New York is full of unorthodox hybrids: Laundromat-cafés, Chinese-Mexican restaurants, childhood enrichment center-day spas. The city’s latest hyphenated identity is a salon-fitness center, a new joint venture from hairstylist Julien Farel and personal trainer Pete Kupprion.

In recent years, Mr. Farel, an alumnus of Frédéric Fekkai who founded his own eponymous salon eight years ago, was looking to expand his brand. An obvious answer would have been to open a satellite salon or to launch a proprietary line of hair-care products. But Mr. Farel, whose wife had been a client of Mr. Kupprion’s, took a different tack: He decided to start a personal-training gym and wellness center atop his two-story salon and recruited Mr. Kupprion as his partner.

“The idea is that you can work out and then go downstairs for a manicure or a blow-dry, and you’re ready for the workday, or a night out,” Mr. Farel, who grew up on the outskirts of the French city of Lyon, said. He explained that he and Mr. Kupprion, who also runs a small gym inside a Wall Street brokerage firm, share a vision for maintaining a singular level of customer service in an intimate, boutique-like space.

JF Gymnastique, which opened on Madison Avenue at 57th Street this spring, is steadily increasing its client base, including the real estate scion and executive Ivanka Trump, who is a new member.

The fitness center is situated in a tidy 1,000-square-foot space outfitted with exercise machines and hand weights. It also has two suites that resemble physician exam rooms; there, a team of chiropractors, acupuncturists, soft-tissue specialists, massage therapists, and nutritional counselors offer a range of à la carte services to complement clients’ workout routines.

In addition, Mr. Kupprion, who studied under the supervision of osteopaths, incorporates into his training regimens techniques such as myofascial stretching, a form of soft-tissue therapy; and pompage, a manual pumping of the joints that is sometimes used to treat sports injuries.

A longtime salon client, Steven Black, recently began working out twice a week at JF Gymnastique, where he also takes advantage of its on-site massage, chiropractic, and nutrition services. “I’m there every two to three weeks for a haircut anyway, so it was very convenient,” Mr. Black, who works on Wall Street, said.

“He spots you, he corrects everything you do, he pushes you just enough,” he said, crediting Mr. Kupprion with helping him drop 3 inches from his waist, dramatically improve his posture, and reduce his neck pain.

A visit to JF Gymnastique requires an appointment with Mr. Kupprion or one of his associates. As a result, the fitness center is not likely to draw clients who value the flexibility of being able to stop in and out of a gym during an unexpected hour of downtime, or those who like the wide range of group exercise classes offered at any number of larger chain gyms throughout the city.

But the facility may hold a special appeal to people looking for one-on-one training in a discreet, semi-private setting. There are never more than three clients working out — each with a personal trainer — at the same time. The only group offerings at JF Gymnastique are Vinyasa-style yoga and mat-based Pilates, for which classes are capped at four people.

Upon arrival, each client receives a key to a private locker room, replete with Frette towels and bath and body products from Phyto and Roger & Gallet.

I met with Mr. Kupprion recently for an hour-long workout, which began with some shoulder-opening exercises, done while lying on a foam cylinder. He then led me through a series of challenging mat- and machine-based stretches and exercises, such as squats, rowing, and modified push-ups. What was remarkable was not necessarily the movements — many of which I had done variations of in other settings — but the trainer’s high level of attentiveness to my posture, positioning, and imbalances. His adjustments allowed me to get incrementally more out of each repetition.

After the session, Mr. Kupprion sent me an e-mail, detailing the mat-based routine that he said would supplement all the running I had been doing in preparation for a 10-kilometer race — and help prevent common training injuries. The e-mail included photographs of each exercise, annotated with position-specific instructions such as “the heel of the front foot must be farther forward than the knee” and “increase tension by lightly pushing toward the opposite big toe.”

“It’s about putting the body in perfect balance — about serving the client’s needs from the moment they walk in the door until the moment they leave,” Mr. Kupprion said.

gbirkner@nysun.com