Hitting some core stabilization work on the stability ball, in between sets.
Simple plank on the ball right? No big deal- except that it is hard as f**k. If you haven't tried this lately, give it a shot.
If you laugh at stability balls, you never used one correctly.
There are 1001 ways to kick your ass with this silly ball. Used correctly, it is a great asset in any gym.
And you can get them pretty cheap these days now that nobody likes them anymore.
Give your old stability ball some attention- your core will appreciate it.
MS, ISSA Master Trainer