Why Sleep When You Can Drink Coffee? (Part 2)
By Craig Jensen
Sleep is one of the biggest mysteries ... why do we need it? Although we still can't really answer that question properly, scientists have made strides in understanding what it does, how it works, and what happens to our bodies and brains when we aren't getting enough of it. My last post discussed coffee/caffeine and how it affects our brain. Following this blog post, I will look at how coffee and caffeine overlap with sleep, and whether caffeine can actually help to replace sleep.
Before looking at that relationship, however, let's look at how sleep works so that we know what we are dealing with. Here's some of what we know: (a snoozer for you if you don't like facts) Sleep is comprised of two different stages: NREM (non-rapid eye movement) and REM (rapid eye movement). A majority of our time sleeping is spent in NREM (roughly 75-80 percent) which has four stages of its own where we move progressively deeper into sleep. After these four stages, we move into REM (the other 20-25 %), where we get some of our deepest and most restorative sleep.
NREM begins with a very light stage 1 sleep where we drift in and out of being awake and asleep for about 10-20 minutes. After this, we enter stage 2, which is deeper and more stable. We spend about 50 percent of our total time asleep in this stage. Once we move tostage 3 and 4, we enter SWS (slow-wave sleep), or "deep sleep." Our blood pressure and body temperature drop, as does our breathing rate. Our muscle tissue and energy begin to be restored, partially because of the release of different hormones. During these stages we have little-to-no eye movement or muscle activity.
Our brain also begins to consolidate memories, which is an essential function for not only remembering and recalling information later on, but also for making room for new memories to be stored. After the 4 stages of NREM sleep, we finally enter into REM sleep. Here, true to its name, our eyes move rapidly as we dream vividly. Our breathing becomes quick and irregular and our muscles often become paralyzed, although our heart rate and blood pressure rise. REM sleep, along with stage 3 and 4 of NREM, is essential because of its physical, mental, and emotionally restorative powers. Even though we don't know why we need sleep, it is clear that it is incredibly important.
Sleep's restorative functions facilitate much of our mental and physical health, including our ability to learn efficiently. But, the real question is, is sleep essential for learning? We already know that coffee allows our brain to fire more neurons when it is consumed because the caffeine blocks the chemical adenosine responsible for slowing down nerve activity. Firing more neurons allows for higher brain activity/efficiency and more capacity for performing tasks. Isn't that enough to facilitate learning? Sorry for the teaser but... Stay tuned for part 3.
Craig Jensen is the President and CEO of LearnNowOnline. Craig has led the company’s change from instructor-led classroom training, to self-study CD/DVD training, to the award winning online learning solutions offered today. Craig is passionate about helping individuals and businesses of all sizes solve their problems through practical learning and technology. He is involved in setting direction for the company, including selecting training content for development with resources to support all learning styles. He is also involved in The CEO Roundtable organization in the Twin Cities as well as the Minnesota High Tech organization. In his spare time, Craig loves to travel, golf, and partake in water sports of all kinds.