The walking lunge works the large muscles of the lower body. This exercise also targets your core, abdominals and back, and is great for balance. Begin standing with both feet together. With hands on hips, take one giant step forward. Be sure to step far enough out so that your front knee is directly over your ankle and not over your toes. Bend the front knee to approximately 90 degrees and the back knee bends in unison. Bring the back foot in and return to a standing position. Pause for 2-3 seconds and alternate legs. Walking lunges can be modified by adding light hand weights.