HOW: You are going to be moving in a straight line forward and backwards in this exercise. Step backwards into a lunge position while reaching your opposite arm to your front knee. Drive your front leg in the ground and push yourself back up. Immediately step forward into a forward lunge with the same leg you stepped back with previously and reach your opposite arm to your front knee. Push yourself back up to the starting position and repeat.
FEEL: You should feel all the muscles in your leg working.