Recover the starting position and change sides dsn pre workout Keep your belly stiff , using your limbs to create multidirectional forces that make your abs work harder. If you feel any type of tension in the lower back, reduce the range of leg movements . Uncover Your Abs MOVEMENT 3 To increase the power, put in the position of the plank, side on an elbow or, if you can, on the hand. Extend the free arm under the support arm, using 15-20 seconds in the movement. Turn it over and extend it towards the ceiling . Do not be in a hurry: stability is key to working the belly muscles , something not easy. Change sides and repeat. Uncover Your Abs MOVEMENT.