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Sleep debt × cortisol

Poor sleep raises cortisol. High cortisol fragments sleep. 6 questions to score the loop.

Question 1 of 6
Average hours of sleep on a weeknight?
Question 2 of 6
Do you "catch up" on sleep on weekends?
Question 3 of 6
How long does it take you to fall asleep?
Question 4 of 6
Do you wake during the night?
Question 5 of 6
Alcohol within 3 hours of bed?
Question 6 of 6
Screens within 30 min of sleep?

Frequently asked questions

How much does sleep deprivation raise cortisol? +
Studies show even one night of partial sleep restriction (4–5 hours) can raise next-day cortisol 30–50% in the afternoon. Chronic sleep restriction (5–6 hours/night) shifts the entire cortisol curve — higher evening cortisol, blunted morning peak. Both fragment subsequent sleep.
Why does alcohol disrupt sleep cortisol? +
Alcohol initially sedates but metabolizes within 3–4 hours. As blood alcohol drops, the body triggers a stress response — heart rate rises, cortisol spikes, REM rebound fragments sleep. This is why you wake at 3 AM after drinking and feel wrecked even after 8 hours in bed.
Can I "catch up" on sleep at weekends? +
Partially. Research shows weekend recovery sleep restores SOME cognitive performance but does NOT fully reverse metabolic and cortisol effects of weekday restriction. Consistent sleep timing is more important than total hours.
How does Cortisol+ use sleep data? +
Cortisol+ pulls sleep stage data from Apple Watch (REM, deep, core, awake time). REM and deep sleep deficits are the strongest predictors of next-morning cortisol elevation. The app surfaces this correlation so you can see exactly which sleep nights spike your cortisol the next day.