The average American lives to be 74 and will spend almost 24 of those years sleeping. Twenty four years is certainly a long time to spend sleeping, but how many of you take part in the daily ritual of a morning cup of coffee to kick-start the day? Six to eight hours of sleep a night should be enough to propel a person through the following day, right? Well, early on in college I felt that this simply was not true.
At first I thought that the demands of academics and a part-time job were responsible for zapping my energy and forcing me to down several cups of coffee a day. Caffeine became a staple of my diet in the afternoons and evenings when I burrowed down into my books.
For a number of months I continually relied on caffeine to combat my tiredness and help complete assignments. During that time I began to exercise because I had repeatedly been told that it was a good tool for relieving stress, something that I feared was a contributing factor to my being so low on energy. I worked on an exercise schedule and two months later I was consistently running 5-6 days a week for thirty minutes. I was astonished how good exercise could make me feel and I also unintentionally cut down on my caffeine usage. I didn’t rely on caffeine to power me throughout the day and I was astonished by the effect that exercise had on my body.
The link between physical activity and getting quality rest was emphasized in a recent epidemiological study that examined data from the National Health and Nutrition Examination Survey (NHANES). It is estimated that approximately 35-40% of U.S. adults have problems with falling asleep at bedtime or have daytime sleepiness. Yes, we should be skeptical of statistics but if the actual number of Americans that have sleep problems is anywhere near that number, there is great reason to be alarmed. Why? Because poor sleep is associated with some very negative health outcomes in adults such as depression, cardiovascular disease, and type-II diabetes.
Researchers studied the association between objectively-measured physical activity and self-report questionnaires from a nationally representative sample of adults from all age groups. Researchers found that the people who took part in at least 150 minutes of moderate intensity physical activity per week were less likely to feel: sleepy during the day, have cramps while sleeping, and have difficulty concentrating if they were tired when compared to those who did not take part in physical activity.
Data from NHANES demonstrates that physical activity is very much associated with better sleep in the general population. But how and why is this, exactly? There are a multitude of reasons that I will not discuss about how exercise makes your body function better, sleep better, etc. Sorry but I want to talk about the brain! We’ve all heard the term “a healthy body leads to a healthy mind,” but have you ever wondered why that might be, exactly? Scientists have shown that exercise boosts brain power through the process of neurogenesis. Neurogenesis is the process by which new brain cells, or neurons, are formed. It is not surprising therefore that the area of the brain that is most affected by exercise is the hippocampus, which of course is extremely important for memory and learning.
Exercise is also important because it increases the flow of oxygenated blood to the brain. This is extremely important because the brain of a healthy body is estimated to use more than 20% of oxygenated blood that is made available to all tissues. The brain needs oxygen in order to metabolize nutrients so that it may function properly and this of course leads to a brain that is alert and fully functional.
One more thing worth mentioning briefly is the effect that exercise might have on deep or “REM” sleep. I recall coming across a study that proved exercise to be beneficial for people suffering insomnia because it allowed them to exhaust their body to a point that made it easy to fall into a deep slumber, or at least that was the main point without all of the scientific jargon. During the different stages of sleep, the neurons of the brain are active in varying degrees and this activity leads to bad sleep or good and refreshing sleep. The neuroscience of sleep however is another extremely large topic that will probably be addressed on here sooner than later…
I can attest to the strong correlation between physical exercise and optimal brain functioning because I experienced it first hand as a freshman in college. I hope that more people learn to rely less on caffeine and more on exercise in order to increase their cognitive capacities. Don’t get me wrong though, I am no saint because I do still enjoy a good cup of coffee. Although it is widely consumed by people all over the world, most are oblivious to the actual mechanism that allows caffeine to increase our energy. This perhaps is a good topic for a later discussion…