How can a human produce the greatest amount of physical power? One method of producing a great amount of power is a bicycle. The strongest humans can output several horsepower for a while using a bicycle. But this seems limited because it involves primarily the legs without involving other body parts. Another method is the sculling set-up. This seems fairly whole-body but is every limb working as hard as it can? And it seems power is wasted in bringing the oars back to the front. Similar to the sculling set-up is weightlifting. While the power here is only exerted over a small amount of time it must be considerable, and weightlifters tend to have great whole-body strength. Maybe the weightlifting motion could be adapted to produce power over a longer amount of time. Optimally a machine should engage every limb of the body simultaneously to the greatest extent possible, as well as the trunk strength, and it should not be burdened by inefficiency of motion. For example, a bicycle pedal can only move in a circle--is that the most efficient way for the leg to exert power or would it work better by moving up and down or in an oval? Whole-body motions like weightlifting are naturally limited by one or two groups of muscles. Weightlifters tend to have thin arms compared to the rest of their physique--the arms can only usefully be strong enough to keep up with the legs, which apparently do most of the real work. Can the human arms become as powerful as the human legs, or is there a fundamental biological difference? I know bodybuilders can have arms thicker than the average person's legs, but can they exert continuous power over long periods of time, like legs can?