There are plenty of variations you could incorporate into your fitness routine, listed below are just a few!
1. Ankle Taps
Performed correctly, Ankle Taps target the obliques. Be sure to contract the abdominal muscles, drawing the navel down to the spine.
Avoid curling your shoulders forward, using momentum and relying on your back and neck to perform the motion.
One of the most common, and basic, is supine abdominal exercises, Sit-Ups are often done wrong.
When positioning your hands behind your head, it is best to consider them your support, not the force pulling you up.
The point is to engage your abs to pull yourself up, not your arms and hands, so place your hands behind your ears instead, or when you begin to feel yourself losing form.
The version you see in the video is one that is often seen in CrossFit gyms.