DexaFit Seattle

A good detective builds a case from more than one witness.

The scale and a watch each provide useful accounts of progress. DEXA, RMR, and VO2 testing add information from different systems inside the same body.

DEXA describes body composition, while RMR measures resting energy use. A graded VO2 test evaluates cardiorespiratory fitness and observed thresholds.

The value of comprehensive testing comes from seeing those results together. They can shape the priorities for nutrition and cardio training while giving the next retest a clear question to answer.

This carousel introduces the three witnesses and shows what each one adds to the case.

Save it for your next planning conversation or book comprehensive testing at https://www.seattle.dexafit.com/

A calorie equation works a lot like a weather forecast.

It combines the information available, applies a model, and gives you a reasonable starting point. For resting metabolism, common equations use inputs such as age, s*x, height, and weight.

Mifflin-St Jeor is one of the most respected equations in nutrition practice. Its estimate still describes the result of a model.

In a 2022 study of adults age 65 and older with obesity, 43.1 percent of Mifflin predictions fell within 10 percent of resting metabolic rate measured by indirect calorimetry. Every equation evaluated in that study had an accuracy rate below 60 percent for that specific population.

That sample has clear limits, and other populations can produce different accuracy results. The study shows why a measured RMR can be valuable when nutrition decisions depend on a more individual starting point.

Think of measured RMR as the local reading you use alongside the forecast.

RMR testing measures oxygen consumption and carbon dioxide production at rest to estimate your current resting energy expenditure.

Book RMR or comprehensive testing at https://www.seattle.dexafit.com/

Two people can weigh exactly the same and have very different bodies.

The scale gives you one number: total weight. It cannot tell you how much of that weight is muscle, how much is fat, or where that fat is stored.

Where it is stored matters.

Visceral fat sits deep inside the abdomen around your organs. It is more metabolically active than the fat beneath your skin, and higher levels are associated with greater cardiometabolic risk. You can look relatively lean and still carry more visceral fat than you realize.

A DEXA scan gives you a detailed picture of your body composition.In one quick, low-dose X-ray scan (about the same radiation as a 90-minute flight ✈️), it maps your muscle, bone, and fat while providing an estimate of the visceral fat that a scale and mirror cannot show you.

At DexaFit Seattle, we treat two pounds of visceral fat as an important action point. There is no magic line where risk suddenly switches on, but once visceral fat reaches that neighborhood, it is a number we do not ignore.

The good news is that once you can see it, you can work on it. A retest can then show you whether your plan is actually moving the number in the right direction.

If you are new to DexaFit Seattle, our $99 New Client Special is the easiest way to get your first scan and see what your weight is really made of.

Book through our website or the link in our bio.

A 2025 randomized trial gave the scale and body-composition imaging the same five weeks to report on.

Fifty-eight adults with class 1 obesity were assigned to wear either a high-load vest equal to 11 percent of body weight or a low-load vest equal to 1 percent. Participants were asked to wear the vest for eight hours a day over five weeks.

Body weight remained similar between the groups. The body-composition results added more detail: compared with the low-load group, the high-load group showed a reduction in fat mass and an increase in lean mass, along with a smaller waist circumference.

This was a short, single-center study with a specific population and an unusual intervention. Its best use here is as an interesting result from a tightly defined setting. Weighted-vest decisions still require individual safety and professional context.

The useful marketing lesson is simpler than the intervention. Stable body weight can accompany meaningful shifts in what that weight is made of.

When the goal involves fat mass or lean tissue, DEXA gives the follow-up conversation the detail it needs.

Book DEXA or comprehensive testing at https://www.seattle.dexafit.com/

Two people each lose 30 pounds on Ozempic. The scale says they tied.

They didn't.

In published studies, somewhere between a quarter and 40 percent of the weight lost on GLP-1 medications came from lean mass, which mostly means muscle.

Run that math on 30 pounds: at the low end about 7 pounds of muscle are gone, at the high end closer to 12. One person kept the tissue that protects metabolism, strength, and bone for the next 30 years. The other paid for their weight loss with it.

Same prescription, same scale. Very different bodies at the end.

To be fair to the medications: any rapid weight loss can do this, aggressive dieting included. GLP-1s just made losing weight fast far more common.

The scale cannot tell you which of those two people you are. A DEXA scan can. Twenty minutes, low-dose, and it shows exactly what your loss is made of: fat, muscle, bone. With that picture, you and your doctor can adjust protein and strength work while the weight is still coming off, which is when it's cheap to fix.

If you're on one of these medications and have never measured your body composition, this is the moment. Your first DEXA at DexaFit Seattle is $99 with the New Client Special, and we review the results with you so every number makes sense.

Book at seattle.dexafit.com.

Heart-rate zones become more useful after the session has a purpose.

An easy aerobic session, threshold-focused work, and high-intensity intervals ask the body to solve different problems. The best intensity depends on the adaptation you are trying to create, the person's current fitness, and how the session fits the rest of the week.

Zone 3 deserves context here. Moderate work can be useful for many goals. For athletes focused on raising their aerobic ceiling, the planning issue is the habit of drifting into the moderate gray zone by default. That pattern can make recovery days more demanding while reducing the quality available for truly hard sessions.

This carousel gives each major cardio session a job description so intensity follows purpose.

Save it for your next training week. For a deeper guide to thresholds and personalized zones, comment CARDIO and I'll send over the guide.

If cardiorespiratory fitness had a campaign for becoming a vital sign, this study would be one of its strongest advertisements.

Cleveland Clinic researchers examined 122,007 consecutive patients who completed symptom-limited treadmill testing between 1991 and 2014. During follow-up, 13,637 deaths occurred across 1.1 million person-years of observation.

Higher estimated cardiorespiratory fitness was associated with lower long-term all-cause mortality across the performance groups. The highest fitness group had the lowest adjusted mortality in the analysis.

As an observational cohort of patients referred for treadmill testing, the study supports association language. Causal effects require intervention studies designed for that question.

It still makes a compelling case for knowing where your fitness stands and tracking how it changes over time.

VO2 testing gives cardiorespiratory fitness a number you can train, retest, and discuss alongside the rest of your health picture.

Book VO2 or comprehensive testing at https://www.seattle.dexafit.com/

A small exercise study produced a result worth looking at closely.

Researchers compared two ways of setting aerobic training intensity over 12 weeks: ventilatory-threshold data and percentages of heart-rate reserve.

Among the 24 participants included in the responder comparison, all 12 people in the threshold-based group improved relative VO2 max beyond the study's response cutoff. Five of 12 did so in the heart-rate-reserve group.

The result supports a useful idea: people may receive a more consistent training stimulus when intensity is connected to observed physiological thresholds.

The sample was small, and the groups may also have experienced different training intensities. The result gives researchers a useful question to test in larger, well-controlled trials.

For someone planning cardio today, the practical value is straightforward. A percentage formula offers a starting point. Threshold testing can add a more individual map of the effort.

Commen𝘁 𝗖𝗔𝗥𝗗𝗜𝗢 𝗳or the free guide.

Her watch provided useful heart-rate data through a zone boundary based on prediction.

Imagine an athlete whose wearable labels a steady run as Zone 2. During a VO2 test, her breathing and gas-exchange pattern places the first ventilatory threshold at a lower heart rate.

Wrist-based heart-rate data can be valuable for tracking effort and repeatability. The label attached to that heart rate depends on the zone model, the device settings, and the personal information available to the algorithm.

A VO2 test adds observed physiological landmarks. As exercise intensity rises, the test tracks oxygen use, carbon dioxide production, ventilation, and heart rate together. Those changes help identify where VT1 and VT2 occur during the test.

The watch now has better context. The athlete can use the same familiar device with zones connected to her measured response.

Want a clearer explanation of zones, thresholds, and wearable data? Comment 𝗖𝗔𝗥𝗗𝗜𝗢 and I'll send you the Cardio Without Guesswork guide.