About Valence
Your health, fully integrated — and personally guided.
Valence began with a simple observation: the people most disciplined about their work, training, and time often have the least clarity about their own physiology. We built a calm, precise way to change that.
The philosophy
Clarity is the luxury.
The promise of Valence isn’t a miracle or a shortcut — it’s a clear, honest read of where you actually stand, and a named team accountable for acting on it. The managed relationship is the product; measurement is the intelligence layer behind it. We sell management and clarity, not fear and not guarantees.
The work happens in Boston, operated by Back Bay Fit at 400 Commonwealth Ave, as a joint venture between two practitioners who care about doing this precisely.
Measured, not guessed
We start from data — real measurements of your body, your engine, and your blood — not assumptions.
Calm and unhurried
Premium doesn’t mean rushed. Your visit and your readout are given the time they deserve.
Complementary care
We work alongside your healthcare, never in place of it, and we’re clear about that line.
The team
A joint venture, by design.
Valence is a partnership between Back Bay Fit and MoveWithONYX — performance and rehabilitation, under one roof.
Johnny Loreti, MS, CSCS, CPT
Co-founder
Johnny is the founder of Back Bay Fit, a Boston performance and training practice built around measurement — VO2 max, body-composition, and metabolic testing paired with personalized coaching. A strength and conditioning coach and lifelong competitor, he brings a performance-first, data-driven philosophy to precision health.
Dr. Kyle Mahoney, DPT
Co-founder · Physical therapy (MoveWithONYX)
Kyle is a sports-residency-trained Doctor of Physical Therapy and Certified Strength and Conditioning Specialist who owns MoveWithONYX, a Boston-based sports and orthopedic physical therapy practice. He completed his sports physical therapy residency at the University of Southern California and teaches as adjunct faculty at Northeastern University and the MGH Institute of Health Professions.
Dr. Steven Zivich
Physician Partner — Valence Private
Dr. Zivich is a Boston-based, board-certified family medicine physician whose work emphasizes preventive, lifestyle-focused care delivered directly to patients, outside the constraints of the traditional insurance model.
Dr. Paul Heinzelmann
Physician Partner — Valence Private
Dr. Heinzelmann is a Boston-based primary care physician affiliated with Massachusetts General Hospital. With more than two decades in primary and urgent care, his practice centers on small panels, unhurried visits, and evidence-based, lifestyle-focused medicine.
Physician partners: Dr. Steven Zivich and Dr. Paul Heinzelmann. Medical services within Valence Private are provided by independent, licensed physicians; Valence itself is not the licensed medical provider.
The physician-relationship model
A retained physician and an advisor, on the same data.
In most lives, the doctor and the trainer never speak — each works from a fragment. Within Valence Private, a retained physician and your Performance Advisor work from the same diagnostics, in the same quarterly reviews. Clinical findings change the plan; the plan reflects your actual physiology. That shared picture — not any single test or visit — is what changes the experience.
Meet us
Come see how a managed year works.
Explore the memberships, or start with a free discovery call to see if Valence is right for you.
Not sure where to start? Book a discovery call →