It should be a crime for a gym to have a seated twist machine. It's almost guaranteed to cause a spinal injury, and it's not even very effective at strengthening your core muscles.
Yet, many fitness facilities around the country have this old-school piece of equipment. At my local gym, I've personally seen a wide variety of people using the seated twist machine—there's a kneeling version that's just as bad—from teenagers to old-timers. And I cringe every single time.
So what's the issue with the machine that looks like a high-tech torture device? We spoke with world-renowned spinal biomechanist Dr. Stuart McGill to find out.
Problem 1: Twisting Damages Your Discs
The seated twist machine is based on the idea that to train the obliques and improve rotational power, you need to perform exercises that involve some sort of rotation or twisting through the core. When you use this machine, your upper body stays in a fixed position while your lower body rotates on a swivel, creating a twisting motion through your lower torso, which you can see here.
The lumbar spine (lower back) is not designed to handle this type of twisting movement. The thoracic spine is better suited for twisting movements. The lumbar vertebrae are large and thick, and they can handle a lot of vertical force, but they are not designed for a high degree of movement—especially twisting.
The outer ring of the discs, situated between the vertebrae, look almost like the layers of an onion, with collagen fibers stacked layer upon layer. When you twist and create power through your spine, as occurs with the seated twist machine, it damages those fibers.
"We've discovered that's one of the most potent ways to produce a disc tear," says McGill.
Some people are able to twist more than others, elite gymnasts more than powerlifters. Regardless, this type of exercise is never appropriate.
McGill recalls a basketball team whose players did slam ball rotations to build core rotational power. In this movement, a med ball is attached to a cord, and the athletes rotate through their core to powerfully slam the ball against a wall. The movement is similar to what happens in the seated twist machine. Sure enough, several of the athletes suffered disc tears.
"People seem to do really well with seated twists for a short period of time and think they're getting really strong and it's a great exercise," he says. "And then the discs in their spine abruptly become highly symptomatic."
Problem 2: It's Not Even Athletic
Almost all team sports require some type of rotational skill, such as throwing a ball, swinging a bat, racquet or club, or shooting a puck. If you look at a properly performed rotational skill, there is no rotation through the spine. Instead, the core actually prevents rotation in that area.
"People think they use this twisting motion in the field of play," explains McGill. "Great athletes develop most of their power from their hips and shoulders. Poor ones use their spines."
Most of the rotation and power in these skills occurs when you drive your hips toward your target (i.e., the person you're throwing a ball to or the direction you're hitting a ball). Your core then braces to prevent rotation in your lower back. To finish the movement, there is typically a rotation through the upper back, which is OK.
"It doesn't matter if I'm measuring really good MMA fighters of someone who can throw a football 70 to 80 yards; they all create most of their power from the hips and transfer it through the core," states McGill. "The core actually stops the motion generated by the hips so there are no energy leaks."
The same goes for common daily tasks, like carrying groceries or putting heavy pots on the top shelf in the kitchen. Less rotation here will create a more resilient spine later when training.
Besides the fact that the seated twist machine won't make you any better, it reinforces improper movement patterns. If you use it, you're likely to rotate through your spine when you perform one of these skills, which can cause an injury.
What To Do Instead
First order of business—never do Seated Twists in your workouts. It's simply not worth it.
The core muscles are designed to keep your spine in a neutral position. Instead of deliberately training the core to rotate, we want to teach your core muscles to brace and prevent your lumbar spine from twisting and moving.
The three exercises below will help you achieve this critical ability.
Anti-rotation exercises like the Pallof Press teach your core muscles to prevent rotation. In this type of exercise, you hold a position and brace against an external resistance trying to cause you to rotate. It's much harder than it looks.
- Stand with your feet shoulder-width apart and your body next to a cable machine.
- Grasp the cable handle with both hands directly in front of your chest.
- Keeping your core tight, extend your arms in front of your chest.
- Bring your arms back to your chest to return to the starting position with control.
Sets/Reps: 3x8 each side
Med Ball Rotational Throws
This and other med ball throwing exercises increase rotational power, but in the proper manner discussed above. Remember, the core is preventing rotation in this type of movement.
- Holding a med ball in front of your waist, stand with your left side facing a wall about 5 feet away.
- Keep your knees and hips bent.
- Shift your weight to your right foot and swing the med ball to your right hip.
- Drive through your hips, rotate through your core and throw the med ball against the wall with an underhand toss.
- Catch the ball off the wall and immediately repeat.
Sets/Reps: 2-3x10 each side
Single-Arm Dumbbell Carries
To train your obliques—the muscles people intend to train with the seated twist machine—simply hold a heavy dumbbell in one hand and walk. This is a great way to improve core stability and protect your spine.
- Stand with your feet hip-width apart and hold a dumbbell with one hand to your side.
- Keeping your core tight, walk for the specified distance.
Sets/Distance: 3x30-40 yards
For more information on back health from Dr. McGill, check out his books, Back Mechanic: The Step-by-Step McGill Method to Fix Back Pain and Ultimate Back Fitness and Performance. You can learn more at BackFitPro.com.
Photo Credit: Getty Images // Thinkstock