Daylight saving time has officially began! This means different things for different people. For some of us, it’s a little bit darker when we start our commute into work or roll out of bed for our morning coffee. Many look forward to this time of year as we’ll now have daylight after 5:30 pm for at least the next 7 months and warmer weather is certainly on the horizon. However, what it likely means for all of us is an hour of sleep lost. An hour, that undoubtedly, would be nice to have heading into Monday.
The Center for Disease Control and Prevention (CDC) estimates approximately one-third of Americans are sleep deprived, with those numbers slightly higher in Midwest and southern states like Kentucky and Indiana.[i] Every year when we spring forward, an enormous science project takes place, in which we are all subjects. In the day(s) that follow this unavoidable loss of sleep, there are increased incidents of motor vehicle accidents and hospitals report yearly spikes in visits due to heart-attacks across the U.S.
Pause. I know what you’re thinking: I’m a physical therapist, why am I writing about losing an hour of sleep last night? Is this a political blog post? (Definitely no, but it is worth noting that legislature is the state of Kentucky is considering a permanent shift to “daylight saving” time.) Does the hour of sleep I lost last night really matter? And the answer is yes, it really does. Not only should sleep matter to me as a health care provider, but it should matter to you as well.
Continually obtaining less than the optimal 8 hours of sleep per night has been tied to increased risk of heart and kidney disease, high blood pressure, diabetes, obesity, stroke, dementia, and Alzheimer’s.[ii] Non-optimal sleep lowers our ability to fight common infection and inflammation and our body’s ability to produce testosterone and growth hormones. The decrease in cognition and responsiveness seen with lack of sleep, is likely the reason we see a bump in accidents each year after pushing our clocks forward. And this message wasn’t just written for the night owls logging 4-5 hours of sleep per night. More recent research has demonstrated that accumulative sleep debt created by consistently missing just small amounts of sleep has the same negative consequences for our health.
As physical therapist, we care about our patient’s rest for a multitude of reasons. At the top of that list is the close relationship between sleep and our body’s ability to process and respond to pain. Studies have shown that poor sleep has a strong influence on pain levels experienced the following day and can become a predisposing factor to developing chronic pain.[iii] This matches what neuroanatomy (the study of the brain and the nervous system) tells us about how our brain functions. With less than optimal sleep, the portions of our brain that help us make decisions and problem solve (frontal lobe) have decreased activity. Meanwhile, the portion of our brain that interprets painful stimulus (somatosensory cortex) and process fear and emotion (amygdala) go into overdrive. Not only does missing sleep deprive our body’s ability to repair itself, it can make our symptoms from our injury much more difficult to manage.
Another reason as therapist we care so much about sleep is it directly impacts our body’s ability to learn and perform new, functional movement patterns. Sleep has long been known to be a key component of learning and cognitive function. Sleep is imperative for our brains to process and move information to “long term storage” where, much like riding a bike, once you know, you know for good. Whether you are learning a new computer program at work or a new exercise and trying to return to running without compensating for that pesky hip pain… sleep is key in making our actions automated and effortless. In fact, significant correlation has been found between movement improvements and stage II n-REM (non-rapid eye movement) sleep that occurs between the 6 and 8 hour mark of rest.[iv] Moral of the story: Prioritizing other activities over that last hour of needed sleep, could play a major role in our ability to improve the way we move and perform.
Not only can a good night’s rest help us to feel and move better, it can actually reduce our chance of sustaining an injury. Recent research has found that risk of injury increases with each hour short of 8 we sleep each night. When personal and occupational characteristics were controlled for, the same study found that those sleeping less than 5 hours a night were 1.5 times as likely to sustain an injury.[v] Similar research has been performed on young athletes, and for teenagers specifically, risk of injury nearly doubles when sleeping less than 8 hours a night.[vi]
While we have no control over the hour of sleep lost due to daylight saving, we can influence the quantity and the quality of sleep we’re getting. Just as we make decisions regarding food intake or exercise, sleep is an important lifestyle factor that is often overlooked in overall health. In my next blog post I’ll share some pointers on obtaining the best night of sleep possible and how to improve sleep quality for those nights, like during daylight saving time, when clocking 8 hours is much more difficult.
[i] [i] “CDC – Sleep and Sleep Disorders – State Fact Sheets.” Centers for Disease Control and Prevention, Centers for Disease Control and Prevention, 4 May 2017, www.cdc.gov/sleep/publications/factsheets.html.
[ii] Buysse, Daniel J. “Sleep Health: Can We Define It? Does It Matter?” Sleep, Associated Professional Sleep Societies, LLC, 1 Jan. 2014, www.ncbi.nlm.nih.gov/pmc/articles/PMC3902880/.
[iii] Afolalu, Esther F., et al. “Effects of Sleep Changes on Pain-Related Health Outcomes in the General Population: A Systematic Review of Longitudinal Studies with Exploratory Meta-Analysis.” Sleep Medicine Reviews, W.B. Saunders, 18 Aug. 2017, www.sciencedirect.com/science/article/pii/S1087079217300886.
[iv] Walker, Matthew P., and Robert Stickgold. “Its Practice, with Sleep, That Makes Perfect: Implications of Sleep-Dependent Learning and Plasticity for Skill Performance.” Clinics in Sports Medicine, vol. 24, no. 2, 2005, pp. 301–317., doi:10.1016/j.csm.2004.11.002.
[v] Grier, Tyson, et al. “Sleep Duration and Musculoskeletal Injury Incidence in Physically Active Men and Women: A Study of U.S. Army Special Operation Forces Soldiers.” Sleep Health, 2020, doi:10.1016/j.sleh.2020.01.004.
[vi] Milewski, Matthew D., et al. “Chronic Lack of Sleep Is Associated With Increased Sports Injuries in Adolescent Athletes.” Journal of Pediatric Orthopaedics, vol. 34, no. 2, 2014, pp. 129–133., doi:10.1097/bpo.0000000000000151.