Methodology
What the MaxDex Energy Model Cannot Do
Every measurement product has boundaries. Most bury them. This page states ours plainly, because a number you can calibrate your trust against is more useful than one you cannot.
What does MaxDex not measure?
Short answer
No heart rate, no heart-rate variability, no blood oxygen, no skin temperature, no respiratory rate. On iPhone the app requests exactly two things from Apple Health: step count and sleep. Everything else is either logged by you or inferred from phone signals.
This rules out a direct comparison with wearables on biometric depth, and we would rather draw that line ourselves than have it drawn for us. If a recommendation depends on autonomic state — recovery scores driven by overnight HRV, for instance — MaxDex is not measuring the thing that produces it.
What follows from the narrow permission scope is a privacy property worth stating: an app that never requests heart rate cannot leak it.
Is MaxDex a clinical or medical tool?
Short answer
No. MaxDex is a software productivity application, not a medical device. The model is built on peer-reviewed scientific frameworks (Borbély’s two-process sleep model and Banister’s systems model) adapted for daily schedule planning.
The mathematical foundation relies on established peer-reviewed models: Borbély’s two-process model of sleep regulation and the Banister fitness-fatigue systems model. The constants, weights, and curves are designed for practical daily energy forecasting rather than clinical diagnostics.
MaxDex does not claim to replace clinical health assessments or wearable telemetry, and outputs should be used to guide personal productivity and daily follow-through.
Sources
- Borbély, Daan, Wirz-Justice & Deboer (2016). The two-process model of sleep regulation: a reappraisal. — Journal of Sleep Research
- Calvert, Banister, Savage & Bach (1976). A Systems Model of the Effects of Training on Physical Performance. — IEEE Transactions on Systems, Man, and Cybernetics
Related
Is anything in the model switched off?
Short answer
Yes. The cognitive driver, intended to capture screen and cognitive load, currently returns no value and contributes exactly zero to your score. Its weight appears in the model but has no effect today.
Screen-time input is wired out of the app and the algorithms. The scaffolding remains, including a re-centring baseline constant so that enabling it later does not create a sudden discontinuity in everyone’s history.
Relatedly, the engine computes a richer blended "mental energy" curve that the interface does not show. Until screen time ships, mental energy is presented as the sleep score alone, so that the app and the AI never quote two different numbers for the same question.
What can a phone genuinely not detect?
Short answer
Sleep stages. Phone-only detection produces duration, efficiency, disturbance and awake minutes — not REM, deep or light sleep. It also cannot detect sleep at all if the phone is not with you.
The data model can store staging when a platform provides it, but nothing in the phone-only path produces it. Any product claiming phone-only REM detection is describing something its sensors cannot support.
Detection quality also degrades in specific, predictable ways: a phone left on a desk overnight, a night of heavy phone use in bed, or a device that dies. These produce low-confidence readings, which the model then regresses toward your baseline rather than treating as fact — see how uncertain nights are handled.
Is MaxDex a medical device or an ADHD treatment?
Short answer
No to both. MaxDex is productivity software. It does not diagnose, treat, cure or prevent any condition, including ADHD and executive dysfunction, and no output should be used as a clinical signal.
Many people who use the app describe ADHD-related task paralysis, and the product is designed with that experience in mind. Designing for an audience is not the same as treating a condition, and we do not conflate the two.
If sleep or energy problems are persistent or severe, that is a conversation for a clinician, and a productivity app is not a substitute for one.
What happens when there is not enough data?
Short answer
The app says so. A date with no logged data returns a neutral 50 explicitly flagged as having no data, and the interface is gated so a bare circadian default cannot be presented as a real reading or forecast.
This is a deliberate design decision with a visible cost: a new user sees an empty state instead of an impressive-looking chart. An invented number is worse than an honest gap, because it teaches you to trust a reading that means nothing.
The same principle governs the forecast band, which widens from ±3 to ±30 points as it projects further out, and the confidence weighting that pulls uncertain nights toward your baseline instead of letting them swing the score.
Frequently asked questions
Is the energy score intended for medical diagnostics?
Can MaxDex diagnose or treat ADHD?
Why does the app show no score instead of estimating one?
Will the screen-time feature ever be enabled?
Last reviewed August 28, 2026 by the MaxDex Services team. How we research and review this.