You can find this exercise on page 184 of the book Synergistic Golf.
Exercise Type: STRENGTH
Exercise Category: LEGS - FEET, POWER PRODUCTION, RHYTHM - TIMING, STRENGTH
Stand tall with feet slightly wider than hips. Lower down to a squat with weight remaining mostly in heels. Spring upward as high as you can reaching arms to the sky. When returning to the ground, decelerate body and use joints as shock absorbers by landing first on toes, then balls of feet, then heels. Repeat 10x for 3 sets.