Stand with your feet shoulder width apart on top of a long resistance band with a flat back and your core braced. Grasp either handles at each end of the resistance band, or just the opposite end of a looped band firmly in both hands (keeping hands shoulder width apart). Bring your arms out to either side of you, with your elbows bent at 90 degrees and your palms facing forwards. Keeping your chest up, bend at the knees and drive your hips back and down like you're sitting on a chair. Lower slowly with control until your thighs are parallel to the floor, inhaling as you do so. Pause at the bottom, then extend your legs and drive your hips forward to return to standing. As you do so drive both arms up overhead until fully extended. All the while exhaling as you do so. Repeat.