Lie face-up on a mat grasping something overhead or your arms flat at your sides. Pull your legs up so that they are at a right angle with your torso. (Theresa Hessler demonstrates at top of page.) This is your start position. Keep the position of your legs as consistent as possible. Now curl your hips up to the position shown in the second photo while exhaling. Your weight should be concentrated on your shoulders, not your neck. Slowly return to the start position while inhaling.
The Single Leg Bridge Exercise is a good way to wrap up your core workout in order to keep your core strong and balanced. The single leg bridge is a bit more challenging than the basic bridge exercise. It targets and strengthen the gluteus maximus and hamstrings, but done properly, it is also a terrific core strengthening exercise that targets the posterior chain and the back of the body.
First off, it's easy to sit back while doing this move, letting your hip flexors do much of the work. Second, if you keep a flat back, it limits the degree to which you can hit the upper abdominals—your back has to round! And finally, your hands should stay in the same relative position next to your head for the duration of the set. Letting them drift away on the eccentric and then pulling them back again beside your head brings a lot of shoulder and upper body into the move.
While legs should never be forgotten, this program is designed to concentrate on the abs and upper-body beach muscles. Hit legs on abs/cardio day by isolating each body part at the end of your routine. The idea of isolating muscle groups and upping the volume is predicted by research that backs applied solutions, which we have seen from those with rock-solid physiques. 
But instead of just trying to perform as many reps as possible, slow down and really focus on the quality of the movement—especially the eccentric, or downward motion, of the exercise, he says. “The eccentric contraction is the most important phase when sculpting any muscle.” Plus, focusing on quality over quantity will help protect your back (some experts say crunches can be potentially troublesome for guys with back issues.)
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