Book your test.
Know your body.
DEXA body composition, VO2 Max, and RMR — all in one visit.
Scroll down to book your appointmentHow it works
- Pick your test — or bundle several in one visit.
- Choose your day and time.
- Continue to Payment to book.
- Check your email for confirmation and instructions.
Take our 60-second quiz and we'll suggest the right test — or bundle — for your goals.
Take the quiz →repeat body-fat measurements1
in published trial sub-studies2
lowest-fit vs. elite-fit3
and measured RMR4
Choose your test
Book individual tests
or combine them.
Each test delivers a specific, detailed insight. Most clients combine 2–3 tests in a single visit for a fuller picture of their body composition.
DEXA Body Composition Scan
A gold standard for body composition. Measures fat mass, lean mass, and bone density — by region, with high precision (typically 1–2% on repeat measurements). See what your body is made of, not just how much it weighs.
Uses a low dose of ionizing radiation. Bone density values are provided for information and are not a diagnosis.
~8 min Get DexaFit BostonVO2 Max Test
One of the most studied markers of cardiorespiratory fitness and longevity. Walk or run on a treadmill wearing a mask while we measure your aerobic ceiling — so you can track it over time.
A maximal effort test. Tell us about any heart, lung, or blood pressure condition before booking.
~20 min Get DexaFit BostonResting Metabolic Rate (RMR) Test
Formula-based calculators can differ from your measured metabolism by up to ±20%. Breathe into a mask for 15 minutes and get a measured caloric baseline — useful context for your own nutrition planning.
~15 min Get DexaFit BostonBlood Lab Tests
Add a blood panel to your visit for a fuller set of biomarkers alongside your body composition data. Panels are processed through a third-party laboratory.
Quick draw Get DexaFit BostonFull Baseline
DEXA Body Composition Scan + VO2 Max Test + RMR Test in a single appointment. A complete picture of your body composition and fitness in one visit. A great starting point if you want a full baseline to track over time.
Get DexaFit Boston
What our clients say
Rated 5.0 ★ on Google.
"I'd been tracking my weight for years and getting nowhere. The DEXA showed me the breakdown of fat versus muscle. That single insight changed how I think about my training. Loved how clear the report was."
"Getting my VO2 Max number was eye-opening — it gave me something concrete to work toward. I finally had a real baseline to improve from. The whole visit was quick and easy."
"I wanted to track my body composition while on a GLP-1, and the DEXA gave me a clear breakdown. It's now part of my routine every few months. Friendly staff and an easy process."
Unpaid testimonials from individual clients, used with permission. Individual experiences and results vary, and these are not typical or guaranteed results.
Before you arrive
How to prepare for your visit.
Following these guidelines helps keep your results accurate. Deviating can affect the data.
~8 minutes
- Fast for at least 2 hours before your test
- No exercise before — limit activity
- Do not come in dehydrated
- Wear workout clothes without metal (no belts, watches, jewelry)
- Wear socks — you'll be lying on the table
- No contrast medium within 7 days
- Do not scan if you are pregnant or may be pregnant
~20 minutes
- Fast for at least 3 hours (water only)
- No exercise before — limit activity
- Get adequate sleep the night before
- No caffeine or stimulants on the day of your test
- Wear workout clothes and athletic shoes
- Test is done on a treadmill or bike
~15 minutes
- Fast for at least 5 hours (water only)
- No exercise before — limit activity
- Get adequate sleep — ideally test in the morning
- No caffeine or stimulants; no alcohol within 12 hours
- Comfortable clothing — you'll be sitting in a chair
- You'll breathe into a mask for 15 minutes at rest
Quick answers
Common questions.
DexaFit combines detailed body composition testing with data-powered reporting built on over a decade of real-world measurements across 4 continents. Most providers give you a number. We give you a number, what it means, and the context to track it over time.
A DEXA scan uses a very low dose of X-ray radiation — far less than a chest X-ray, and roughly comparable to about a day of natural background radiation. The technology has been used in research and clinical settings for decades and is considered low-risk for most adults.
That said, no radiation exposure is entirely without risk. Do not have a DEXA scan if you are pregnant or think you may be pregnant. If you have specific concerns, or have had recent imaging with contrast, check with your physician before testing.
DEXA: not for anyone pregnant or possibly pregnant, or who has had a barium study, contrast medium, or nuclear medicine scan in the past 7 days. Our scanner also has table weight and scan-area limits — email us if you're unsure.
VO2 Max: a maximal exertion test. If you have a known heart or lung condition, uncontrolled high blood pressure, or have been advised to avoid strenuous exercise, clear it with your physician first and let us know before your appointment.
The DEXA Body Composition Scan itself takes about 8 minutes. VO2 Max is approximately 20 minutes. RMR is 15 minutes of quiet breathing. Most clients doing all three are in and out in about an hour, including check-in and review.
The DEXA Body Composition Scan is a popular choice for GLP-1 users. It shows the breakdown of fat mass versus lean mass — something the scale alone can't tell you. Published sub-studies of GLP-1 trials have reported that a meaningful share of the weight lost was lean mass, so a DEXA helps you see your own breakdown. Combining with RMR adds your measured metabolic baseline.
We provide measurements only — we don't advise on medication, dosing, or treatment. Those conversations belong with your prescribing clinician.
Absolutely — and we encourage it. DexaFit reports use widely recognized body composition technology and terminology. Many clients share their reports with their primary care doctor, dietitian, or trainer to inform their own decisions. Your report is a set of measurements, not a diagnosis.
Most clients test every 3–6 months to track progress. The real value is in the repeat measurement — seeing how your body changes over time as you adjust your training and nutrition. A single test gives you a baseline; re-testing shows your trend. For DEXA, it's also worth keeping cumulative radiation exposure in mind when scheduling repeats.
VO2 Max reflects cardiorespiratory fitness — how efficiently your body uses oxygen during exertion. It's one of the most studied markers of fitness and longevity. RMR measures how many calories your body burns at rest. They reflect different systems and are both useful in the same visit.
Yes. Blood panels can be added to your visit or booked separately and are processed through a third-party laboratory. To view blood panel options click here, or contact us at boston@dexafit.com. Results are issued by the laboratory.
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DexaFit Boston
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Your body is telling
a story right now.
8 minutes. Detailed results. The baseline everything else builds on.
Not medical advice. DexaFit Boston provides body composition, cardiorespiratory, and metabolic measurements for wellness and informational purposes. Our services and reports are not intended to diagnose, treat, cure, or prevent any disease, and are not a substitute for evaluation, diagnosis, or treatment by a licensed healthcare provider. Consult your physician before starting or changing an exercise or nutrition program, and before acting on any measurement in your report. DEXA scanning uses ionizing radiation; do not undergo a scan if you are pregnant or may be pregnant. VO2 Max testing involves maximal exertion and carries inherent risk. Individual results vary.
Sources — verify each before publishing. 1 Reported precision (repeatability) of DEXA for total-body fat measurement; varies by scanner, software, and operator. 2 DEXA sub-studies of GLP-1 receptor agonist weight-loss trials, in which lean mass accounted for a substantial share of total weight lost; proportions vary by trial and population. 3 Mandsager K, et al. JAMA Network Open. 2018;1(6):e183605 — observational cohort of 122,007 patients referred for exercise treadmill testing; adjusted all-cause mortality compared the lowest-performing with the elite-performing group. Findings in a referred clinical population may not generalize. 4 Comparisons of predictive resting-metabolic-rate equations against measured indirect calorimetry; accuracy varies substantially between individuals. Figures on this page describe findings in published studies of other populations and are provided for general educational context only.