At Onyx the test is run on a treadmill or a bike with a metabolic cart that analyses every breath. It takes about forty-five minutes including the warm-up, the test itself lasts ten to fourteen minutes, and the report is explained to you before you leave.
What the test gives you
Three numbers matter. Your VO2 max, in millilitres of oxygen per kilogram of bodyweight per minute, tells you the size of your engine. Your first ventilatory threshold marks the intensity below which you can train for hours and recover quickly. Your second ventilatory threshold marks the intensity above which fatigue arrives in minutes.
From those two thresholds we set your heart-rate and pace zones. Training in the right zone for the right reason is what moves the number; most people who plateau train too hard on their easy days and too easy on their hard days.
How the test runs
You arrive rested, two hours after your last meal, in running or cycling clothes. After a warm-up the speed or the resistance rises in small steps every minute while you breathe through a mask. The test ends when you stop, and the coach watches the heart rate and the breathing the whole way.
The report is in your account in the app the same day: the VO2 max, the thresholds, the zones and a comparison with the last test if you have one.
Who books it
Runners, cyclists and triathletes preparing for a race, athletes whose sport has an endurance base, and adults who want a real number for their fitness. It is $249, paid when you book, on an open time with a coach.