15 Jan The Key to Waking Up Refreshed
Why is it that some people bounce out of bed in the morning while others need six alarms and a red bull? If you’re getting enough sleep but still feeling groggy in the morning it can be tempting to blame bad genetics. After all, what other reason could there be? In the age-old debate of nature vs nurture, morning alertness has been under investigated, however a recent study by Vallat et al at the University of California may shed some light on this relationship.
They investigated three hypotheses; that longer sleep duration would increase alertness, exercise the day prior would increase alertness and that alertness would vary with morning meals of varying nutritional composition. Over a two-week period 833 individuals reported on their exercise habits and sleeping patterns while following a standardised nutritional plan that varied between groups. Subjects were fitted with a continuous glucose monitor and accelerometer wristwatch to measure these factors. This was then correlated with self-reported alertness to determine if lifestyle factors directly related to wakefulness. A key factor of the study was the inclusion of paternal and fraternal twins to determine if there was a genetic component to this.
The results showed that individuals who slept longer had increased morning alertness, particularly those who slept later into the morning. The researchers postulated that this may be due to the increased likelihood of waking up during circadian assent versus nadir, reducing sleep pressure and increasing the duration of time spent in REM sleep. Individuals who reported exercising the day prior reported greater alertness also. This factor was independent of age, however the impact of exercise on sleep requires further investigation. The standardised morning meal that produced the greatest alertness was a high-carbohydrate, low-sugar breakfast, though this varied based on individual metabolic profile. Primary author of the paper, Raphael Vallat, explains this;
“A breakfast rich in carbohydrates can increase alertness, so long as your body is healthy and capable of efficiently disposing of the glucose from that meal, preventing a sustained spike in blood sugar that otherwise blunts your brain’s alertness,”
Comparison of findings between twins found that only 25% of the differences in daytime alertness between individuals could be explained by genetics. This suggests that while your genes may contribute in part to the way you wake up, sleep, exercise and diet are far more influential.
Aside from affecting an individual’s everyday functioning and mood, reduced alertness is a serious socio-economic problem. It is the number one cause of motor accidents worldwide, accounting for more than 100, 000 incidents and 1,500 deaths in the US annually. According to senior author and professor of neuroscience Matthew Walker:
“Many of us think that morning sleepiness is a benign annoyance. However, it costs developed nations billions of dollars every year… As scientists, we must understand how to help society wake up better and help reduce the mortal cost to society’s current struggle to wake up effectively each day.”
The key takeaway from this paper is that if you are someone who finds it difficult to wake up in the mornings you are not beyond help and your genetics are likely not to blame. By making simple changes to your sleeping, eating and exercise habits you may be able to improve your day-time alertness.
Citation:
‘How people wake up is associated with previous night’s sleep together with physical activity and food intake’ by Vallat et al., of the University of California, Berkeley, published in Nature Communications on the 19th of November 2022
For more information read an article on the study at
https://www.sciencedaily.com/releases/2022/11/221129143811.htm or read the original study at https://www.nature.com/articles/s41467-022-34503-2