I can relate to Ric's comments about MTB riders needing to pull up more to smooth out the stroke. Last weekend I rode a MTB up steep loose surfaced hills for the first time and traction was the limiting factor. Evening out the torque through the full pedaling cycle helped. On the road bike, I find pulling up while pedalling for a minute or two can provide some relief when my legs are fatigued by brining into play some different/extra muscles especially when climbing and I don't have any lower gears available to ease the pressure. I wouldn't ride like that all the time and on the flats I could achieve the same results by changing down and spinning faster.