter-intuitive to pedalling heel down, because pushing forwards with heels down, made me feel like I was pushing my body backwards. But if you lower your heels you can start pushing earlier, and it is no more "counter-intuitive" than using a pedal powered go-kart. Once I realized that pushing forwards drives my bike forwards (dur) "scraping the mud off the bottom of my feet" took on a different meaning.

I had always thought that I would be scraping the mud off my feet on the level ground beneath me, as one does if one steps in some mud, or something. But now I find it easier to visualise it as (wattle and) daubing a wall in front of me. I push forwards heel down and then scrape the mud on the sole of my feet into the wall in front of me, pulling back with my glutes. And this is how I have finally understood glute intensive, LeMond style (?) pedalling technique.

It has two or three advantages (other than providing exercise for weak old glutes)

1) Just as you are running out of forward/down stroke you pull back to leave that mud on the wall, and this acts as a sort of whipping motion that serializes the use of your 1 quads in your thigh and 2 glutes in your butt. This means that instead of muscles taking it in turns, their power is additive. Whipping motions achieve speed.

2) Since I am pedalling by pushing heel down earlier starting at the top of the cycle and scraping the mud from about 5pm to just past 6pm, each leg is just about active for more than 180 degrees (even if ever so slightly, even if there is only that perception) such that instead of taking it in turns, my legs feel like they are cooperating, and the push of one leg overlaps slightly with the pull of the other. It is a great feeling.

3) You can use your calf muscles, at the scrape point too. I don't, yet.

I cycled for about 20 years without understanding the "scraping the mud off the soles of your feet." Now I understand it as (wattle and) daub whipping.