The science of sleep is far more theoretical than you may think. Theories remain unproven for why we evolved to sleep. In fact, part of the reason we humans skip out on needed shut-eye is because our bodies can adapt to less. We may not perform optimally or think clearly, but we can make it through. If we can pull an all-nighter why is this an essential part of life?
What is sleep?
Seriously – it’s more than just that time in which you black out and wake up to an alarm that always seems to go off 5 minutes earlier than you want it to.
Sleep is a natural, reoccurring, required state of altered consciousness for animals. Characterized by relatively inhibited sensory activity and inhibited voluntary muscle contractions.
In a state of sleep most animals are in a heightened anabolic state, meaning the body is experiencing growth and repair of the immune system, skeletal and muscular systems.
Why we need sleep?
We spend a third of our lives sleeping. Or at least that’s what’s supposed to happen. While we might often question if we really need that extra hour when trying to go to bed on time – we often wake up the next morning regretting our decision to stay up late.
A way to understand why we sleep is to compare it to another life-sustaining sensation – hunger. Hunger (or HANGRY pains) is an instinct to give the body nutrients. Our body’s internal clocks drive us to eat so we don’t feel hungry; in the same way our bodies are driven to our pillows at night because we are sleepy (I know tell that to your 2-year old still full of energy at 10pm).
But other than the body’s internal drive – why do we REALLY sleep? How did that evolutionary trait occur? Here are two theories from the division of Sleep Medicine at Harvard Medical School:
1: Inactivity Theory – suggests that inactivity at night is a survival adaptation that kept organisms our of harm’s way during a time of vulnerability. The theory is that animals that stayed quite and still during times of vulnerability had an advantage over animals that remained active. Being still and quite in the dark prevented them from encountering predators.
2: Energy Conservation Theory – suggests the primary use of sleep is to conserve energy and demand for resources (i.e. food). Energy metabolism is significantly reduced during sleep therefore overall caloric needs are decreased. Historically during times of limited resources this theory is much easier to understand – now that our food sources are plentiful this theory is only relevant to natural selection.
3: Restorative Theory: suggests that sleep “restores” what was lost in the body while we were active. The evidence to back this theory is that animals deprived of sleep lose all immune function and die in a matter of weeks. Certain functions of the body like muscle growth, tissue repair, protein synthesis, and growth hormone occur mostly (or in some cases only) during sleep.
4: Brain Plasticity Theory – suggests that sleep is connected to changes in the structure and organization of the brain. Basically means that sleep plays a critical role in brain development. Infants, whose brains are still developing, spend 13-14 hours of their day sleeping and about half of that time is spent in the deepest state of sleep, the REM cycle.
Benefits of Sleep
While science can’t prove why humans sleep researchers can prove the benefits to getting the required about of Zzz’s in your life.
Improve Memory – concept called consolidation occurs. Memory processes have been shown to be stabilized and enhanced (sped up and/or integrated) by nocturnal sleep and even daytime naps
Spark creativity – emotional components to memory are strengthened when can help spark creative processes
Improved athletic performance – increased reaction times, increased stamina, and less fatigue following training
Improve fat loss & Increased preservation of muscle mass – Researchers from the University of Chicago found that those who were dieting and rested well saw more 56% more fat lost than those sleep deprived. In fact, those sleep deprived individuals lost more muscle mass over the course of the study.
Safer Driver – National Highway Traffic Safety Administration reported in 2009 that being sleep deprived accounted for the highest number of fatal single-car, run-off-the-road crashes. This was an even higher stat than driving under the influence.
Decrease Anxiety and Depression A restful night of sleep can help you avoid being irritable and anxious.
Doctors warn you that you cannot make up for sleep by simply sleeping more on the weekends. If you find yourself sleeping through your weekend you are not getting enough sleep during the week. You must find that happy balance. Compare a lack of sleep to credit card dept Once you rack up enough sleepless nights your body’s interest rate will shut down until you pay it all off. It can take days to recover your interest rate in lost sleep. Often a two-day weekend is often not enough.
“There are lab studies that show that if you’re an eight-hour sleeper and you get six hours of sleep, that two-hour difference can impact your performance so that it equates to how you would perform if you had a 0.05 blood-alcohol level.”
Sleep like an Athlete
Top-level athletes train to sleep. Whether it’s an Olympic athlete or NFL quarterback part of their training regimen is getting adequate sleep. Here are some of the scientifically perfect conditions for sleep the pros use:
Regardless of whether you are a super star in your sport – we could also use a little more training in becoming champions of sleep. Listen to your body – and take the time for rest. In a digital age where most of us are guilty of screen-time before bed time try to turn-off and shut-down the hour prior to going to bed. Aim to get at least 7.5 hours of sleep per day, with a minimum of 6. Don’t let your sleep dept add up and find yourself with high interest rates with low performance and irritability.
And check out some ABOUT TIME sports nutrition supplements that aid is muscle recovery and adequate sleep: