Tip 2: CONTRACT THE HAMSTRINGS WHEN POSSIBLE
AB TRAINING IS HARD WORK. Rewarding, but hard nonetheless.
Nowadays, it seems everyone’s trying to make it easier with all the new fangled doodads and gimmick devices but you know what’s begun to happen? Rather finding it’s not easier, most people are also finding it's not nearly as rewarding. Go figure.
Here is an example: Exercise “expert” Tony Little talks (and shouts and screams and jumps up and down...) about targeting the abs” by using a strap that keeps your knees bent during floor exercises. Tony believes that if you keep the knees bent then the abs are "locked on target” because the hip flexors can’t assist in the movement—and the result is an increase in the safety and intensity of your abdominal exercises. That’s not necessarily true.
Studies using electromyograms (EMG) have shown that for the first 80 reps of a movement there is absolutely no safety advantage between performing sit-ups with either straight or bent legs. Also, bent-leg exercises still work the hip tremors but only through a partial range of motion. Such training will chronically shorten the hip flexors and tilt the pelvis forward. In fact, aerobics instructors who often complain of having protruding bellies, regardless of how many sit-ups they do, are often suffering from shortened hip flexors rather than underdeveloped abs. This posture (technically referred to as hyper lordosis) affects the proper biomechanics of walking, running, and jumping and can make the back, hamstrings, and groin area more susceptible to injury.
There is a way to minimize the involvement of the hip flexors during ab work and thereby increase exercise intensity. It’s a technique introduced by Vladimir Janda. and it involves contracting the hamstrings as you perform abdominal exercises. The hamstrings are antagonists to the hip flexors. When the hamstrings contract. the hip flexors must relax making the abs work harder.
The correct way to contract the hamstrings as you do sit-ups is to keep your knees slightly bent and simply posh down with the balls of your feet as you exercise keeping your toes pointed. For maximum effectiveness during exercises that have you working face up. place your feet on a small platform such as an aerobic step. Also, to minimize the involvement of the calves. point your toes away from you. Try it—it works!