Punch or Pull?
Use Higher Pivots for Longer Power
by Kent Ford

As a teaching trick, instructors often advocate punching out at eye level during a forward stroke. While this is useful for developing torso power and blade position, it isn't exactly correct for ultimate power. In each forward stroke you want to extend the tip of the blade forward, rather than reaching both arms forward for the plant. You'll pull yourself further if the tip of the blade enters the water farther forward.

Reach with your bottom hand and bend your top arm slightly. Then use your top arm to drive the blade into the water. This gets the blade fully submerged and ready for power. Once the blade is in the water, minimize how much you punch with the top hand. Instead, pull primarily with the lower arm and drive the top hand forward with your top shoulder.