Originally Posted by
waterrockets
It's actually beneficial, speedwise, to give more for hills and headwinds, then recover on the descents. On a steep climb, 5% more power will yield very close to 5% more speed. On the flats, nowhere near a 5% speed bump because of the cubic relationship to power (double speed takes 8x power) in air. On the climb, the air is such a small portion of what you're fighting, that the speed increase doesn't amount to much in the way of wind resistance.
Same thing for a stiff headwind. If you're pushing at 7mph into a 25mph headwind, then your air speed is 32mph. More power to get another single mph will only result in 3% more wind speed, but 14% more land speed, and 14% less time on that part of the course. Tuck and hammer in the headwinds.
We are talking apples and oranges here. My point is that hills (even if total ascent equals total descent) hurt your average speed compared to flats, which was the question DayGloDago was asking. While you are talking about the best strategy to go as fast as possible when there are hills.