Physiology Friday #220: How to Wake Up More Alert
A successful morning routine starts the day before.
Greetings!
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On most days of the week, I wake up in the morning with excitement, motivation, and a positive outlook on the day. It might take me a few minutes to overcome the unavoidable sleep inertia, but after moseying around the kitchen for a bit and a few sips of coffee, I’m ready to go.
On the other days…waking up is a chore. The alarm goes off, and I barely budge. Rolling out of bed takes all of my energy, and I might even forget to press “on” on the coffee maker, spending minutes wondering why the familiar smell hasn’t yet percolated throughout the room.
What explains the huge gap in alertness from one morning to the next? Why, in the absence of any major lifestyle changes or an indulgence in alcohol-infused festivities on the previous day, does our morning alertness waver from one day to the next?
This is a problem that all of us would like to solve. Alertness in the morning is not only great for personal productivity, but it’s also crucial for public health and safety — reduced alertness is a significant contributor to traffic- and workplace-related injury and death.
Luckily, science can help provide us with some strategies that might help us wake up with more vigor each day.
A study published in Nature1 teased out the specific biological and lifestyle-related factors that contribute to morning alertness. This information can help us to “design” our lives to optimize our ability to wake up and establish a successful daily routine.
The influence of these factors was examined by investigating four different hypotheses:
The prior night’s sleep duration (length of sleep) and sleep efficiency (percentage of time spent asleep versus time spent in bed) would predict higher next-day alertness
Being more active (exercise or physical activity) the day prior would predict higher next-day alertness
The composition of one’s breakfast (percentage of carbohydrates, fat, and protein) and the blood glucose responses to breakfast would influence morning alertness
Morning alertness would be influenced by genetics
Participants involved in the study were asked to provide an “alertness level” each morning of their participation. The average of the initial morning alertness ratings (beginning at breakfast and lasting for 2.5 hours after breakfast) was used to calculate an “alertness score” for each participant.
Results
Sleep and morning alertness
Sleeping longer than usual and waking up later than usual were both associated with being more alert the next day.
Physical activity and morning alertness
Higher levels of physical activity during the day prior were associated with higher next-day alertness. However, when high levels of physical activity occurred at night on the day before, morning alertness the next day was worse.
Breakfast and morning alertness
Having a breakfast higher in carbohydrates was associated with higher morning alertness, while a high-protein breakfast predicted lower morning alertness. This effect wasn’t dependent on caffeine intake — meaning that caffeine didn’t seem to modify morning alertness for any of the breakfasts.
How someone responded to breakfast also predicted their morning alertness. A high post-breakfast glycemic response was associated with lower post-breakfast alertness, and vice-versa.
Interestingly, when participants consumed a breakfast of pure glucose (performed an oral glucose tolerance test as part of the study), their morning alertness was the lowest of all recorded values. The sugar crash helps noone.
Next, each participant’s typical alertness level was calculated. In other words, on most days, how alert or not does someone tend to be? This individual alertness level, referred to as their “trait daytime alertness”, was then used to find which lifestyle factors were most influential in determining someone’s morning alertness.
Four factors stood out: mood (happiness), age, sleep, and eating frequency.
Specifically, being happier, being older, and having better sleep quality were each associated with having higher levels of morning alertness.
Eating more meals throughout the day predicted lower morning alertness. Participants who ate 1–2 times per day had significantly greater morning alertness levels compared to participants who ate 3–4 times per day and those eating 5 or more times per day — who had the lowest levels of morning alertness.
A genetic influence on morning alertness?
The lifestyle factors predicting morning alertness were found to explain about 59% of the variability in someone’s overall morning alertness levels — leaving room to speculate that heritability (i.e., genetic factors) may also play a role.
An individual’s daytime and morning alertness were not strongly influenced by genetics.
However, factors including sleep duration, sleep efficiency, and sleep onset seemed to have a strong genetic contribution.
This may have been one of my favorite studies to read in quite some time, not because it provides any necessarily novel information (sleep, activity, and diet are all important…duh), but because it can provide some specific advice that everyone can implement.
Based on the results of this study, we can formulate some actional strategies to improve our morning alertness levels:
Sleep longer than normal, and let yourself “sleep in”: increased morning alertness was associated with longer-than-average sleep duration and later wake-up time. If you normally get 7 hours, sleep 8. If you normally wake up at 5:30 am, set the alarm to 6:00; your alertness may benefit.
Be more physically active the day prior, but ensure most of the activity occurs during the day: daytime activity improved morning alertness levels, while nighttime activity seemed to reduce alertness. This may have to do with late-night activity impacting sleep architecture and increasing sleep disturbances.
Eat a higher(er) carbohydrate, low(er) protein breakfast: this isn’t to say that having a few Pop-Tarts will optimize alertness levels, nor that a few eggs will cause alertness to tank. But a breakfast composition skewed more toward carbohydrates seems to enhance alertness, so long as your blood-glucose response afterward isn’t too drastic.
Moderate your morning glucose (see above): the impact of your breakfast on glucose can be modulated by exercising before or after — both of which will dampen your blood glucose response to the meal.
Eat less often: if you’re a 1–2 meal per day type of person, the data suggest that this may contribute to better morning alertness, while frequent eating (3–5 times/day) seems to reduce next-day alertness.
It’s important to point out that none of the above factors or recommendations will apply to all of us. The general advice gleaned from studies like this isn’t a one-size-fits-all approach to lifestyle modification, but it sure can help steer us in the right direction.
More importantly, however, this study indicates that how well we wake up is under our control!
Waking up in the morning bright-eyed and ready to tackle the day is a superpower. The neat finding of this study is that this “superpower” isn’t something we’ve inherited, but something that we can access through simple lifestyle modifications.
Thanks for reading.
See you next Friday.
~Brady~
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We suck at this in the Western world, but smaller portions and leaving the table only 80% full (the Japanese/Confucian wisdom of "Hara Hachi Bu") feels so much better than eating too much. You're more alert, lighter, and feel full of energy which is exponentially better than that lethargic, lazy feeling after over eating.
Great takeaway section here, Brady. Thanks for writing.