Guides
A score tells you what happened. These are about why — written plainly, and honest about the places where the evidence is genuinely mixed rather than only about the places where it is convenient.
Why two devices give different deep sleep numbers for the same night, and which parts of the reading are worth acting on.
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The post-lunch dip appears in people who ate nothing. What actually causes it, and why it lands at a different hour for different people.
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What the research found, where it is genuinely contested, and the intervention that costs nothing and takes five minutes.
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A busy road costs less than one audible conversation. Why speech is the expensive kind of noise, and what helps.
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The shift to a later body clock at puberty is biological and measurable. What helps when the timetable will not move.
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The most over-interpreted number on any wearable. Why comparing yours to anyone else is meaningless.
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Almost nobody knows they do it until a dentist says so. Why the jaw is loud to a forehead sensor and invisible to a wrist.
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A horse can doze standing but cannot reach REM without lying down. Why recumbency matters and what stops it.
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