Straight leg raises
While lying on the back, relax the back and head on the ground, and extend the legs, keeping them straight and close together. Then, slowly elevate your legs straight up towards the ceiling, and hold for a few seconds. Then, slowly return to the initial position.
Start in the same position, and extend the arms to the sides. Tighten the abs and hold the legs straight out and lifted about six inches above the ground. Then, raise the left leg higher than the right leg, then lower it as you raise the right leg higher, but quickly, in a scissor-like motion. To control the movements, you can tuck the hands underneath the glutes. You should make 5 sets of 15 repetitions.
Lie on the side with a straight body, with the body weight distributed on the forearm, and the feet on top of each other. Then, raise the hips up off of the ground, powering the movement with the forearm, and thus aligning the body from the head to the feet.
Hold for several seconds, and slowly lower the hips. Repeat in 5 sets of 15 repetitions.
Start in the same position, but with the knees bent, and the left hand behind the head. Then, move the left elbow up and crunch as high as you can. Hold for several seconds, and contract the obliques. Next, return to the initial position and make several repetitions before you switch sides. Perform 5 sets of 30 reps.
Reverse hip crunch thrusts
You should lie on the back, with the head and neck on the floor, the arms by the sides, bent knees and flat feet. Next, roll the legs up towards the ears, bringing the hips up towards you, and hold for several seconds. You should make 5 sets of 15 repetitions.