Originally Posted by
abdon
Heck, the reason people instinctively climb off the saddle to fight a hill is because of that; they are trying to engage their legs in the strongest position they can muster. You do that for a while, and you'll feel your quads burning from lactic acid build up, showing you which muscles are carrying the bulk of the effort.
One caveat here; some people may tend to get off the saddle more often because their cranks are longer than they should be. That is so because the longer crank length creates a geometry where leg engagement calls for the quads to muscle through the revolution. If your intent is for high cadence, then too long a crank would be counter-productive for that goal. So would be too far a saddle position.
Getting off the saddle to climb puts your center of gravity further forward to enable putting out increased power to accommodate the grade. Same thing for sprinting---out of the saddle and forward over the bars for increased power.
You're right, of course, that seated climbing with the correct saddle position and gear choice is usually more efficient, especially for long climbs.
That said, feather-weight riders like myself can stand and climb efficiently for 15 or 20 minutes with no burning of the quads.