How Your Body Resets and Recovers During Sleep
Have you ever had a tough decision to make and someone told you to sleep on it?
Well, they may have been onto something.
We all know what we feel like when we don’t get enough sleep. Our work performance is poor, our physical health struggles, we’re more likely catch a cold, and we become overwhelmed at just about anything (including what to have for dinner). There’s a reason we need to spend a third of our lives asleep.
Why do we need sleep?
Sleep gives our brains and bodies the chance to recover and rebalance every day.
When we’re awake, our nerve impulses and neural connections work hard to keep up with our daily demands.1 During the day the synapses in our brain – the junction between nerve cells – are under constant stimulation, which is essential for our memory and learning.3 Sleep allows our neural networks to slow down and go back to a baseline, so our brains don’t get overloaded.3 This processes, known as potentiation, stop our minds from getting overwhelmed and enables us to wake feeling refreshed and ready for the day ahead.3 Microscopic image of our synapses have shown to expand during daytime stimulation and shrink with sleep, resetting the brain for the next day.3
Memory, Learning and Sleep
Improvements in learning are associated with a good night’s sleep, with quality long-term sleep enhancing our memories exponentially.3 Good-quality sleep increases the function of our cognitive load during our previous time awake and allows us to store memories and learnings.3
Sleep and Mood
Research suggests that sleep and our emotions interact, with nearly all neurological disorders expressing that disruptions to sleep affect our mood.2 Data indicates that when we’re sleep-deprived, our brains have an amplified response to negative emotional stimuli, as sleep helps us govern appropriate behavioural responses.2 A good night’s sleep is critical for maintaining the functional integrity of the brain, and, possibly, the functional integrity of your relationships.
Sleep can have a profound impact on our metabolism and hunger cues. One minute you’re tired, and the next you’re standing in front of the fridge with sweat furrowed between your brows, stuffing down the last piece of banana bread. Sleep assists in the regulation of our appetite hormones, leptin and ghrelin. Sleep helps suppress ghrelin (the hormone that keeps us eating) and stimulate leptin (the hormone that signals that we’re full).4
Sleep deprivation can impair a range of functions, including the regulation of our metabolism, cognition and immune system.2 Prolonged time spent awake weaken the strength of our synapses and overload our neural networks, inhibiting our ability to perform at our best and take on challenges throughout the day.3
The next time someone tells you to sleep on a decision, I’d listen with both ears!
1 De Vivo, L. Bellesi, M., Marshall, W., Bushong, EA., Ellisman, MH., Tononi, G., Cirelli, C. (2017). Ultrastructural evidence for synaptic scaling across the sleep/wake cycle [online]: Science.
2Yoo, S., Gujar, N., Hu, P., Jolesz, F., Walker, M. (2007). The human emotional brain without sleep – a prefrontal amygdala disconnect [online]: Current Biology.
3Griffith, L., Robash, M. (2008). Sleep: hitting the reset button [online]: Nature Neuroscience
4 Sharma, S., Kavuru, M. (2010). Sleep and Metabolism: An Overview [online]: International Journal of Endocrinology