Recent News and Events

Alison McGinnis, PT, DPT, FAFS

Posted in Blog.

April 21st, 2020

The Importance of Sleep

Sleep is the most important lifestyle factor influencing your overall health and well-being, both in the short term and the long term. Most of us know we are supposed to get 7-9 hours of sleep each night, but for many, sleep is the first thing we give up when our lives get busy. Some of us even pride ourselves in our ability to burn the candle at both ends and brag about how little sleep we need to stay “productive”. Unfortunately, you can’t lie to your body and it knows when it’s not getting sufficient sleep.


A full night of sleep is the best performance-enhancing “drug” you can take advantage of legally. When you sleep less than 6 hours a night your aerobic output drops and your time to exhaustion drops 10-30%. Vertical height and limb extension power tests are reduced, and peak and sustained muscle strength tests decrease significantly. It has also been shown that the amount of air the lungs can expire when sleep deprived is reduced as well, leading to increased lactic acid buildup with reduced blood oxygen saturation and increased carbon dioxide levels. Then there’s the injury risk. Sleeping only 5-6 hours a night increases your risk of injury 200% across a season.


There are also the non-performance effects. Sleep deficiency impacts hormone levels of Leptin (satiety hormone) and Ghrelin (hunger hormone) in the body. Poor sleep suppresses leptin and makes you not feel satisfied after eating, and ghrelin increases by 15% after just one bad night of sleep causing you to feel hungrier and crave simple carbohydrates the next day. And our willpower to resist temptation is drastically reduced without sleep as well. A study out of UC Berkeley showed increased activity in the amygdala and decreased activity in the insular cortex and frontal lobe (responsible for willpower) when sleep deprived, resulting in this loss of control. This combination is linked to weight gain in both adults and children, and makes it difficult to sustain weight management when in a sleep deprived state.


Lack of sleep also affects our memory and brain health, and is thought to be a leading cause of Alzheimer’s disease. When we sleep, the glymphatic system is active and responsible for removing toxins that have accumulated in the brain throughout the day. Our brain cells actually shrink by 50% during sleep to allow the glial cells of this system to work efficiently. When the body doesn’t have enough time in sleep to remove all the buildup, waste products like beta amyloids are left behind and can accumulate. This may lead to amyloid plaque formation in the brain which causes Alzheimer’s disease. With each passing night of insufficient sleep, this waste removal system leaves behind unwanted sewage, compounding long term.


Routinely sleeping less than six hours a night also compromises your immune system and its ability to fight off infection, as well as significantly increasing your risk of cancer long term. Inadequate nightly sleep for even just one week can disrupt glucose (blood sugar) levels so much that you would be measured as pre-diabetic. Lack of sleep also increases the likelihood of your coronary arteries becoming stiff and brittle, leading to cardiovascular disease, congestive heart failure, and stroke.


Even the change of one hour of sleep has profound effects. With daylight savings time, in the spring when we lose an hour of sleep there is a 24% increase in heart attacks the next day. In the fall, when we gain an hour, there is a 21% reduction in heart attacks. Sleep matters.


Poor sleep has also been associated with all major psychiatric conditions including anxiety and depression.


Now I understand that a shift in our cultural, societal, and professional values needs to happen before we can fully appreciate sleep and make it a priority globally. But individually we have the power to change our habits and prioritize the one thing that can have a positive effect on all our body systems. There is no app or gadget that can replace good, quality sleep. The best thing you can do is try and get more of it every night.


Here are a few tips to try and help you sleep better:


  1. Set a Screen Curfew every night. Blue light emitted from devices lowers melatonin levels by up to 50%. Melatonin is a hormone produced by the pineal gland that controls your sleep-wake cycles. Not having enough of this hormone can cause your brain to stay awake. Also, endless scrolling on apps or watching TV activates your dopamine reward centers in the brain which keeps you coming back for more, even against your better judgement, and keeps you awake longer. Setting a time each night to turn off electronics will allow your body to unwind and prepare to fall asleep.
  2. Cycle caffeine, and Avoid after 12pm. It takes 72 hours to completely detoxify your body from caffeine, so that you can reach the same level of “buzz” the next time. When you drink caffeinated drinks regularly, you reduce its effectiveness which requires more caffeine to reach the same “buzz” the next time. If you can’t cycle your coffee habit, at least try to cut yourself off by 12pm. Caffeine worsens your sleep quality and takes a long time to wear off, even if you are no longer feeling the effects of your last cup, so the sooner you stop drinking it the better your sleep quality will be.
  3. Work out in the Morning. Natural cortisol levels in your body should peak around 6am and drop to their lowest levels by 10pm. When you exercise, your body produces more cortisol as a result. By working out in the morning you help to mimic this natural cortisol curve, and prevent spikes in cortisol later in the day that can lead to chronic sleep deprivation.
  4. Get Sunlight. Exposing yourself to sunlight between 6-8am helps to stimulate cortisol levels in the morning. Without this stimulation in the morning our internal clock struggles to know what to do. (Also key for fighting jetlag)
  5. Heal your Gut. There is 400x the melatonin in our gut than in the brain. Eating a diet rich in pre- and probiotic foods, and getting enough fiber are key to a well-functioning gut.
  6. Get into a Routine. Your body is better at falling asleep and staying asleep if it does it at the same time every night. Try to pick a bedtime and a wake time, and stick with it (even on weekends). The more consistent you are, the better quality of sleep you’ll get.


Utilize this time to try and make small changes. Start to implement better sleep habits and make sleep a priority in your life. It has a profound impact on both short and long term health. Whether you want to perform better at work, decrease chronic pain, or improve your performance, quality sleep is key.

Thank you! Your subscription has been confirmed. You'll hear from us soon.
Subscribe to our newsletter: