Expand/Collapse Your Chest
A chest drill using different dynamics and textures. Four ways to use your chest: stop it, take it round, press it into a box, then circle it. Stand shoulder width apart, planted firmly, and keep the arms still so the chest does the work.
Start collapsed, then expand in three stops, then collapse in three. Stop each time. Don't pump it. Go as far out and as far in as you can, and bend your knees to help the collapse.
The box is front, side, back, side. Inflate and press rather than snapping.