Rob Pannell visited the Tone House fitness studio while working out with The Program, a fitness group in New York City, in late 2016. After one workout, which he described as one of the toughest he’d experienced, Pannell was hooked.

The Tone House, a studio that markets itself as “extreme,” has become Pannell’s go-to gym for the past year. Pannell, who will suit up for the U.S. national team for this weekend's Team USA Fall Classic, trains alongside a number of professional athletes, as well as others competing in events like the Ironman.

“It got me back to that college atmosphere of being back in the weight room with your teammates,” Pannell said. “That's part of what drew me back to it. … It’s the toughest workout in New York City by far. You can't replicate it on your own because you can’t push yourself that much.”

The studio, founded by former college football player Alonzo Wilson, doesn’t focus solely on weight lifting. Wilson wanted his gym to feature more dynamic workouts that didn’t involve standing or waiting for certain weights.

Pannell said he’s done a variety of workouts, but none with more than 50 pounds of weight attached — i.e. the 25-yard shuttle, bear crawls and crab movements. He frequents the 8:45 a.m. and 10 a.m. classes, along with 10-20 others. The group goes through a 10-minute warm-up, followed by the hour-long Tone House workout and an ice bath to top it off.

Perhaps what he likes the most about the Tone House workout is that no workout is the same. Pannell said he’s always working on different muscles — something that he admits has given his game a boost.

“I felt more explosive than I ever have,” Pannell said. “Faster and just more powerful. By at the same time, I didn’t have that much more muscle mass. I was leaner. I felt my best. I don’t think I was breaking down my body by lifting so much weight. I saw it and people commented on it as well.”

Pannell and U.S. women’s national team player Laura Zimmerman frequent the Tone House, while others have stopped by.

“He works out very hard,” Wilson said of Pannell. “He’s not messing around. At the same time, he’s nice to all the other people that are there. That’s one thing Tone House does. … It really brings you together.”

The Tone House has two locations in New York City — one of 31st St. and another on 71st St. — and Wilson is hoping for further expansion. Regardless, Pannell said he’ll continue using the Tone House as much as he can.