10 Minute Ab Workout - At Home Abdominal and Oblique Exercises Without Equipment

#5 Jackknife Crunches - 2 Minutes

Like the bicycle crunch, the jackknife situp is an advanced variation of the crunch that focuses on explosive movement to build muscles in the abdomen region.

Instructions

Step 1: Lie flat on the floor with straight legs. Extend your arms behind the head such that they are parallel to the floor.

Step 2: Raise the legs and the torso towards the ceiling at the same time to form a jackknife position. The arms and legs should be fully extended while in this position.

Step 3: Pause for a moment and return to the starting position.

Perform as many repetitions as you can in two minutes to finish the 10-minute high-intensity ab workout program for a flat stomach.

Important tip: You could add the side jackknife to the program to build your obliques.