Originally Posted by tomato coupe

A statement was made that there is an additional penalty for heavier riders (as compared to lighter riders) if they climb while standing because "you spend too much energy keeping that body weight going up and down", and you have echoed that. That statement is either incorrect or misleading, depending on how you look at it, and that is what my comment addressed.

Heavier riders expend more energy climbing than lighter riders, and the difference scales (roughly) with the mass of the riders. But, there is no additional penalty on heavier riders when both riders are standing -- the difference still scales (roughly) with the mass of the riders. For example, if a heavier rider expends 10% more energy climbing than a lighter rider when both riders are sitting, he will also expend 10% more energy when both are standing.