Yuki Tanabe
Checks the arithmetic before a piece ships: what the chart is actually plotting, whether the effect size survives the confidence interval, and whether a pooled figure is being passed off as a measurement. Every source line under every chart on this site went past this desk. Writes the pieces that are mostly numbers.
Statistics · Charts · MethodologyOsakaHere since September 2025
Written by Yuki
- Does the Apple Watch have a readiness score?Blog · Aug 2026
- The Apple Watch Vitals app, explainedBlog · Aug 2026
- Are Apple Watch HRV readings accurate?Blog · Aug 2026
- Does WHOOP sell your data?Blog · Aug 2026
- How recovery scores actually workBlog · Jul 2026
- How to measure body fat with a tape measureGuide · Jul 2026
- Your Resting Heart Rate Knows FirstDeep dive · Jul 2026
- Baselines & confidenceDocs
- ExperimentsDocs
Reviewed by Yuki
- Body Battery for Apple WatchBlog · Aug 2026
- How to export your WHOOP dataBlog · Aug 2026
- Apple Watch HRV not showingBlog · Aug 2026
- Strain score on Apple WatchBlog · Aug 2026
- Why is my HRV low?Blog · Aug 2026
- Apple Watch Sleep Score, explainedBlog · Aug 2026
- How long caffeine actually affects your sleepBlog · Aug 2026
- Oura Ring not chargingBlog · Aug 2026
- How to delete your Oura accountBlog · Aug 2026
- Apple Watch hypertension notificationsBlog · Aug 2026
- WHOOP vs Oura RingBlog · Jul 2026
- Why your wearable has no idea which muscles are tiredBlog · Jul 2026
- The Cooper Test: measure your VO₂max in 12 minutesGuide · Jul 2026
- How to improve your HRVGuide · Jul 2026
- The Shape of the TaperDeep dive · Jul 2026
- Recovery scoreDocs
- The sleep-anchored dayDocs
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