Sleep

Sleep isn't a luxury or a productivity hack — it's the master regulator of almost every system in the body. Poor sleep sabotages weight loss, drives insulin resistance, lowers testosterone, damages memory, and shortens lifespan. Fix sleep and a dozen other problems start solving themselves. This chapter is arguably the most important in the book.

6 takeaways from this chapter.

• Sleep architecture decoded — what deep sleep, REM, and light sleep each do, and how to measure them
• Why sleep tracking devices have transformed what's possible for anyone serious about optimisation
• The circadian foundations — light exposure, meal timing, temperature — most sleep advice skips
• How common medications (SSRIs, beta-blockers, alcohol) wreck sleep quality even when duration looks fine
• The role of peptide and nutritional support in restoring damaged sleep architecture
• When and how to investigate sleep apnoea — the single biggest under-diagnosed sleep problem

Anyone waking up tired no matter how many hours they log. People whose sleep fell apart in perimenopause, after a stressful period, or with age and never quite came back. High performers who know better sleep is the single biggest lever they haven't pulled.

Part of The Body Blueprint — 41 chapters across every system that matters. £6 per chapter, or £29 for the full bundle (save £217).