Something wrong? Tell a person.

Darwin reads completed workouts from Apple Health, so the first thing to check is that the workout actually reached Health: open the Health app, go to Browse → Activity → Workouts, and look for the session there. If your watch or head unit hasn't synced yet, Darwin can't see it either.

If it's in Health but not in Darwin, check permissions: iPhone Settings → Health → Data Access & Devices → Darwin, and make sure Workouts, Sleep, Heart Rate and Heart Rate Variability are on. Then pull to refresh on the Training tab. Still stuck? Send me the workout type, its date, and which app recorded it.

This one is real and it isn't your fault. Whoop records HRV as RMSSD; Apple Health stores HRV as SDNN. They are different measurements, so Whoop's HRV never arrives in Health in a form Darwin can read. Apple Watch and Oura both write SDNN and work fine.

Darwin says so on the recovery screen rather than quietly showing you a worse readiness number. Sleep and resting heart rate from Whoop still come through normally.

No — that's the failure mode Darwin was built to avoid. A missed week doesn't get carried forward as debt. The engine re-ramps from where you actually are: it cuts volume, drops lower-priority sessions and intensity first, and caps the coming week so you can absorb it. There's a floor at 60% of what was planned, so one bad week can't spiral into a collapsed block.

Yes, and it behaves differently on purpose. Mid-week, the check-in gives you a preview: it only assesses the days that have come due, leaves next week untouched, and withholds a verdict on your race goal until enough of the week has been assessed to say anything honest. After Sunday, the same check-in commits — full week assessed, weeks ahead rebuilt.

No. Every training-load decision comes from a deterministic, rule-based engine — same inputs, same plan, every time — with hard limits that are unit-tested. A language model is used for exactly one thing: writing the plain-English summary of what the engine already decided. It never sets a session, a load or a target.

No. Raw workouts, heart-rate and HRV streams, individual sleep records and GPS routes are read from Apple Health, used on your phone, and stay there. What leaves your device is your plan (so a lost phone doesn't cost you your training) and a small structured weekly summary used to write your digest — adherence, goal status, three flags, the adjustments made, your event and week number. The full detail is in the privacy policy.

Not today. Darwin leans heavily on Apple HealthKit for the data that drives the weekly rebuild, and there is no equivalent on the other side that works as well. If enough people ask, that changes the maths — so if you want it, say so in the ideas form below and it gets counted.

Not yet, and I'd rather say so plainly than imply otherwise. Sessions come with duration, distance, zone and heart-rate targets you follow on your own head unit. Device push is the most-requested thing on the list.

Cancel from Account → Manage or cancel in the app, or iPhone Settings → your name → Subscriptions. There's no retention flow and no email required. You keep access until the end of the period you've paid for.

Refunds are handled by Apple, not by me — request one at reportaproblem.apple.com. If the app failed you, email me and I'll support the request.

If your subscription lapses, your current week and everything you've already completed stay fully readable. What pauses is the weeks ahead, the weekly re-plan and the digest. Nothing is deleted.

In the app: Account → Delete account. It's immediate and permanent. If you can't get into the app, use the account deletion page and I'll do it for you within seven days.