Start in a standing position, feet and hips facing forward.
Place a power slider under the ball of your right foot (a towel works too, or if you're on carpet, use a paper plate).
Slowly reach/slide your right foot directly out to the side as you sink into your left, coming into a side lunge. Your left knee stays behind the toes, your left hamstring is parallel to the ground, and your chest leans forward while maintaining a flat back. Keep the abdominals engaged.
Drive up through the left heel to return to the starting position.
Instead of stopping here, continue to move into a curtsy lunge, sliding the ball of the right foot back and on an angle behind the left leg. The left knee bends allowing the hamstring to become parallel to the ground as the chest tilts forward.
Drive up through the left heel again, engaging your hamstrings and glutes to return to the starting position to complete the rep.
Perform two to three sets, 10 to 15 reps in each side.