Humans sleep in 90-minute cycles so if you wake up in the middle of one of those cycles you're going to find it harder to wake up. Photo / Getty Images
Waking up feeling well-rested can be so hit and miss for many of us.
Even if you’re getting enough hours of sleep sometimes we still feel exhausted and have no idea why.
Millions of people have tried different hacks such as having a bath before bed or a hot drink, or switching off your screen time 30 minutes before bed.
But a sleeping expert has revealed there is one simple reason many are spending their entire day yawning and feeling tired despite sleeping enough hours.
Expert Addison Jarman has shared the simple science behind our sleeping patterns.
Taking to social media, she explained we sleep in 90-minute cycles and if you wake up at the wrong point of the cycle then you're going to find yourself more tired.
Even if you have a full night's sleep, waking up at the wrong time will leave you drowsy.
Our sleep cycle made up of 65 minutes of normal, non-REM (rapid eye movement) sleep, 20 minutes of REM sleep and a final 5 minutes of non-REM sleep.