This work tries to capture the unseen energy (UV) surrounding the action: the 'entry into' and the 'exit from' the action. An attempt to challenge and expand the concept of "action" in work. My preoccupation with energy-action-matter-product relationships and dealing with how the body's effort produces mass. And how the relaxation of the muscles - at rest - changes its volume. Give-and-take, the trade relations between two fundamental dimensions that made the presence of material possible. 2021