I Stayed Awake 24 Hours - Here's the Data

What really happens to your brain and body when you skip a whole night of sleep? In this illustrated book, John Lemuir stays awake for 24 hours with no caffeine, wearing a heart-rate strap, a continuous glucose monitor and an EEG headband, and takes a reaction-time test every few hours.

You follow the experiment hour by hour. In hours 0 to 8, tiredness still feels manageable. In hours 8 to 16, focus comes in waves and the evening dip arrives. In hours 16 to 24, the brain starts taking short breaks on its own, and a false second wind makes things feel better than they are. Then the book shows what each sensor really measured, what the morning after looked like, and what one personal experiment can and cannot prove.

The central finding is simple and useful: feeling awake and performing reliably are not the same thing. The book also explains the research showing that 24 hours awake impairs performance about as much as a 0.10% blood-alcohol level, and gives clear, practical advice for the day after a sleepless night.

Thirty-nine pages, with 21 illustrations and photographs, 17 tables and 5 charts, plus a one-page summary for every chapter, ten key takeaways, a glossary and a further reading list.

Based on the SleepMetric YouTube video "I Stayed Awake 24 Hours - Here's the Data." For general education, not medical advice. Please do not repeat this experiment. Instant PDF download. By John Lemuir.