Jackknife

When it comes to getting rid of stomach fat and working the core, some trainers suggest that the Jackknife is one of the better tools for achieving not just a tighter stronger core, but a six pack too. It’s called a Jackknife because when you’re actively engaged in doing this exercise you look like a semi open pocket knife while doing it. There are a few variations of this exercise, both with and without weights.

While many people are familiar with regular sit ups and crunches, and perhaps many have mastered them, both alignment and proper execution are an integral parts of seeing results with a Jackknife and avoiding injury. This exercise works the rectus abdominis, which runs down both sides of the front of the abdomen, but it also engages a whole host of other muscle groups, including the oblique muscles.

To get ready to do this exercise, you will need to get your mat out and lie down with your hands placed along your sides. Then, at the same time, raise your body up, bringing your knees and torso into a “V” position so that the hips and knees are flexed. While raised up, your fingers should be reaching for your toes, whether they reach them or not. You then move back down into your starting position, lying flat with your waist, hips, and knees extended. You’re then free to repeat the exercise until you’ve done a set.

While doing this exercise, it’s optimal to start each rep with your upper back flush to the floor so that the core muscles work together synthetically bringing more energy to the workout. Also, you should keep in mind that the rectus abdominis and oblique muscles contract when the waist muscles flex, if this does not occur, then these muscles don’t get the full benefit of this workout. So, rather than being fully engaged in this exercise, they just act as stabilizers.

The Jackknife sit up can be used by individuals of all fitness levels, from beginner to advanced, but some individuals may want to add some resistance to their workout as they get better at doing it. Some trainers and experts suggest that by using a medicine ball you can make doing the exercise more challenging. Lastly, while this particular exercise can be an effective tool in a stomach fat workout, other exercises are typically used too, including a variety of crunches, standing exercises, and moves involving the use of gym grade machines, like the Seated Ab Machine and the Captain’s Chair.