When I first used clipless I tended to literally pull the back wheel up off the ground when standing to climb. Just poor technique. Took me awhile to get the hang of spinning while seated, and more efficient pedaling while standing.

Younger folks who are well conditioned may get away with pulling up on the pedals without injury, and maybe put out more power. But that ain't me. I'm more likely to end up with hamstring spasms and knee problems.