Medicine ball side twists
They can also be known as medicine ball rotations. What you’re going to do is you’re going to start out, kind,of, in a boat pose. So, your sternum is up, your chest is up, your ball is going to be in the center. You’re going to be on your sacrum and your abs are engaged.
What you’re going to do is drop the ball to the side, tap. Drop it to the side and tap. You can either go this slow or you can pick it up and go faster. So, we’re working our internal and external obliques, our transverse abdominals. If you’re feeling that in the lower back for whatever reason, you can do the same exercise with your heels on the ground.