Leg HoldMain Muscle: Abdominals Mechanics Type: Isolation Lie on the floor and place your hands (palms down) under the lower part of your back. Raise your legs about 6-12 inches off the floor and hold for 30 seconds to a minute. Repeat the exercise several times. For the more advanced, hold your legs lower to the floor and keep the legs elevated for a longer period of time. Focus on proper breathing and do not hold your breath.