Waking up groggy isn't just about how long you slept; it's about when you woke up. The National Sleep Foundation confirms that human sleep occurs in 90-minute cycles. If your alarm goes off in the middle of a deep sleep cycle, you experience "sleep inertia," leading to a massive spike in Cortisol (the stress hormone) which severely halts fat loss and increases cravings.
(We've already factored in 15 minutes to fall asleep)
The Hormone-Weight Connection
A study published in the Annals of Internal Medicine found that individuals who slept 5.5 hours per night lost 55% less body fat and 60% more muscle mass than those who slept 8.5 hours, despite eating the exact same calories.
Poor sleep lowers Testosterone and Growth Hormone (essential for muscle) while increasing Ghrelin (the hunger hormone) by up to 30%.
Optimize your macros & recovery
Sleep is free. So is our app. Use DietLog to track your protein, calories, and water intake completely free.
Get the Free App