The longevity space has a signal-to-noise problem. Between continuous glucose monitors marketed to people with no metabolic dysfunction, supplement stacks with weak evidence, and biohacking protocols based on n=1 self-experimentation, it's genuinely difficult to know what's worth doing.
The tests that have the strongest evidence behind them are also the least glamorous: body composition, cardiovascular fitness, blood biomarkers, and genetics. Custom Fit SF has built its diagnostic offering around exactly these — and made them more accessible than any clinic in San Francisco.
The Four Pillars of Meaningful Longevity Testing
1. Body Composition (DEXA Scan)
Lean muscle mass is one of the most protective variables in healthy aging. Sarcopenia — age-related muscle loss — is associated with increased mortality, falls, metabolic dysfunction, and reduced independence. Knowing your lean mass baseline, and tracking whether you're building or losing muscle over time, is foundational.
DEXA also provides visceral fat measurements, which are more predictive of cardiometabolic risk than overall body fat percentage. This single scan delivers more clinically useful data than most annual physicals.
2. Cardiorespiratory Fitness (VO₂ Max)
VO₂ Max is the single best predictor of long-term health outcomes available to a non-physician. Multiple large-scale studies have found that cardiorespiratory fitness predicts all-cause mortality more strongly than traditional risk factors, including hypertension, smoking, and diabetes.
The good news: VO₂ Max is highly trainable. Unlike genetics, it responds dramatically to structured aerobic and interval training. But you need to know your number to know how hard to push and whether your training is working.
3. Advanced Bloodwork
A standard annual blood panel — CBC, basic metabolic panel, maybe a lipid panel — misses most of what matters for longevity. Relevant markers include:
- Apolipoprotein B (a better cardiovascular risk marker than LDL-C alone)
- Fasting insulin and HOMA-IR (early metabolic dysfunction)
- hsCRP (systemic inflammation)
- Homocysteine (cardiovascular and neurological risk)
- Vitamin D, B12, ferritin (common deficiencies with real downstream effects)
- Hormone panels (testosterone, DHEA-S, IGF-1)
Custom Fit SF's advanced bloodwork panels are reviewed by a registered dietitian who translates the numbers into actionable nutrition and lifestyle recommendations — not a PDF of reference ranges.
4. Genetic Testing
Genetics inform, but don't determine. Knowing whether you carry variants that affect fat metabolism, cardiovascular risk, recovery capacity, or vitamin processing allows your training and nutrition protocols to be tailored in ways that generic programs can't achieve. Custom Fit's genetic testing is interpreted in context — alongside your bloodwork, body composition, and fitness data — not as a standalone report.
The Longevity Blueprint: All Four in One Package
Custom Fit SF's Longevity Blueprint combines DEXA scan, VO₂ Max test, advanced bloodwork, genetic testing, and a registered dietitian consultation into a single structured assessment. The output is a complete baseline — a documented, data-rich picture of where you are — and a clear set of priorities for your training, nutrition, and recovery.
This is the starting point for anyone serious about optimizing for the long term rather than the next 12 weeks.
Why a Performance Studio, Not a Clinic
Most longevity clinics in San Francisco are medical environments. The testing is excellent; the follow-through on fitness and nutrition is often limited. Custom Fit SF sits at the intersection of diagnostic precision and applied training — the testing informs the program, and the program is delivered by coaches who understand the data.
The result is a feedback loop that clinics can't offer and most gyms can't support: test, train with purpose, retest, adjust.
Who This Testing Is For
- People in their 30s–50s who want a clear picture of where they stand before problems emerge
- Athletes and high performers who want to train with more precision
- Anyone who's received inconclusive or incomplete results from standard annual physicals
- People who've read Outlive or similar frameworks and want to actually implement them
Where to Get Longevity Testing in San Francisco
Custom Fit SF offers all longevity testing at its Hayes Valley studio (1844 Market St) and Downtown SF location. The Longevity Blueprint package and individual tests are available to members and non-members.