Wellness & RecoveryNot all sleep hours are equal. Here's what's actually happening across a night of sleep, and why quality matters as much as duration.
Sleep moves through several stages, including light sleep, deep sleep, and REM sleep, cycling roughly every 90 minutes throughout the night โ each stage serves genuinely different restorative functions.
Deep sleep is when the majority of growth hormone release and physical tissue repair occurs, making it particularly important for anyone training regularly, beyond just feeling rested.
REM sleep is associated with memory consolidation and emotional processing โ getting insufficient REM sleep, even with adequate total hours, can affect mood and cognitive function the following day.
Waking during deep sleep tends to produce a groggier, harder start to the day compared to waking during lighter sleep stages โ this is part of why sleep quality, not just duration, meaningfully affects how rested someone feels.
Struggling to fall asleep often has less to do with the hour you go to bed and more to do with the hour before it.
