Sleep & Circadian
How your circadian clock governs recovery, the levers that actually move sleep quality, and why most biohacks fail when sleep is broken.
About this classroom
Sleep is the foundation the rest of health optimisation sits on - and the one people most often try to shortcut. This classroom covers how the circadian clock governs recovery, which levers genuinely improve sleep quality, and why interventions elsewhere tend to fall flat when sleep is broken.
Where the evidence stands: The fundamentals here are unusually well established - light exposure, timing and consistency have strong support. Many gadget-based sleep claims are far weaker.
What you will learn
- How the circadian clock works - Light, timing and the internal rhythm that sets everything from alertness to hormone release.
- The levers that actually work - The sleep habits with the strongest evidence - and the popular ones that do not hold up.
- Light, temperature and timing - The environmental inputs that shift the clock, and how to use them deliberately.
- When to seek help - Signs that a sleep problem is clinical rather than a habit to tweak.
Curriculum
The basics
How the internal clock governs everything from alertness to recovery.
What actually works
The sleep levers with the strongest evidence - and the popular ones that do not hold up.
Troubleshooting
What to tweak yourself, and when a sleep problem is clinical.
Sleep conditions
Separate habits from conditions that need proper assessment and treatment.
Schedules & timing
Sleep duration, shift work, travel and correctly timed interventions.
Frequently asked
- How much sleep do I actually need?
- Most adults land in a well-studied range, but need varies. The classroom focuses on quality and timing rather than a single magic number.
- Do sleep trackers work?
- They are better at trends than at precise stages. Useful for spotting patterns, not for diagnosing yourself.
- Is it too late to fix my sleep?
- Rarely. Circadian and behavioural levers can shift sleep at almost any age - though persistent problems deserve professional input.
Sources for this classroom
Educational content only. Not medical advice, diagnosis or treatment. Always consult a qualified healthcare professional before changing your health regimen.