I've Had My Coffee, so Why Am I So Tired in the Afternoon?

Afternoon tiredness is to be expected, but undue low energy can be an indicator of sleep debt or circadian misalignment and is probably not because of your lunch.
Reviewed by
Jeff Kahn, M.S., Rise Science Co-Founder
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Woman feeling very tired in the afternoon while at work

Have you ever found yourself yawning through the middle of the workday? Or struggling to keep your eyes open after lunch? Afternoon tiredness is a common affliction that many people deal with daily. It can lead to you drinking an early afternoon coffee or eating a sugary snack to “boost” your energy levels, both of which are counterproductive to the goal of more energy, as we’ll go on to explain.

Afternoon tiredness is to be expected as part of the flow of your circadian rhythm, but excessive tiredness could be a strong indication that you aren’t getting the correct amount of sleep at night. Secondary or additional reasons could be that you’re suffering from circadian misalignment or a sleep disorder.

In this article, we’ll discuss why your energy levels naturally dip in the afternoon and what would cause you to feel more tired than usual. We’ll also discover some ways to gain back energy during the midday hours as well as how to make the most of the energy you have.

The Two Laws of Sleep

To begin understanding your energy levels overall and the natural cause of afternoon tiredness, we first need to examine the “two laws of sleep” - sleep debt and circadian rhythm - that govern your sleeping and waking habits. These two processes are the levers by which the RISE app helps you maximize and optimize your daily energy levels.

Sleep Debt

Sleep debt is the amount of sleep you’ve owed your body over the past 14 days. When you don’t get the optimal amount of sleep your body needs each night, it adds up to create sleep debt. The amount of sleep you need is genetically determined and thus unique to you, as not everyone needs eight hours to function optimally. The average sleep need is 8 hours and 10 minutes, give or take about 44 minutes. A percentage of the population (13.5%) may need a longer sleep schedule of 9 hours or more. 

Paying back that sleep debt, i.e., getting in more hours of sleep than your biological nightly need, is an important step to get the maximum possible energy in the day. The higher your sleep debt is, the more diminished your energy potential.

Excess sleep debt can lead to cognitive impairment and poor judgment calls, just the same as if you were inebriated. The good news is that you can lower sleep debt by making up for the missing hours. Using a tool like RISE to track your sleep debt and create healthy sleep habits to keep sleep debt low is the first step to having more energy in the afternoon.

RISE app screenshot showing how much sleep debt you have
Using a tool like RISE to track your sleep debt and create healthy sleep habits to keep sleep debt low is the first step to having more energy in the afternoon.

Circadian Rhythm

You’ve undoubtedly heard the term “circadian rhythm” before in the context of early birds and night owls and their sleep patterns. But what exactly does it mean, and how does it impact your energy levels, especially in the afternoon?

The circadian rhythm is your body’s internal clock. It dictates your ideal sleep-wake cycle, much of your biological functioning and behavior, and your energy fluctuations throughout the day. Within a roughly 24-hour period, your internal clock will take you through the active and inactive patterns of the day. These patterns can be used to help you understand the best times for both high-energy tasks and relaxing tasks to get the most out of your days.

The basic pattern of your circadian rhythm works like this:

  • Wake up: Slight grogginess for about 90 minutes after waking up (also known as sleep inertia).
  • Morning peak: Your first window of alertness and energy.
  • Midday dip: A predictable dip in energy in the early to mid-afternoon, depending on your chronotype.
  • Evening peak: Your second window of alertness and energy, sometimes referred to as a “second wind.”
  • Wind-down: Feeling less alert as sleep pressure builds, occurs 60-90 minutes before biological night.
  • Melatonin Window: A roughly one-hour period during which the brain is producing its highest levels of the sleep hormone melatonin. This is the ideal time to go to bed to fall asleep quickly and stay asleep throughout the night.

Working with your circadian rhythm instead of against it is the backbone of good sleep hygiene. Working against it by staying up later than your Melatonin Window or getting up earlier than your chronotype indicates (a common problem for night owls living in an early bird world) can lead to circadian misalignment, which can not only lead to serious health problems like insomnia or mood disorders over time but social jetlag in the near-term. In fact, social jetlag could lead to the feeling of undue tiredness you might experience in the afternoon. The RISE app charts your personal circadian rhythm so you can anticipate your peaks and dips and know the best time for you to wake up and fall asleep so you can stay in circadian alignment.

RISE app screenshot showing your energy peak and dip times
The RISE app charts your personal circadian rhythm so you can anticipate your peaks and dips and know the best time for you to wake up and fall asleep so you can stay in circadian alignment.

Pulling the Two Laws Together

Now that you understand the concepts of sleep debt and the circadian rhythm, we can start to talk about bringing the two together to help you solve your afternoon tiredness. While a slight ebb in your energy in the afternoon is your circadian rhythm working as expected, minimizing your sleep debt (0-5 hours is where you’ll feel and function your best) and sticking to your natural circadian rhythm is the bedrock of feeling less tired in the afternoon.

That’s because, while sleep debt and circadian rhythm work independently (your energy will ebb and flow regardless of how much you sleep), they are also interrelated. The less you sleep, the deeper the energy trough in the afternoon and the duller the energy peaks. The opposite is also true. Keeping your sleep debt low is key to feeling as little tiredness in the afternoon as possible. 

Making the Most of Your Afternoon Energy

As mentioned, some level of afternoon tiredness is normal to experience. The more intense your sleep debt, the more tired you’ll feel during this time. While you work to pay back your debt (5 hours or fewer will have you feeling and functioning your best), there are ways to take advantage of your daily energy schedule to feel like you’re getting more done. 

Recall the basic pattern of your circadian rhythm above. During your two daily energy peaks you’ll feel most capable and clear-headed, so use this time for challenging or important tasks. Examples include: leading an important meeting, having a difficult conversation with a client or colleague, and harnessing your creativity for writing or design projects. Evening peak time is also ideal for nurturing your relationships and hobbies, or tackling your home to-do list, for a healthy work-life balance.   

Your afternoon dip meanwhile is best used for low-stress work and recharging. Schedule lower capacity administrative work, webinar watching, or expenses during this time. If you’re WFH this is also a good time for a workout, or household chores, and the best time for a nap!

The RISE app’s new calendar integration lets you synchronize your energy peaks and dips with your Apple or Google calendar. With your daily activities and circadian data in one place, it is now easier to adjust your schedule to be effective personally and professionally. These blocks on your calendar also let others on your team at work know when you're best suited for particular activities.

RISE app screenshot showing calendar integration
RISE’s new calendar integration lets you synchronize your energy peaks and dips with your Apple or Google calendar to be more effective personally and professionally.

Underlying Medical Conditions

You should also make sure that there are no underlying medical conditions that could be attributed to your low levels of energy in the afternoon. Lack of sleep and low energy can be symptoms of serious medical conditions. Those could include depression, heart disease, diabetes, and much more. If you pay back your sleep debt and practice circadian alignment and still don’t notice any changes, you might want to consider speaking to your doctor about other possible reasons behind your low afternoon energy.

6 Quick Do’s and Don’ts To Relieve Afternoon Tiredness

Reducing your sleep debt and working with your circadian rhythm are essential steps to having more energy and less of an afternoon slump. However, fixing your sleep debt takes time and won’t be the immediate pick-me-up you need for your next afternoon meeting.

For a quicker energy fix, here are our recommended do’s and don’ts:

1. Respect Your Caffeine Cutoff

Your drinking habits can have a major impact on your afternoon energy levels. One way that many people try to relieve afternoon tiredness is with caffeine, but ill-timed caffeine makes it difficult to get a good night’s sleep, which then impacts your next day afternoon energy.

Don’t enter the vicious cycle of caffeine and sleep loss. Caffeine is merely a mask for low levels of energy and sleepiness. Caffeine late in the day can make it hard to fall asleep that night, meaning you’re likely to be sleep deprived the next day. That leads you to be more likely to reach for more caffeine, ensuring escalating sleep debt and an unhealthy, vicious cycle of sleep deprivation and caffeine dependency.

The RISE app can tell you exactly when the best time is to cut off your caffeine intake based on your unique biology. You can even set reminders in the app to notify you when it’s time for your cup of coffee last call. We cover more on when to have your last cup of coffee here.

RISE app screenshot telling you what times to limit caffeine
The RISE app can tell you exactly when the best time is to cut off your caffeine intake based on your unique biology.

2. Eat a Healthy Diet

Your eating habits, especially at lunch, can also incite afternoon fatigue. Carb-heavy lunches and a lack of protein can limit your energy and make your natural afternoon dip feel more draining than it should be. Lunches with a mix of proteins, healthy grains, and healthy fats can give you real energy to power your afternoons and avoid a blood sugar rush and subsequent crash.

3. Nap for the Right Amount of Time at the Right Time

Napping isn’t just for kids! Sleeping during the day can help you boost your energy levels and reduce your sleep debt without having to go to bed early. However, naps that are too long can lead to sleep inertia. In contrast, short power naps of 10-20 minutes can help you feel energized when you wake up. 

The RISE app can help you determine exactly when to time your naps in accordance with your circadian rhythm – the afternoon dip is the best time for you to nap so you can still get enough sleep later that night.

4. Hydrate

Water is a quick solution that can work as an energy booster. It helps your body function more effectively and hydrates your cells. Healthy, hydrated cells help your internal systems run smoothly and provide your brain with liquid energy. The CDC recommends letting your natural thirst help dictate your intake — roughly eight eight-ounce glasses of water throughout the day.

Just make sure you avoid drinking water right before bed. That can lead to reduced sleep quality which in turn can lead to increased sleep debt.

5. Take a Quick Walk or Do Some Light Exercise

Taking a walk and getting outside is great for getting light during the day, which is an often overlooked part of sleep and circadian health. It will also help with blood flow in your body and “wake up” your muscles and brain.

6. Avoid Driving

Some people claim that driving helps them stay awake. However, driving while tired or sleep-deprived can be extremely dangerous. In fact, drivers who have less than seven hours of sleep at night increase their odds of crashing. Up to one-fifth of all fatal crashes involve a sleep-deprived driver. Tiredness impacts your judgment and decision-making abilities, your reaction times, and your focus.

If you are experiencing drowsiness in the afternoon, consider carpooling with a coworker or taking the bus home rather than risking driving yourself. And, once you get home, make sure that you stay in! Catching up on sleep to reduce your sleep debt makes driving and traveling safer for you and others on the road.

How the RISE App Can Help

While some afternoon tiredness is to be expected, you can have more afternoon energy by keeping your sleep debt low and working with your circadian rhythm. RISE tracks your debt, helps you pay it back, and helps you make the most of your afternoon – and the rest of the day as well – by predicting your energy schedule and aligning tasks to times of day.

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