A new study identifies key factors that make you wake up in a good mood in the morning. The team behind the study states that these factors, regardless of the genetic traits one is born with, can be somewhat modified to ensure a better start in the morning. The research team, led by neuroscientist and sleep researcher Rafael Valle, from the University of California, Berkeley, posed the question in their published paper: "Why do we humans fluctuate in our wakefulness from day to day? Why do we wake up some mornings feeling alert, while on other mornings we struggle to wake up?"
A total of 833 participants took part in the study, most of whom were twins (this helped researchers filter out differences due to genetics). Over the course of two weeks, meal times, physical activity, sleep patterns, and glucose levels were recorded, while volunteers also rated their alertness at several points each day.
The first important factor was sleep pattern: the duration, timing, and efficiency of overnight sleep. Longer sleep duration and waking up later than usual were associated with improved morning alertness. The second factor was the amount of exercise participants had on the previous day. Higher levels of daytime activity (along with less physical activity at night) were linked to more sustained and less disturbed sleep, which, in turn, predicted increased alertness for participants in the morning.
Thirdly, breakfast played a role. Meals in the morning that contained more carbohydrates led to better alertness levels, while more protein had the opposite effect. By keeping calorie intake in the meals constant, researchers could focus on the nutritional content of what was consumed. Finally, higher blood sugar levels after breakfast — tested using a pure glucose liquid drink — were associated with decreased alertness. A decrease in blood glucose levels, observed after participants consumed a carbohydrate-rich breakfast, led to improved alertness. In other words, how the body processes food is important, and excessive sugar intake results in a sugar crash rather than a morning sugar rush.
Among other factors that play a role in daily alertness are the mood and age of the volunteers, although these factors are not as controllable as when you go to bed and what you consume during breakfast. Valle and his colleagues wrote: "Our results reveal a set of key factors related to alertness that are largely modifiable."
The team aims to investigate some of the underlying mechanisms behind these associations to gather more accurate data. Participants reported their levels of alertness, which were not measured using any scientific tools. However, in addition to reporting their daily behaviors, participants consumed standardized meals and wore a wristwatch with an accelerometer (to measure sleep and activity) and a continuous glucose monitor (to measure blood sugar levels after meals), which is superior to most studies relying solely on questionnaires.
Another challenge for future studies is to determine how and why longer sleep and waking later, compared to a person's typical baseline, enhance morning alertness — at least in this study. We know from other research that oversleeping can also affect well-being. Improvements in sleep quality impact many other areas of our lives, not least the safety of those in jobs where mistakes can be fatal, including firefighters, nurses, and pilots.
