This is the cousin to the front plank. The hollow hold is a great core stability exercise and it’s a great teacher of how to activate the trunk. It’s also an easy exercise to progress, similar to the front plank, in that all you have to do to make it more challenging is to extend the levers.
Basic physics really 😉
In other words, you can begin hollow holds in a fetal like position (only you’re on your back) and as your trunk strength/stability improves, you can “open up” into a longer position (like in the video).
Give it a shot.