The movement is something of a cross between a Y raise (which, if youve tried before, is surprisingly challenging) and a lat pulldown, zeroing in on the rotator cuff muscles, rhomboids, lower traps, and lats.
"The goal is simple: keep the weights off the floor," Boyce writes in an Instagram post sharing the move. "You must keep your head in contact with the mat and the rest of your body down."
Grab a pair of super-light dumbbells. You might have to go as low as 2 pounds, or ditch the weights altogether, to keep proper form. That's okay. Even if you're Hercules, resist the urge to train this exercise heavy; at most, use 10-pound dumbbells.
Lay on your stomach, preferably on a mat, and keep your body in one straight line with your core braced and forehead flat on the floor. No matter what, lift your feet off the floor or let your ribs come off the floor. Tighten your abs to draw your ribcage in, and keep your chest on the ground. Keep your toes on the ground too.
Keeping a thumbs-up grip on the dumbbells, squeeze your shoulder blades to lift them off of the floor in a W position. All movement should come from your shoulder blades; dont arch your back or lift your forehead from the floor.
Extend your arms to a Y position, then pull your elbows back toward your sides, as if youre doing a lat pulldown.
During your workout warmup, perform 3 sets of 8 to 12 reps, resting 30 seconds between sets. Then go on and hit your upper body strength moves with better mobility.