A big one. Around fifty fixes across the app. YOUR ADAPTATION CURVE IS MORE ACCURATE. • The curve no longer holds flat for a week after a block and then falls off a cliff. Decay now starts the day after your last night, which is what the research actually shows. • Training sessions at altitude no longer add to your haemoglobin projection. Forty-five minutes is too short to start that response — it needs hours of continuous exposure. If you have logged gym sessions, your projection will drop. It was overstated before. • The chart opens on two years instead of three months, runs sixty days ahead instead of a year, and the grey dashed line now shows where you are heading if you do nothing more. NUMBERS THAT AGREE WITH EACH OTHER • The Recovery arrow no longer says "Falling" about the altitude dip the score beside it has already corrected for. • A projected loss is shown as a loss, not as a green "+0.0%". • "Consistency" can no longer read more nights than your plan asked for, and no longer disappears when you complete every one of them. • Your plan's forecast now says it is a forecast, with its range. LOGGING • Home now has two buttons: log a sleep session, or log a training session. The training one opens straight into interval setup and tells you what that session does — and does not do. • If you have a Box Altitude sensor, the app now checks the night against it properly. It reads your ring's in-bed window first, then the sensor's readings for those hours, and offers to correct what you typed. • Completed training sessions stay in your history instead of vanishing. PLANS • Easy runs are prescribed at the altitude you are sleeping at, not at the plan's final peak. • The Ramp-Up tab shows the actual ramp your plan was built with. • Both wizards tell you the hours a night they are asking for before you commit. A NOTE ON DEMO MODE If you tried the app in Demo Mode before signing up, anything you logged there is offered to your account on first launch — bring it across or start fresh. Sample data left behind by older versions is tidied up, and you will see a note if anything is removed.

Altitude, weight and temperature can now be shown in metric or imperial — set it in Profile → Units, and the Apple Watch follows. The "Is it working?" card now covers a fixed last 30 days, and you can tap it to see exactly which nights were counted, and edit any of them. A night you log is now checked against your Box Altitude sensor, so the altitude on record is what was actually delivered while you were in bed rather than what you set. Fixes: nights covered by more than one entry are no longer counted twice, sensor-detected nights that crossed midnight no longer counted as two, and the Home screen is faster.

• Invite a training partner and you both get a month of Pro, free. Share your code from Profile → Oxygen Circle; when they join and connect a wearable, the month is added to both accounts automatically. • Sharing an invite now includes a download link, so the person you're inviting can actually find the app. • Behind-the-scenes improvements to how subscription access is handled.

Oxygen Coach now has Pro and Elite plans — and if you were already here, Pro stays free on your account. Permanently. Nothing to do, nothing to pay. • Pro and Elite plans. Pro covers full trends history, overnight response detail, the AI Coach, the nutrition stack and the plan wizards. Elite adds manual haemoglobin-mass and iron-panel checkpoints. Both come with a one-week free trial. • Your profile is finally editable. Sex, age, primary goal and weekly training hours can all be changed after setup instead of being locked in during onboarding. • Smarter iron thresholds. You can now record menopause status, and the point at which we flag low iron stores adjusts accordingly — iron needs genuinely change once monthly losses stop. • Clearer science. Several claims across repeated-sprint training, cold exposure and altitude HRV have been reworded to match exactly what the research shows, no further.

A big update since launch: • Recovery that understands altitude — your HRV is now scored against what your altitude predicts, so a normal-for-altitude night reads fair instead of alarming. See your typical range at each altitude, and get a heads-up when your HRV rebounds after a block. • Guided, science-backed sessions — repeated-sprint (RSH) intervals plus sauna, heat suit, cold plunge and HBOT timers, each anchored to the published protocol, with interval mode and save-to-repeat. • Clearer overnight response, haemoglobin-mass tracking, and target-date planning that projects your adaptation before you commit. • Faster morning load and broader wearable support (Oura, Apple Health, Strava). • The full app is now free. Thanks for all the feedback — keep it coming.