For nearly twenty-five years, Arthur Baca has been a trusted presence in the Upper East Side’s fitness community. His clientele has spanned professional sports team owners, celebrated entertainers, industry leaders, international visitors, dedicated amateur athletes, and discerning professionals. Throughout the constant evolution of the fitness landscape, Arthur has found one principle to be unwavering: the transformative power of the trainer–client relationship.

Apartment AB was created to elevate that relationship. Designed as a refined, private training facility, Apartment AB offers a setting where both trainers and clients feel genuinely at home. Here, independent trainers are empowered with the space, resources, and atmosphere needed to help clients achieve their goals—while growing their own business in an environment defined by privacy, security, cleanliness, and understated luxury.

Our facility features premium multi-functional equipment, free weights, mats, TRX, 30 feet of turf, fresh towels, filtered water cooler, well-appointed bathrooms, showers, and secure lockers—everything required to cultivate a seamless, welcoming, and professional training experience.

At Apartment AB, we understand what it takes to support the success of independent trainers. No more corporate gyms where your expertise yields minimal return. No more facilities packed with rows of machines that don’t serve your clients’ needs. No more overcrowded “private” gyms that compromise your sessions. We maintain a strictly limited number of trainers and clients per hour, ensuring a calm, unhurried environment where your work—and your clients—remain the priority.

Framed by expansive windows overlooking Madison Avenue in the heart of the Upper East Side, Apartment AB provides a serene, elevated space where trainers can grow their business and clients can truly thrive.