Originally Posted by Carbonfiberboy

My guess is that your saddle is too high, forcing you to pedal toes down. If you have a trainer, you could set up a mirror beside you or have someone video you as you pedal. The sole of your shoe should be level at the bottom of the pedal stroke.

It's also possible that you saddle is not too high, but rather that you pedal toes down by habit.

It's also possible that you are "ankling" during the pedal stroke. "Ankling" means flexing your ankle during the downstroke. Relax your ankle all the way around the pedal circle, except lift your toe just before your foot goes over the top.

The other cure is to leave your fit alone and simply do one-legged, full-range-of-motion calf raises on a stair step. Put the ball of your foot on the stair, a couple fingers on a wall, the other foot hooked behind the ankle of the active foot, and go at it. Bombproof is being able to do one set of 30 of those with each leg. Do it every other day until you can do 30. I'm 77, not skinny, and I can do 30. Haven't had a calf issue since I started doing that.