Triceps
Abdominals, Forearms, Shoulders
Start in forearm plank position, body straight, core engaged.
Place one hand (e.g., right) on floor where elbow was.
Push up with that hand while placing other hand (left) on floor.
Extend both arms into high plank (push-up) position.
Lower back down one forearm at a time (e.g., right then left) to return to forearm plank.
Repeat, leading with opposite arm on next rep.