How to beat that afternoon slump
That afternoon slump, it’s an all too common complaint. You may find that you're reaching for that second (or third) caffeine hit for the day, something sugary to pep you up, or you may just dwindle an hour or trying to find the energy to get through that last slog of work.
In truth, there are a few factors at play here... The afternoon slump is a culmination of your body’s natural rest-activity cycle, sleep quality, external exposures, dietary intake, physical activity levels, and mental stressors. Being aware of all these factors and building in some daily habits can help prevent this slump without reliance on those stimulants.
Here is a breakdown of the main culprits and some ways to overcome them:
1. Rest-activity cycle:
While we’re all aware of our circadian rhythm that dictates our sleep-wake cycle, we also have a shorter cycle that governs our rest and activity levels throughout the day. This cycle is thought to be roughly 90 minutes long (although it may vary from 80-120 minutes) and it is a transition from different levels of excitable to restful states and then back (1,2). You will feel most alert at the peak of the excitable wave, and conversely, the most drowsy at the trough of the wave. For most people, a trough tends to hit between 1-3 pm and is largely responsible for that slump when compounded by other factors.
Solution: You can find your rest-activity pattern by taking note of when you feel dips of alertness or tiredness throughout your day.
Keeping a simple journal for 3 days logging the times you notice cues of tiredness like yawning or a lapse of concentration, and then take the average of all these times (2). You can then use this information to schedule work or tasks that require a high level of concentration to your wave “peak” and build on some habits such as balanced snacking, getting outdoors, and gentle movement into the troughs.
2. Inadequate protein and fibre at breakfast and lunch
As far as satiety goes, protein and fibre are our heroes. They have the ability to slow gastric emptying and keep blood sugar balanced throughout the day helping to mitigate those low-energy periods. What we eat in the first half of the day has a profound effect on energy levels throughout the afternoon and evening, so inadequate protein and fibre particularly at breakfast and lunch, can leave you hungry and lacking energy - an effect that can accumulate over the days and weeks.
Solution: Focus on including good quality protein foods at breakfast and lunch then build the rest of your meal around this. Ideally, your breakfast and lunch should include a palm-sized portion of high-quality protein foods coupled with a source of fibre-rich vegetables or whole grains or legumes.
3. Refined carbohydrates at lunch
While carbs are having a bit of bad press lately, there is certainly a distinction between whole, complex carbohydrates that should be included in a healthy diet and the refined and ultra-processed ones that can cause issues.
Refined carbohydrate foods like white bread and grains, cakes, sweets, pastries that are so abundant in the western diet, are quick to digest and deliver glucose to the blood rapidly. This results in a brief rise and then a drop in blood sugar and subsequent energy levels. On top of this, refined carbohydrate foods tend to be void of the nutrients found in their whole-grain counterparts, many of which are beneficial to cognitive function.
Solution: Include whole-grain and complex carbohydrates at lunchtime like fruit, brown rice, whole wheat bread, or legumes. Carbohydrates should make up a quarter of your meal equating roughly to 1 cupped handful.
While it is always encouraged to choose unrefined carbs, it’s not to say the less nutritious versions should be completely avoided. If on occasion you choose to have these, it’s best to avoid eating them “naked”. Pairing fast absorbing carbohydrate foods with healthy fats like olive oil, nut butter or avocado will help to stabilise that rapid blood sugar rise.
4. Not enough movement and sunlight
Tying back to the rest-activity cycle, a lack of movement particularly during the low-energy periods of the day can play into the restful wave by allowing your body to relax a little too much. If you happen to work in a poorly lit environment or have little exposure to sun and fresh air, this can further exacerbate that sluggish feeling. Light exposure (particularly natural light) has a powerful effect on the circadian rhythm and alertness as sunlight is known to reduce melatonin production (sleep hormone) and maintain serotonin levels (mood-boosting hormone) (3,4).
Solution: Make an effort to get up from your desk and walk around or stretch every half hour. During that afternoon slump, schedule tasks that require movement or work from a standing position if it’s available to you. Make an effort to go outside throughout the day for 10-20 minutes of sun exposure - ideally breaking up your day by taking your lunch break outside and eating away from your desk.
5. Caffeine reliance
We all know that caffeine provides us with that instant hit of energy and cognitive stimulation, but caffeine has a half-life of 5 hours meaning it takes 5 hours for caffeine to wear off by half in the body (5). Depending on the efficiency of your metabolism this can even extend up to 9.5 hours, so consuming too much caffeine or drinking it too late in the day can disrupt the quality of your sleep. The boost we get from caffeine also can mask our natural hunger cues effectively acting as an appetite suppressant. The result of this is under-fueling the body with the energy it needs to remain active throughout the day.
Solution: Coffee has a host of health benefits but ideally it should be limited to no more than 1 or 2 cups. It should only be consumed in the first half of the day so it doesn’t disrupt your sleep and energy levels the next day as a result of bad sleep. If you find that you are replacing snacks or meals with coffee then it's worth trying an alternative like herbal tea and focus on fueling with food instead.
6. Dehydration
Even mild dehydration can cause fatigue, headache, and suppress mood and focus. Many of us simply forget to drink enough water throughout the day, and while it's not recommended to force ourselves to drink beyond thirst, we can quickly become dulled to our natural thirst cues.
Solution: Keep a large water bottle within reach, sipping constantly throughout the day and a full glass at mealtimes. Men should aim to drink 2.6 L/day (about 10 cups) and women 2.1 L/day which is about 8 cups (6).
Proper nutrition, fitness, sleep, and stress management are ultimately the driving force behind stable energy levels and heightened cognitive function. So along with these daily habits, I encourage you to develop overall health and wellbeing with a focus on balanced eating, daily movement, good sleep hygiene, and stress management.
If you experience more chronic fatigue or drastic drops in energy levels throughout that day, then optimising your diet and lifestyle is the next step for you!
The Med Reset online course is your step-by-step guide to boost your energy, and moods and reach your healthy weight using the science-backed principles of the Mediterranean diet.
References:
1. LaJambe, C. M., & Brown, F. M. (2008). Ultradian Cognitive Performance Rhythms During Sleep Deprivation. In D. Lloyd & E. L. Rossi (Eds.), Ultradian Rhythms from Molecules to Mind: A New Vision of Life (pp. 283–301).
2. Wilson. K. (2020). How to build a healthy brain. Yellow Kite Publishing.
3. Brown, G. M. (1994). Light, melatonin and the sleep-wake cycle. Journal of Psychiatry and Neuroscience, 19(5), 345–353.
4. Effects of Light on Circadian Rhythms | NIOSH | CDC. (2021, June 28). https://www.cdc.gov/niosh/emres/longhourstraining/light.html
5. Research, I. of M. (US) C. on M. N. (2001). Pharmacology of Caffeine. In Caffeine for the Sustainment of Mental Task Performance: Formulations for Military Operations. National Academies Press (US).
6. National Health and Medical Research Council. (2014, March 17). Water [Nutrient Page]. https://www.nrv.gov.au/nutrients/water