Lie on your back with one arm extended straight up toward the ceiling, fist closed, eyes on your fist. Drive up onto the opposite forearm, then push further up onto that hand, sitting tall with your chest up - the raised arm staying vertical the entire way, as though balancing something on your fist. Reverse the movement with the same control, lowering from hand to forearm to the floor, and switch arms after your set.

Works: shoulders, core, obliques, triceps

Breathing: Exhale as you drive up onto the forearm and hand, inhale as you lower back down in stages.

Common Mistakes: Letting the raised arm tilt and wander instead of staying vertical, collapsing straight back down rather than lowering through each stage, and shrugging the supporting shoulder up into the neck.

Make Easier: Come up only as far as the forearm and pause there, building the range one stage at a time.

Make Harder: Add a hip lift at the top so you're bridged on one hand and both feet, or move on to Side Bridges or Reverse Plank Kicks.