Hailey Bieber Shows Off Her Toned Glutes From New Workout Craze After Admitting Pilates Has Become 'Bit of a Fad': Photo

Hailey Bieber's new workout routine seems to be working!

Recently, Bieber took to her Instagram Story to post a photo wearing a weighted vest and something less familiar to her followers: Blood Flow Restriction (BFR) training bands.

She paired the workout equipment with light gray yoga pants and a matching gray tank, wearing her hair in a slick-back bun while posing for the mirror selfie. She also made sure to show off her signature Snap-On Lip Case and Peptide Lip Tint from her brand Rhode.

The post comes just a few months after she claimed Pilates is "a little over" in an interview with TIME back in April, where the model weighed in on top health trends.

"Is that crazy of me to say?" She continued before adding, “I love Pilates, I really do, but I think it’s become a little bit of a fad, and it’s really hard to find really good teachers that care about form.”

Experts are more enthusiastic about this new craze, saying these BFR bands can fool your muscles into working more and getting a better "pump."

Paul Comsulea, a personal trainer in Southport, Connecticut, at Equinox, told the New York Post that BFR bands "help isolate the glute muscles from the hamstrings, forcing the glutes to do more of the work."

Comsulea explained, "The restricted blood flow tricks your muscles into working way harder than they normally would at that load."

The bands work by partially cutting off blood flow to the muscle, which builds metabolic stress in the area. That buildup creates a chemically charged environment that promotes muscle growth, meaning users can get comparable results while using lighter weights.

Since the glutes are under greater strain, people can typically see results similar to what they would get when lifting weights that are 20 percent to 30 percent heavier.

Comsulea added that the bands deliver the best results when combined with glute-focused moves, for example, kickbacks, bridges and other banded exercises, rather than exercises like hip thrusts or deep squats.

It looks like the mother-of-one is onto something.

In other recent Instagram posts, Bieber's behind has been looking snatched, getting her routine from her celebrity trainer Kirsty Godso.

According to Godso’s Instagram, her workout regimen is "12 Band Glute Medius Hip Thrust on each leg,12 dual elevated hip thrusts with heavy dumbell and 12 single-leg dual elevated hip thrust on each leg, then rest for 90 seconds and repeat for 3 rounds."

Comsulea said that BFR bands are best used as one part of a well-rounded workout, not a replacement for one.

He went on to say, “I will never recommend them to somebody who just started working out. It’s more for advanced training.”