Overview
- The suprachiasmatic nucleus in the brain coordinates circadian rhythms that regulate sleep, body temperature, hunger, and digestion to keep daily time.
- The cortisol awakening response, alongside falling melatonin and a rise in body temperature, prepares alertness minutes before an alarm in well-entrained sleepers.
- Consistent wake times and exposure to morning light train the master clock to anticipate your routine so wakefulness starts before the set time.
- Waking early yet feeling groggy suggests poor sleep quality or irregular timing, with alarms more likely to trigger sleep inertia when they interrupt deep sleep.
- Experts advise a stable 7–8 hour sleep window, morning sunlight, a dark and screen-free pre-bed environment, limited caffeine, alcohol, and heavy meals, and stress management to reduce premature awakenings.