New research identifies four key factors that make a difference to waking up well in the morning – going to midday alert and cooling off at one end of the scale, or combating drowsiness and multiple snooze button presses to the other.
The team behind the study say these factors, independent of the genetics an individual is born with, can all be tweaked to some degree to ensure a better start in the morning.
“Why do we humans fluctuate in our alertness from day to day?” asked the team of researchers led by neuroscientist and sleep researcher Raphael Vallat of the University of California (UC) Berkeley in their published paper.
“Why do you wake up one morning feeling alert, while another morning floundering in this level of wakefulness?”
A total of 833 people took part in the study, most of whom were twins (this helped the researchers filter out variations due to genetics). For two weeks, food intake, physical activity, sleep patterns and glucose levels were recorded, while the volunteers also rated their alertness at various times of the day.
The first factor that matters is the sleep profile: the duration, timing and efficiency of sleep during the night. Sleeping longer and waking up later than normal were both associated with better morning alertness.
The second factor was the amount of exercise people had done the night before. Higher levels of movement during the day (as well as less physical activity the night) were associated with more continuous and less disrupted sleep, which in turn predicts increased alertness of participants in the morning.
Third, there was breakfast. Morning meals with more carbs led to better levels of alertness, while more protein had the opposite effect. By keeping the same calories in the meals provided, the researchers were able to focus on the nutritional content of what was being eaten.
Finally, an increase in blood sugar after breakfast – tested using a pure glucose liquid drink – was associated with a decrease in alertness. A lower glycemic response, seen after participants ate a high-carb breakfast, improved alertness.
In other words, how the body processes food matters, and too much sugar leads to a sugar crash rather than a morning sugar rush.
Other factors at play regarding daily alertness included the mood and age of the volunteers, although these were not as manageable as what time you go to bed and what you have for breakfast. .
“Our results reveal a set of key factors associated with alertness that are, for the most part, not fixed. Instead, the majority of factors associated with alertness are modifiable, and therefore permissive to behavioral intervention,” write Vallat and his colleagues.
The team is keen to investigate some of the mechanisms behind these associations in order to gather more precise data; participants reported their level of alertness, which was not measured using any scientific instrument.
That said, in addition to reporting their daily behaviors, participants ate standardized meals and wore an accelerometer wristwatch (to measure sleep and activity) and a continuous glucometer (to measure post-meal blood sugar). which is better than most studies that rely on questionnaires alone.
Another challenge for future studies will be to determine how and why sleeping longer and sleeping later, compared to that person’s typical norm, boosts morning alertness – at least in this study. We know from other research that excessive sleep can also impact well-being.
Improving sleep quality affects many other areas of our lives, including the safety of those who work in jobs where mistakes can be fatal, including firefighters, nurses, and airplane pilots.
“This question is scientifically elementary but also of societal importance given that the inability to maintain alertness throughout the day is a major causal factor in road traffic and occupational accidents, responsible for thousands of deaths each year. “, write the researchers.
“Additionally, insufficient sleep resulting in impaired daytime alertness is believed to be responsible for significant loss of work-related productivity, higher healthcare utilization, and work absenteeism.”
The research has been published in Nature Communication.