A new study identifies four key factors that make the difference to waking up well in the morning – fueling up by noon and being refreshed on one end of the scale, or fighting off worry and multiple snooze button presses on the other.
The team behind the study say that these factors, regardless of the genetics a person was born with, can all be modified to some extent to ensure we get off to a better start in the mornings.
“Why do we humans fluctuate in our alertness from one day to the next?” 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 we wake up one morning feeling alert, and another morning falling to that level of alertness upon waking?”
The study involved a total of 833 people, most of whom were twins (this helped the researchers filter out variations due to genetics). Over two weeks, food intake, physical activity, sleep patterns and glucose levels were recorded, while the volunteers also rated their alertness at several points throughout the day.
The first factor that matters is the sleep profile: the length, time and efficiency of sleep during the night. Getting more sleep and waking up later than normal were both associated with better morning alertness.
The second factor was the amount of exercise people did the previous day. Higher levels of movement during the day (as well as less physical activity the night) it was is associated with more continuous and less disturbed sleep, which in turn predicted increased alertness from participants in the morning.
Third, there was breakfast. Morning meals with more carbohydrates led to better levels of alertness, while more protein had the opposite effect. By keeping the calories in the meals provided the same, the researchers could focus on the nutritional content of what was being eaten.
Finally, a rise in blood sugar levels after breakfast – tested using a pure glucose liquid drink – was associated with reduced alertness. A lower blood glucose response, seen after participants ate a high-carbohydrate breakfast, improved alertness.
In other words, how the body processes food is important, and too much sugar leads to a sugar crash rather than a morning sugar rush.
Other factors at play in daily alertness included the volunteers’ mood and age, although these are not as readily available 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. Rather, the majority of factors associated with alertness are modifiable and therefore amenable to behavioral interventions,” write Vallat et al.
The team is keen to investigate some of the mechanisms behind these associations to gather more precise data. Participants reported their levels of alertness, which were not measured using any scientific instruments.
That said, in addition to reporting their daily behavior, participants ate standardized meals and wore an accelerometer (to measure sleep and activity) and a continuous glucose monitor (to measure blood sugar levels after meals); which is better than most studies based only on questionnaires.
Another challenge for future studies will be to determine how and why sleeping more and sleeping later, relative to that person’s typical norm, enhances morning alertness – at least in this study. We know from other research that too much sleep can also affect well-being.
Improvements in sleep quality affect many other areas of our lives, most notably the safety of those working in jobs where mistakes can be fatal, including firefighters, nurses and airplane pilots.
“This question is scientifically fundamental, but also of societal importance, given that failure to maintain daytime alertness is a major causative factor in road traffic and occupational accidents, responsible for thousands of deaths each year,” the researchers write.
“Furthermore, insufficient sleep leading to reduced daytime alertness is estimated to be responsible for significant work-related productivity loss, greater health care utilization, and work absenteeism.”
The research has been published in Nature communications.