i feel that so called "ankling" is more important when riding road (as the cranks have no momentum from the fixed gear to pull you through the back side of the rotation), but it's an effective pedaling technique, especially when you develop those thigh muscles. some people develop this technique and feel it's like an extra set of muscles they never knew they had.

i had a road coach once who would constantly yell "heels up!"

one of the drills we'd do was putting the bike in the highest gear, 53x11 or 12, and pedal only by pulling up. builds muscle fast (and wears you out fast).