Celebrity trainer Shannon Nadj is turning up the heat, both literally and figuratively.

For one, she sets the temperature of her LA-based studio, HotPilates, to 95°F. Breaking a sweat isn't an option, but a requirement for her clients, which includes Selena Gomez.

Then, she guides her class through a number of easy yet high-impact moves that promise to yield fast results.

In reference to the "Wolves" singer, the fitness pro told E! News, "The girl works out so hard...the booty is her favorite spot to emphasize."

Want to tighten up your glutes in time for swimsuit season? The trainer guided us through Selena's favorite moves, so you can get fit from the comfort of your home.