Gym, upper body
Lower your chest to the floor with your body straight as a plank, then push back up.
Best on camera: a slow, steady move with your joints in clear view.
Phone at hip height, about 3 metres away, filming you from the side.
Your whole body, head to feet, needs to be in the picture. The coach will remind you if it can't see you.
Hips sagging
Squeeze your glutes and stomach to keep a straight line.
Hips too high
Lower your hips until your body is one straight line.
Half reps
Lower until your elbows bend to 90° or more.