When we sleep well, we wake up feeling refreshed and alert for our daily activities. Sleep affects how we look, feel and perform on a daily basis, and can have a major impact on our overall quality of life.
To get the most out of our sleep, both quantity and quality are important. Teens need at least 8 hours—and on average 9¼ hours—a night of uninterrupted sleep to leave their bodies and minds rejuvenated for the next day. If sleep is cut short, the body doesn’t have time to complete all of the phases needed for muscle repair, memory consolidation and release of hormones regulating growth and appetite. Then we wake up less prepared to concentrate, make decisions, or engage fully in school and social activities.
NREM (75% of night): As we begin to fall asleep, we enter NREM sleep, which is composed of stages 1-4
N1 (formerly “stage 1”)
N2 (formerly “stage 2”)
N3 (formerly “stages 3 and 4”)
REM (25% of night): First occurs about 90 minutes after falling asleep and recurs about every 90 minutes, getting longer later in the night
In addition, levels of the hormone cortisol dip at bed time and increase over the night to promote alertness in morning.
Sleep helps us thrive by contributing to a healthy immune system, and can also balance our appetites by helping to regulate levels of the hormones ghrelin and leptin, which play a role in our feelings of hunger and fullness. So when we’re sleep deprived, we may feel the need to eat more, which can lead to weight gain.
The one-third of our lives that we spend sleeping, far from being “unproductive,” plays a direct role in how full, energetic and successful the other two-thirds of our lives can be.