Alternate Name: Single-Leg Leg Lift, Bent-Knee Leg Lift
Lay down on the floor and bend your legs with your feet flat on the ground.
Raise one leg off the ground keeping it in a bent position. Raise it until your thighs are a little bit past a fully vertical (90 degree) position.
Lower leg all the way down as close as you can to the floor without actually touching it.
Repeat movement for the desired number of repetitions.
Rest a few seconds and perform same movement with the other leg.
This exercise is great for your lower abs. If you want to increase the level of diffuculty, simply straighten your leg more and this will add more resistance making the exercise more challenging to perform.