>>1379221Okay, here's the thing about using your upper body to generate leg power: you're not supposed to do that, and it will eventually lead to repetitive motion injury.
You should be pedaling from the hip, with your hip itself as motionless as possible, and your upper body *holding*, not moving around a whole bunch. If you can't do that then you need to spend some time in the gym working on your core strength, and on the bike practicing proper pedaling technique (as mentioned above).
>Source: Every cycling coach I've ever talked to>Supplemental source: me dealing with injuries related to poor pedaling techniqueYou can believe me or not, no skin off my nose, and feel free to do your own research to verify.