The body saw exercise builds core strength, protects the spine, targets the serratus anterior, and even hits the trapezius and latissimus dorsi muscles. It's normally performed on a slippery apparatus like Val Slides or a slide board. You just pull your body back and forward.
But not everyone has access to sliding gadgets. Luckily, you can find stability balls at most gyms. As a bonus, the ball also challenges stability and core control, and the anterior core musculature is hammered even more. The irregular oscillations of the ball make it very challenging.
Adding a resistance band increases the tension.
Lift one leg off the ground.
Use a foam roller. This actually rolls out the extensors on the backside of the forearm and surprisingly hits the core a little harder.
It can also be performed in a lateral position to target the obliques and activate the glutes.
Give the body saw a shot and drop those boring planks!