First Guess Fitness

First Guess Fitness is a small-group and private personal training studio near Downtown Crossing in Boston, built around structured strength training and habit coaching. Every session is coached and planned in advance so members never have to guess what to do, and the gym leans on scheduling and accountability rather than motivation alone. The environment is meant to be supportive and non-competitive, making strength training feel normal and safe for adults with busy schedules.

The studio was founded by Dr. Justin Kompf, a published exercise scientist, and members often mention him and coach Patrick by name, praising their patience and attention to form. Small class sizes give clients much of the attention of one-on-one training with the consistency and community of a group. For those who cannot train in person, the same programming is offered remotely with check-ins, and a low-pressure online option provides AI workouts, tracking and community.

What to Know

• Training formats include private one-on-one and semi-private coaching.
• New members start with a short call and an intro visit that includes goal and movement assessments plus a mini workout.
• An introductory trial package of sessions is available for newcomers.
• The studio reports about 100 five-star reviews.
• The gym promises zero crowds, setting itself apart from big-box gyms.