Do Waist Trainers Actually Work?

Thanks to the Kardashian family, many are aware of waist trainers and the signature "snatched-waist" look they promise to deliver. In fact, Kim sells them as part of her super-popular Skims line — and says she gifts them to all of her friends who have recently given birth to help them recover their shape. But are waist trainers effective, and what are the risks of using one? Let's dive into everything you need to know.

What is a waist trainer, anyway?

"A waist trainer is a device similar to a corset, typically manufactured from an elastic material," explains Kelley Vargo, MS, MPH, CSCS, a certified strength, and conditioning coach. Often, waist trainers feature a velcro strap that can be cinched around the waist or a bra-style hook and eyes that can be progressively tightened. The intention behind wearing one? "To create a slimmer waist and an hourglass figure," Vargo says. If worn consistently over time, waist trainers can create a pretty extreme effect (think: Kim K at the Met Ball last year).

The idea of using a garment to shape the waist is nothing new. "There's a historical aspect to waist training that goes back to the 1500s," says Jaclyn Fulop, a board-licensed physical therapist and founder of Exchange Physical Therapy Group. "Women would tighten corsets over a period of time to achieve a smaller waist size."

Waist trainers these days are made of different materials and not usually worn as tightly, but they promise a similar effect. "They claim to tone, slim, and shape the waistline — taking inches off the belly," Fulop says.

How do waist trainers work?

Waist trainers may deliver on some of their promises. "There may be some water weight shed through sweating from wearing a waist trainer," Vargo says. But it's important to note that losing water weight doesn't mean you've lost fat.

Waist trainers do sort of help change the shape of your body. Tightly-cinched waist trainers make it hard to use your abdominal muscles, which can make them weaker. This could make your waist appear slimmer over time since the muscles become smaller. "If your waist appears to be smaller after a few weeks, it's likely due to water loss and muscle atrophy," Vargo says.

Your waist will appear smaller while wearing the waist trainer since it works similarly to shapewear. But once you take it off, you may notice less of a difference in your waistline.

There are also some indirect ways a waist trainer may make your waist appear smaller. "A waist trainer can have some short-term benefits, like improving posture, as it forces you to sit and stand up straight," Fulop points out. That might provide an overall "longer" appearance. "A waist trainer can also encourage proper lifting technique [with weights or heavy objects] due to its rigid nature," Fulop says. And better form could mean better fitness.

What are the downsides of using a waist trainer?

The thing about waist trainers is that while they may have a few short-term benefits, the cons definitely outweigh the pros.

They prevent you from strengthening your core.

First, as mentioned earlier, wearing a waist trainer during exercise or in everyday life can make your core muscles weaker. "If worn too much, the core muscles will start to depend on the stability and support of the waist trainer," Fulop says.

"Waist trainers can become a crutch due to over-wearing and not simultaneously training the core appropriately," adds Brooke Cates, a prenatal and postnatal exercise specialist and founder of The Bloom Method. "If a person isn't implementing proper core and pelvic floor training and just hoping that the waist trainer will magically slim their waist, they will be highly disappointed."

Waist trainers mess with your breathing.

They've been shown to inhibit your ability to breathe deeply, Vargo points out. So wearing one might help your weightlifting form a little bit, but it may also mess with your exercise performance. It should go without saying but, as a reminder, how hard you work out is directly tied to your ability to breathe. This is why weightlifters who use lifting belts — which act similarly to waist trainers in supporting core muscles — loosen them right after performing a lift. What's more, reduced lung capacity can lead to fatigue or even loss of consciousness (i.e. fainting), Fulop says.

They can shift your organs and cause long-term health issues.

If worn for a very long time, waist trainers can also have the same negative structural effects as corsets. Mainly, wearing a waist trainer can shift the floating ribs or the ribs that aren't attached to your sternum. This may move internal organs, causing the upper organs in the area to move further up and the lower organs to move further down, Fulop explains. As a result, long-term waist training can also cause digestive issues, a decrease in circulation, rib damage, and a condition called costochondritis, which is inflammation of the cartilage in between the ribs.

They can cause pelvic floor issues, especially in women who have recently given birth.

Brooke Cavalla, a certified personal trainer, never considered wearing a waist trainer until after the birth of her second baby. It was a rough delivery, and her core felt super weak afterward. She started wearing a waist trainer because she wanted extra support, and the idea of shrinking her stomach and uterus was appealing, she says.

"About three weeks after my second baby was born, I started feeling a very strange 'bulging' in my pelvic area," Cavalla remembers. "Because this was my second baby and I have a background as a prenatal/postnatal exercise specialist, I knew what I was feeling could not be normal." After consulting with her OB, she found out she had a slight bladder prolapse, which meant her bladder was pushing against the wall of her vagina.

"Because my pelvic floor was already weak from a large baby and an aggressive delivery, wearing a waist trainer had placed even more pressure on my pelvic floor and caused a grade 1 prolapse," Cavalla explains.

Unfortunately, Cavalla's experience isn't that rare among women who wear waist trainers after birth. "Waist trainers can often be quite aggressive for the postpartum core (or any core for that matter) and even the more gentle ones can cause issues if not used correctly," Cates says.

"In the early days postpartum, the internal organs, uterus, and pelvic floor musculature are moving through a massive healing state and require the ability to move back into their pre-pregnancy spaces," Cates explains. Some external support can help with this, but most of the time, something more gentle is appropriate, like high-waisted compression panties. "Strapping on a waistband, sucking in your belly, and tightening an external object around your torso can sometimes do more harm than good," Cates adds.

What can you do to shape your waist instead?

Experts agree: The best way to shape your waist is through diet and exercise. "Processed, sugar-laden foods, drinking your calories, and calorically-dense foods should be minimized," Vargo says. In terms of exercise, she recommends core strengthening exercises combined with metabolic conditioning (like HIIT workouts). Vargo also suggests keeping track of your waist measurement while you make these changes. "And remember: slow and steady progress is lasting progress," she notes.

"Last but not least, if something sounds too good to be true, it is," Vargo says. "Stay committed to the journey, and you will see results."