Running is hitting its stride in NYC.

Studios and gyms across the city are bringing the boutique experience to the sport, which at its most elemental level just requires a pair of running shoes and some pavement to get going.

"People are starting to go toward the boutique industry, that's where the quality workouts are," says John Henwood.

The professional runner and coach, who's worked with middle-distance phenom Mary Cain, opened the indoor running studio TheRUN in Flatiron last week, offering treadmill classes at $34 a pop. He's hoping to gain traction among the city's running community.

"Running is massive in New York -- there are 60,000 New York Road Runners members, a lot of the races are sold out," Henwood says. "People love to run in New York."

Debora Warner also saw an opportunity for a treadmill-only studio in the city. The running coach opened Mile High Run Club this past November in NoHo, and is looking to open a second location in Manhattan before the end of the year.

"I don't think indoor running is a trend -- people have been running on the treadmill since there were gyms -- but the fact that the boutique model exists made this possible," says Warner, whose studio has been selling out classes and attracting elite runners like John Trautmann since opening. "The spinning market was saturated, and this seemed like an opportunity."

Beyond dedicated running studios like TheRUN and Mile High Run Club, fitness centers such as Barry's Bootcamp, Crunch and Equinox also offer treadmill-based workouts.

The draws of an indoor running class include a controlled environment; a workout geared toward all levels, regardless of pace; and, of course, the workout itself.

"I've had runners attribute their personal records to their training here," Warner says. "It really does make runners stronger and faster."

At 45 to 60 minutes, the workouts are efficient, too.

"You can condense an intense workout into a short period time and also can do terrific interval training," says Dr. Jordan Metzl, a sports doctor, coach and runner who is speaking at the 92Y on April 23 as part of a panel on running.

"I like the group dynamic that you can also get inside," adds Metzl, who sometimes coaches at Mile High.

Want to get running indoors? Here's where to go:

 

Barry's Bootcamp

 

The focus changes each class, from arms and abs to butts and legs, but each hour long workout will have you running treadmill intervals between strength training floor exercises for a high-calorie burn. $34/class; multiple locations, barrysbootcamp.com

 

Clay Health Club + Spa

 

The hourlong TRED group class is the studio's signature interval treadmill workout, incorporating high-intensity bursts on the treadmill along with sculpting drills off. Membership required; 15 W. 14th St., 212-206-9200, insideclay.com

 

Crunch

 

The gym's "badass cardio class," Tread N' Shed, does sprints and walks at various speeds and gradients to get you sweating. It also offers Runway, a 30-minute high intensity treadmill training class. Membership required; multiple locations, crunch.com

 

Equinox

 

The luxury gym added Precision Running -- an efficient, 45-50-minute interval workout on the treadmill created by David Siik -- to its athletic training classes last summer. Membership required; multiple locations, equinox.com

 

Mile High Run Club

 

This city's first treadmill-only studio has classes for all levels, from the beginner-friendly 45-minute Dash 28 to the advanced 60-minute The Distance. It also offers outdoor runs, including one led by Olympic runner Michael Stember on Wednesday nights. $34/class; 24 E. Fourth St., 212-466-6472, milehighrunclub.com

 

Orangetheory Fitness

 

Since opening in March, the studio has offered a 60-minute workout that incorporates treadmill training, plus rowing and weight training blocks, that keeps heart rates up while maximizing caloric burn. $34/class; 124 W. 23rd St., 646-588-0133, orangetheoryfitness.com

 

TheRUN

 

The latest treadmill studio offers group classes personalized based on pace, including the 45-minute Shaper and the 60-minute Endurance. $34/class; 24 W. 25th St., 646-682-9076, the-run.com