This exercise targets your calves and shins, but your quads, hamstrings, and glutes are all engaged.
How to do it: Stand with your feet shoulder-width apart. Without pitching your upper body forward, bend your knees about 45-degrees. Maintain this position as you rise up onto the balls of your feet and lower back down, moving only your ankles. Continue this movement for 30 seconds.
Variations: Angle your knees in or out to really target your inner/outer calf muscles.