Setup: Position your body in a standard plank. Place one forearm to the ground and grab your 5- to 10-pound FitFighter with the available hand.
Action: Reach through with the weight and then transition into a lateral plank. To do so, stretch your arm down sideways through the grounded forearm and rotate your body into a side plank by reaching upward. Remember to control your body. Repeat for 15 to 20 reps each side.