Depends on what you're trying to do. Sprinting uphill, yes, like the very devil. Starting a sprint on the flat, depends on the speed of your leadout. IME it's not possible to pull up at a very high cadence. People do pull up when going very hard while seated. One will see it on occasion in TdF videos and the like. But in general, no. One pushes forward at the top, does not normally push down, pulls back at the bottom and then unweights the pedal on the way up. Going harder starts as more pushing down and gradually becomes more of everything and finally the pulling up starts, too.

You can do two things to figure it out. One, put the bike in a very low gear and pedal extremely fast on level ground for a while. When you figure out how to stop bouncing, no matter how fast you pedal, you will have a decent pedal stroke. The other thing is to put the bike in your biggest gear and pedal without moving your upper body. When you figure out how to do that, you will have a strong, decent pedal stroke.