Question: I’ve often heard that unstable surface training isn’t very useful outside rehab because the extra muscle activation doesn’t always transfer to other sports or lifts. I’m curious how Stir the Pot fits into this. I know it can recruit the anterior core, but will that carry over to athletics and other lifts? How is using a stability ball for Stir the Pot different from doing 100 squats on a BOSU ball?
Answer: That’s a great question, and it doesn’t require a lengthy answer. For anyone not in the loop, when people hear “unstable surface training,” they often think of the usual tools—stability balls, BOSU balls, wobble boards, and other gadgets sold as a cure-all. If you buy the hype, unstable surface training promises to improve balance, boost muscle activation (especially in the core), help you shed a few pounds, and more. It even comes with knee valgus risks.
My view is that unstable surface training isn’t something to dismiss entirely. It can be effective, especially in rehab when we’re trying to reestablish proper movement patterns, improve muscle activation, or safely reintroduce external loading after an injury.
Over the past decade, some trainers have taken data from physical therapy—particularly for injured patients—and applied it to healthy clients in hopes of being more functional. The result hasn’t always been helpful. Instead of focusing on essential lifts like push-ups, hip hinges, or lunges, some people end up doing things like one-legged curls on BOSU balls, which may look impressive but don’t translate into real athletic gains. For healthy individuals aiming to get bigger, faster, stronger, leaner, prevent injuries, improve movement, or perform at a high level, unstable surface training isn’t the answer.
My partner Eric Cressey wrote The Truth About Unstable Surface Training, which argues that the field has become saturated for the wrong reasons. If you’re chasing balance as the main benefit, you might also read John Kiefer’s article Unstable Surface for Stability Training (often labeled Clown School). The bottom line is that solid floors work fine, and unstable surfaces can actually reduce athleticism, strength, balance, and movement quality more than they help.
A point from Kiefer’s piece: when you step onto ice, you tense up and limit your ability to produce maximum force—your nervous system protects you, which can lower strength, power, and speed.
Stir-the-Pot is a form of unstable surface training, but we don’t dismiss it entirely. At Cressey Performance we include this kind of training with our athletes, especially baseball players, to boost rotator cuff activation with a bottoms-up one-arm kettlebell carry, and we use bottoms-up variations with dumbbell presses, single-leg Bulgarian split squats, and Turkish get-ups. These are used alongside stable-surface lifts like squats, deadlifts, rows, chin-ups, and hip thrusts to build overall strength.
Regarding Stir-the-Pot, I see it as:
1) a useful way to train the anterior core
2) a way to progress the plank
I’ve heard people brag about how long they can hold a plank, but real benefit comes from learning to engage the front of the core and resist extension. Planks and their variations can help someone with chronic low back issues by promoting spinal stability and neutral spine, but there are diminishing returns if it becomes a contest of endurance or is done at the expense of technique.
The goal isn’t to run planks into the ground; it’s to focus on movement quality rather than quantity. If anything, I’d rather make planks more challenging than longer.
In short, Stir-the-Pot isn’t a magic fix. It has a place in a program when used appropriately, but it’s often overrated and not the best use of time for most healthy people aiming to improve in the weight room.
Wrap-up: Unstable surface training has its place, but it should be used thoughtfully and in the right context, not as the default method for everyone.
