Scissor Kicks are similar to Flutter Kicks, but are even more demanding. This intermediate exercise works your hip flexors and nearly every muscle in your abdomen for excellent core conditioning.
To begin, place a mat on a level area of ground. Lie with your back and your head resting firmly on the mat, with your legs extended straight out and heels touching the floor.
Take your hands and place them palms down under your glutes to raise your hips slightly off the floor. Your lower back should still be touching the mat.
Now raise both feet off the mat a few inches. Engage your core, and keeping your legs straight, lift your right leg up high until the flat of your foot is facing the ceiling and the split between your two legs creates a 90-degree angle. The left leg should remain extended out in front of you and just a few inches above the floor.
Quickly bring your right leg down to its original position, and then quickly lift your left leg up and down in the exact same movement. This counts as one Scissor Kick.
Do as many as you can until failure.
If you find Scissor Kicks still too challenging, you can just lift your legs up to a lesser height. To avoid straining your back, make sure your lower spine is pressed into the floor and not arching upwards.