Position
Sit in a ready position with your legs bent at an approximate 90-degree angle. Point your feet straight ahead with your ankles directly below your knees. Place the balls of your feet onto an elevated platform. Begin with your heels just below your toes, tension on your calves, and the weight just off of the rack.

Technique
Contract your calves. Begin pulling your heels up, keeping your ankles stable and your feet pointed straight ahead. Continue to pull your heels up until your ankles are fully extended. Lean slightly forward while maintaining proper spinal positioning. Hold, continue to contract your calves while stabilizing with your ankles. Slowly bring your heels and legs back down to their original starting position. Repeat.