A VO2 max test measures the maximum amount of oxygen your body can take in, transport and use during exercise, expressed in millilitres per kilogram of bodyweight per minute (ml/kg/min). You breathe through a mask connected to a metabolic analyzer while the effort on a treadmill or bike ramps up until you reach your limit. It is the gold-standard measure of aerobic fitness and the basis for setting personal heart-rate training zones.

Active metabolic rate is how many calories you burn at increasing exercise intensities. It's measured in the same test as VO2 max, which is why the report also gives you calories burned per minute in each heart-rate zone and the intensity at which you burn the most fat versus carbohydrate.

An RMR (resting metabolic rate) test measures calories burned at complete rest — your baseline for nutrition targets. A VO2 max / AMR test measures capacity and calorie burn during exercise — your baseline for training. Many clinics offer both; together with a DEXA scan they give a complete metabolic and body-composition picture.

No. Wearables estimate VO2 max from pace, heart rate and algorithms; this test measures the oxygen you actually consume. Estimates are commonly 5–15% off, and any training zones your watch derives from that estimate inherit the error. Many people bring their watch and have the measured zones programmed in after the test.

It depends on age and sex. As a rough guide, average is roughly 35–40 ml/kg/min for men and 27–31 for women in their 40s; recreational endurance athletes often test in the 45–55 range and elite endurance athletes 70+. Your report shows where you rank for your age and sex — and the goal is to move your own number, not hit someone else's.

Cardiorespiratory fitness is one of the strongest single predictors of long-term health and all-cause mortality — stronger than most traditional risk factors. Moving from a low to a below-average VO2 max is associated with a large reduction in risk. That's why longevity-focused clinicians test it and why adults 40+ are one of the fastest-growing groups booking it.

Untrained adults often see 10–20% improvement in 8–12 weeks of consistent training that includes interval work; trained athletes improve more slowly. Retesting on the same equipment is the way to confirm the change is real.

Plan on 45–60 minutes. That includes set-up, a warm-up, 8–15 minutes of actual testing as the effort ramps up, cool-down and a debrief where your zones and calorie-burn curve are explained.

Arrive rested (no hard workout in the previous 24 hours), well hydrated, and 2–3 hours after your last meal. Skip caffeine, alcohol and nicotine for at least 3 hours before. If you take beta-blockers or other heart-rate-affecting medication, tell the clinic when you book.

It's a lightweight silicone mask that seals around your nose and mouth and connects to a hose; you can breathe normally through it. It takes a minute to get used to and most people forget it's there once the effort picks up.

Instead of a formula like 220-minus-age, zones are anchored to two points the analyzer detects in your breathing: the aerobic threshold (where you start relying more on carbohydrate) and the anaerobic or ventilatory threshold (where effort becomes unsustainable). Zones built on those points reflect your physiology, not a population average.

Yes. The report gives heart-rate ranges (and often pace or power ranges) that map directly onto custom zone settings in Garmin Connect, Apple Fitness, Zwift, TrainingPeaks and most coaching platforms.