A maximal CPET is a single morning, but the physiology it reveals should shape every workout, every long run, and every race-day fueling decision for the next six months. Aevox is the app that carries it forward — three pillars tracked across your training, a coach that has actually read your test, and a fueling protocol built from your own numbers.
Free to start, no card. No CPET yet? Sign up anyway — connect your training first and add the lab test when you're ready. We'll help you find a clinic.
Most athletes get a PDF, learn their VO₂max, and never look at those numbers again. Aevox keeps the test alive — anchoring three measurable pillars to your physiology and watching them move as you train.
Your trajectory matters more than any single snapshot. We track the direction your physiology is moving across months, not the number you posted one Tuesday morning.
Every number traces back to an assumption, a citation, and your data. Nothing on your dashboard is a population average wearing your name.
When confidence is low, we say so. When the data can't support a number, we tell you what's missing instead of filling the gap with a guess.
When your test is scored on Aevox, you walk out with more than a VO₂max number. You get substrate oxidation across the spectrum, fatmax and crossover heart rates, training zones anchored to your own VT1 and VT2 — and an interpretation your coach can actually use to write a block.
Your report is your own medical data. Claim it, read all of it, and export it whenever you like — with no subscription and no card. The test tells you where you are; the subscription is for where you're going.
Your CPET interpretation becomes the anchor for a longitudinal profile that pairs the lab numbers with the training you actually do. Three pillars, tracked month over month, every one of them grounded in your own data — and everything else is downstream.
Not just your VO₂max — how well you use fat and carbohydrate at every intensity from easy to maximal. Anchored to the substrate curve measured in your test, then watched as your training changes it.
How efficiently you turn oxygen into speed. We track the cost of holding your goal pace and correct it for grade, heat, and altitude — so a hilly summer block reads as a hilly summer block, not a fitness decline.
Can you hold it together late in a race? We look at how your body responds under sustained effort — the drift between what you were doing at minute 20 and what you're doing at minute 120.
Ask about your physiology in plain language. Pax answers from your measured thresholds, your zones, and your own training history — not from a generic training blog that has never seen your data.
When the confidence behind an answer is low, it says so. When a question needs a human, it routes to your coach rather than improvising.
Answers come from your profile, so they land differently for every athlete — which is why there isn't a sample one printed here.
Free, no card. You don't need a lab test to start — signing up first is a perfectly good order to do this in.
Connect Strava or Whoop, or upload your own export. This is the raw material the pillars are computed from.
Claim the CPET your clinic shares with you — or, if you haven't been tested yet, we'll point you to a partner clinic.
Find a clinic →Three pillars month over month, Pax for the questions in between, and a fueling config that scales with your intensity.
Thresholds, substrate crossover, and fatmax come from a maximal CPET scored breath by breath — not estimated from a wrist optical sensor and a population equation.
Economy is adjusted for grade, heat, and altitude, because otherwise a warm week and a hilly route look exactly like losing fitness. What's left is the part that's actually you.
Metrics carry a confidence level, and low confidence is shown rather than hidden. Where the data can't support a conclusion, the app names the missing input instead of inventing one.
Where we are. The interpretation pipeline was calibrated against Douglas-bag gas collection; formal multi-site validation is a planned next step with our clinic partners, not something we've already banked. Read the methods.
You bought the CPET from a clinic; paywalling the result of it would be both bad ethics and a bad deal. So the test itself stays free forever, and the subscription covers everything longitudinal — the part that only exists because you kept training after the lab.
Everything the test produced, and the ability to walk away with it.
The longitudinal product. 7-day trial, no card up front.
Your seven days begin when you have something to look at — the moment you claim a CPET or your first training data lands. A trial spent staring at an empty dashboard isn't a trial, so the clock doesn't start at signup.
Nothing automatic — there's no card on file to charge. Your report, your lab history, and your export stay exactly where they were; only the longitudinal surfaces wait for a subscription.
Fyool turns your Aevox test into an endurance fuel you actually mix and drink. Your carbohydrate burn rate, your substrate ratio, and your electrolyte losses determine a personal maltodextrin-to-fructose ratio, concentration, and sodium profile — formulated from real metabolic data, not a marketing department's best guess.
Create your account, bring whatever data you already have, and see what your training is actually doing to you. Free to start, $20 a month when you want the trajectory.
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