This is currently one of my current favorite core exercises.  Here’s why I like it:

It’s a dynamic or movement-oriented challenge.

In this exercise, you’re asking your core to fully engage and hold steady while moving your leg out to the side.  If your hips are down, you’re focusing primarily on the abdominal muscles and hip adductors (inner thigh).  If you’re up in a bridge, your hamstrings, glutes, and back extensors are working as well.

It can be adapted depending on ability level.

Do this with or without the bridge.  Just do it well in the position you choose.  Whether your hips are on the floor or up in a bridge, focus on stabilizing the hips and every available muscle will work to hold them level.

I also like this exercise because I can do it.

I’m not kidding on this one.  I only like exercises that I can actually do. It’s good practice to choose exercises that are challenging but achievable with good form.