This works your upper arms and shoulders. Get into plank position with your arms slightly wider than shoulder width. Clench your bottom, brace your abs and, keeping your neck in line with your spine, slowly lower your body to the floor as far as you can go without collapsing.
Keep your elbows as close to your body as possible. Pause briefly then push back up into the starting position. If that’s too hard, you can do this exercise on your knees with your feet in the air rather than in full plank. 6 REPS