Originally Posted by
cooker
It may partly depend on how much O2 you need to generate those watts, as O2 delivery is the rate limiting step. If the 40 watt downstroke consumes 40 unlts of O2 and the 15 watt upstroke consumes 18 units of O2 (again using hypothetical numbers), then you'd be better off pushing down a little harder, and pulling up a little more weakly
Interesting idea.
In cellular respiration, there is a set joule per oxygen yield. That becomes a question of whether some muscles lose more energy to heat than others, which I don't THINK is the case, but I don't really know about that. I would have assumed they had the same efficiency - differing from one another mostly in max force - but I guess I'm not sure. Definitely worth looking into.
This doesn't account for uneven generation of lactic acid and sending one muscle set into anaerobic work without the other, but but's a whole new can.