Our lives require us to move in a variety of ways...usually at the same time! AND, life is not FIXED! We are asked to move in life while still maintaining balance. It makes sense to train this way for that very reason:
Grab your resistance band, stand on it with one foot and progress this exercise from Bicep Curls, to a Glute Squeeze/Hip Extension, to a Leg Press and then finish it off with a balance combination, challenging your core, as well!