Plank with Arm Lift
Get into the plank position (toes and forearms on the floor, body lifted). Your body should form a straight line (A). Brace your abs and carefully shift your weight to your right forearm. Extend your left arm in front of you (B) and hold for 3 to 10 seconds. Slowly bring your arm back in. Repeat with the right arm. That’s 1 rep. Do 2 or 3 sets of 5 to 10 reps, resting for 1 minute between sets.