“Sleep quality and duration should be considered a vital sign, as they are strong indicators of overall health and quality of life,” said Kristen Knutson PhD, a National Sleep Foundation Sleep in America™ Poll Scholar.
If you’ve ever seen a therapist at Made 2 Move, you know that sleep quality is one of the first things we ask you about. Everyone knows that they should probably be getting more sleep because we feel best when we are rested, but have you ever thought about the biological purpose that sleep serves? Outlined below are a few of the reasons our bodies need sleep, that will hopefully encourage you to get more Zzz’s.
The body is a machine and all machines require maintenance. A car cannot run indefinitely without running the risk of overheating, breaking down, or at the very least, shortening the lifespan of the car. Similarly, humans cannot function optimally without “maintenance” in the form of sleep (~7-9 hours per night).
Throughout the day, the body expends energy. At night, instead of using energy for your studies, workout class, or Made 2 Move PT session, that energy is used to help rebuild the body. Sleep helps our bodies utilize the food we consume throughout the day to replenish glycogen stores in the muscle and liver. Sleep also gives our brains time to reset. During waking hours, our brains may use up to 25% of the body’s energy, so restful sleep gives the brain “time off” to conserve energy for activities of the following day.
Restoration and Hormones
Throughout the day, our body uses energy to drive brain activity, exercise, and metabolic processes. At night, our body uses this energy to repair, rebuild, and restore. The body has to replenish materials that were used up during waking hours, such as proteins. Exercise causes micro-tears in our muscles that need to be repaired in order to build muscle mass. This is especially important for athletes because they break down additional proteins that have to be replenished in order to actually build muscle. Thus, if you are depriving yourself of sleep, you’re essentially depriving yourself of the “gains” you work so hard for in the gym.
The restorative nature of sleep is especially important for our youth and adolescent Made 2 Move athletes, as growth hormone is released during sleep. Growth hormone is one of the key players in muscle hypertrophy, even in adults. For adolescent and youth athletes, growth hormone plays an even greater role in growth beyond the point of muscle hypertrophy. While their muscles have to rebuild following breakdown from their sport or resistance training, youth and teens are also still growing in height, weight, brain, and bone density.
Lack of sleep interferes with growth hormone release which can stunt growth in adolescents. Lack of growth hormone release can also contribute to injury, in both adolescents and active adults. Injuries could be due to insufficient growth hormone release, and thus inadequate bone growth or muscle repair. Injury could also be due to decreased reaction times, another side effect of sleep deprivation because the brain did not recover as much as it needed to.
Another hormone affected by sleep deprivation is cortisol. While decreased sleep leads to decreased growth hormone, it leads to elevated cortisol levels. Cortisol is commonly referred to as the “stress hormone.” Cortisol levels fluctuate on a 24 hour cycle, just as our circadian rhythms do. If our sleep is out of whack, our cortisol levels will also be out of whack and vice versa. While cortisol is necessary in some regards, excess cortisol can have a catabolic (breakdown) effect. This means that it is breaking down instead of building up, not a desirable effect in terms of strength training or rehabilitation in which the goal is to build muscle.
Sleeping between bouts of learning and recall has been shown to improve retention of learned information. This is important not only for students, but for any human being. Don’t we all strive to learn something new every day? What about remembering how to do the exercises prescribed at your Made 2 Move P.T. session three days ago?
Sleep affects our learning of complicated motor skills and declarative memory tasks. Complicated motor skills include learning technical lifts like the snatch and clean and jerk. While we know sleep is important for rebuilding the muscles that were broken down during that lift, sleep is also vital for our body to forge the neural pathway of how to do that lift or skill. Declarative memory tasks involve recalling facts or statements. Isn’t it frustrating when you can’t recall what someone told you just yesterday or can’t remember the name of a person you’ve met two times?
Sleep and Appetite
Nutrition is another key aspect of health that our Made 2 Move PTs will inquire about in your initial evaluation. Did you know that your appetite is affected by your sleep? Appetite may be altered following nights when you do not get adequate sleep. Two hormones: ghrelin (appetite stimulant, aka “I’m hungry”) and leptin (appetite suppressant, aka “I’m full”) are involved in hunger regulation and are affected by sleep deprivation. Lack of quality sleep can cause an increase in ghrelin and a decrease in leptin. This hormonal shift will likely lead to a blunting of fullness and a heightening of hunger.
In addition to elevated ghrelin levels, a blood lipid called endocannabinoid also increases when you do not sleep enough. Endocannabinoid acts on the brain in a way that causes you to crave fatty, sugary foods, especially in the evenings.
While sleep deprivation causes altered hunger cues due to hormonal fluctuations, there is also the simple fact that the less hours you spend in bed, the more hours of the day you will probably spend in front of the fridge or pantry. The more time you’re awake, the more time you will most likely spend eating.
Get your Zzz’s
At Made 2 Move, we often refer to the “toolbox” we have for rehabilitation and optimization of daily living. Sleep is one of the most vital tools in our toolbox, and should be capitalized upon because of its role in memory, energy and appetite levels, and muscle building.
Instead of beating yourself up for not getting enough sleep, try to view sleep as an exciting tool that can help you reach your goals. Now turn off your phone and take a 20 minute power nap or get those 7-9 hours of shut-eye! Interested in physical therapy at Made 2 Move? Reach out to firstname.lastname@example.org today to set up your initial evaluation.