Body composition testing has moved out of research labs and into performance training — and the two most useful tools for most people are the DEXA scan and the VO₂ Max test. Custom Fit SF offers both — and as of 2025, both are included unlimited with all personal training, partner training, and Tier 2 gym memberships.

What Is a DEXA Scan and What Does It Measure?

DEXA — Dual-Energy X-ray Absorptiometry — uses two low-dose X-ray beams to differentiate between lean tissue, fat tissue, and bone. It's the clinical gold standard for body composition analysis, more accurate than bioelectrical impedance (handheld or scale-based) and more detailed than hydrostatic weighing.

A DEXA scan at Custom Fit SF will show you:

• Total body fat percentage
• Regional fat distribution (visceral fat, android/gynoid ratios)
• Lean soft tissue by region
• Bone mineral density
• Changes across all of the above over time

The regional breakdown matters. Visceral fat — the fat stored around your organs — carries significantly more metabolic risk than subcutaneous fat. A bathroom scale gives you one number. A DEXA scan tells you what that number is made of and where it lives.

What Is a VO₂ Max Test and Why Does It Matter?

VO₂ Max measures the maximum volume of oxygen your body can use during intense exercise. It's the most objective measure of cardiovascular fitness available, and it's one of the most predictive biomarkers for long-term health outcomes.

Research published in JAMA and other peer-reviewed journals has found that low cardiorespiratory fitness is associated with significantly higher all-cause mortality risk — comparable to traditional risk factors like smoking or high blood pressure. Improving your VO₂ Max isn't just about athletic performance. It's about how long you're likely to live and how functional you'll be while doing it.

At Custom Fit SF, your VO₂ Max result is used to set precise training zones — eliminating the guesswork around intensity that leads most self-directed athletes to train too easy on hard days and too hard on easy days.

Why Unlimited Testing Changes Everything

Most San Francisco gyms offer DEXA or VO₂ Max testing as an add-on — $75 to $150 per scan, available once or twice a year. The problem is that one test tells you where you are. Repeated tests tell you whether what you're doing is working.

Custom Fit SF's decision to include unlimited DEXA and VO₂ Max testing with memberships changes the role of these tests. Instead of a periodic snapshot, they become a continuous measurement system. Your trainer sees the data change, adjusts the program, and the next test validates whether the adjustment worked.

Eligible Custom Fit plans include repeat testing so you can review changes with your coach and adjust your program. Schedule reassessments according to your goals and the testing team’s guidance.

What to Expect at Your First DEXA and VO₂ Max Appointment

DEXA: The scan itself takes under 10 minutes. A Registered Dietitian or Exercise Physiologist performs the scan and reviews the results with you. Follow the preparation instructions provided when booking.

VO₂ Max: You exercise while wearing a mask that measures oxygen use as intensity increases. Allow approximately 45–60 minutes for the full appointment, including setup, the exercise test, cooldown and results review.

Combined With Bloodwork and Dietitian Review

For members pursuing more comprehensive diagnostics, Custom Fit SF offers advanced bloodwork panels reviewed by a registered dietitian — including markers for metabolic health, inflammation, hormones, and nutritional deficiencies. This bloodwork layer, combined with DEXA and VO₂ Max data, gives a full picture of where your body is and what it needs.

The Longevity Blueprint — Custom Fit's flagship diagnostic package — combines DEXA, VO₂ Max, advanced bloodwork, Nutrigenomix genetic testing, and a dietitian consultation into one structured assessment.

The $1,250 Longevity Blueprint includes one DEXA scan, one VO₂ max test, advanced bloodwork, Nutrigenomix genetic testing, and a 30-minute Registered Dietitian review.

Getting Tested in San Francisco

Custom Fit offers DEXA scans and VO₂ Max testing at 323 Octavia Street in Hayes Valley, San Francisco. DEXA is not offered at the Market Street studio. Testing is available to members and non-members; eligible personal training, partner training and Tier 2 gym plans include unlimited DEXA and VO₂ Max testing. Book an appointment with the testing team.

Schedule your DEXA or VO₂ Max test →