Could you make it through the hardest workout in America?

The verdict is in: the hardest workout studio in America is (drumroll, please…) New York City’s Tone House.

Earlier this week, Classpass released its list of “Hardest Classes in America,” and Tone House beat out 20,000 other studios across the country for the top spot. The self-described “extreme, athletic-based group fitness studio” has earned a reputation as being unbelievably challenging, and according to reviews on the Classpass website it definitely lives up to the hype: “Hardest workout of my life. If you think you’re fit…think again.” “Wow just wow. Brutal but good.” “This workout kicked my ass.”

So what is it about Tone House that makes it so dang hard? The workout is utilizes sports conditioning sequences made up of full-body moves—and interspersed with sprints—to get your muscles burning and your heart racing. These sequences change every day to keep your body guessing, but many of the toughest moves are around all the time. Below, Tone House head coach Yusuf Jeffers reveals what they are.

5 moves from the hardest workout in America

1. Gallops: We’ve called Tone House’s Gallops “the hardest workout move you’ve never tried before,” and it’s for good reason. The move is basically running on all fours—the way a cheetah would—and requires you to transfer your weight from your hands  to your feet and back again. “Moving on all fours quickly with a decent level of coordination and agility is an unusual challenge for the body that’s unaccustomed to those positions,” says Jeffers. To try the move for yourself, start with your feet slightly wider than your hips and your knees bent. Place your hands on the floor in front of you and transfer your weight into them, then immediately hop your feet forward to meet them. Keep going as quickly as possible.

2. Bear Crawls:Bear crawls are another animal-inspired move that will give you the benefits of being on all fours. It engages your core, quads, legs, chest and shoulders, and improves your stability, mobility, and endurance—while also making you stronger. Start with your hands under your shoulders and knees under your hips, and press into your hands to hover your knees off of the ground at a 90-degree angle. Engaging your core and keeping your back flat and arms straight, pick up your right hand and left foot at the same time and move them forward. Repeat on the other side so that you’re moving forward slightly with each step.

3. Sled push-pulls: Aside from making you feel like a pro-athlete, sled push-pulls are great functional movement exercises that help with strengthening, conditioning, and mobility. “There are no isolation strength moves here,” says Jeffers. “You’ve got to put your whole body to work.” There are a few different ways you can use the sled, but a few trainer-favorites include forward running while pushing the sled forward to engage your quads, hamstrings, calves and hips, and backwards walking, when you pull the sled as you walk backwards slowly to work your hamstrings and glutes.

4. Up-downs: “From the beginning of class we make you work on moving your body quickly by changing levels and changing directions, which is always a quick way to increase that heart rate,” says Jeffers. Think: burpees, but with an even more challenging Tone House twist. The hardest version we’ve seen is called a “Lateral Box Drop Down,” which is not for the faint of heart. Standing on one side of a box or step, over it laterally (with your feet together) to the other side. Drop down into a burpee, then jump back up and repeat.

5. Sliding discs exercises: Adding the instability of sliding discs is a surefire way to make any move more challenging, and that’s exactly the goal at Tone House. “Whether moving with them on your feet or on your hands, these exercises turn the turf into an unstable surface that require some serious core stabilization and endurance to move from one end of the room to the other,” says Jeffers.  To try a “sliding push-up,” start in push-up position with your hands directly underneath your shoulders (either on your feet or modified on your knees) and place a slider underneath each hand. Lower down into a pushup with one arm while simultaneously sliding the other other arm straight out in front of you across the floor. Return back to start, and repeat on the other side.

To challenge your body even more, this is “the hardest oblique exercise you’ll ever do,” according to a trainer. And these are the six lower ab moves that pros say actually work.