EAST VILLAGE — The lights were low and the music was pounding during a recent early-morning indoor cycling class at New York Health and Racquet Club's Astor Place branch.
"Remember, breathe! Breathe!" yelled Rosa Puerto, the class instructor.
The bikers wiped sweat from their brows in a brief rest between intervals, then continued cycling furiously in time to the club-music beats.
But the class wasn't full of the gym's adult members — it was a private class full of teenage students from the East Village's Grace Church School using the facilities at the HRC under a new partnership.
"The first time, my legs did feel like they were going to give way," said Colin Davy, 15, one of dozens of students from the school that take an indoor cycling class once a week at the gym.
But Davy said the intense workouts set to loud music with an equally loud instructor have a surprising benefit — more energy.
"I felt good instead of groggy and slow," he said.
The private school has been using the members-only gym location since opening its high school at a new location at 46 Cooper Square in the fall of 2012 — in the former Village Voice space. It currently uses the gym three mornings a week — hosting dozens of students at cycling classes in the first-floor studio and hip-hop, creative movement and boot camp classes in the basement studio space for 45-minute sessions starting at 8 a.m. on Mondays, Tuesdays and Fridays, organizers said.
The school pays to rent out the space and for instructors from the gym, where memberships cost upwards of $100 a month.
"You can work as hard as you want to. You can push yourself and challenge yourself," said Illi Armijos, athletic and physical education director at the school. "You are doing the same thing as the kid next to you and it's not a competition."
Armijos said the 14- to 16-year-old students in the 45-minute cycling classes occasionally shy away from the workout's intensity, including high-energy instructors who bark orders at participants to change levels of pedaling difficulty and speed.
"They [students] understand it is positive yelling, pushing them, not negative yelling," Armijos said.
And Puerto, the instructor, doesn't go too light on her younger class.
"Their bodies are just developing, so I have to take it a little easier, but not too easy," she said. "They do have the energy and they work hard and they can hold it with any adults."
Lucy Judge-Tyson, 15, felt ill after her first indoor cycling class last year, but she said she is now a convert.
"The first class was really hard, but after a while you get used to it," she said. "It is the amount of work you have to put into it."
"When she [the instructor] yells, I find I push harder," Judge-Tyson added.
Grace Church also offers on-site physical education classes in their school, plus Pilates classes at The Pilates Boutique at Fourth Avenue and East 12th Street, so that students can all find activities they enjoy, they said.
"Our goal is to introduce kids to the work of group fitness in a safe and healthy environment," said Maryann Donner, the director of group fitness New York Health and Racquet Club.
Each trimester, students can try new classes.
"It is to help them find a passion for movement — their passion for movement," Armijos said.