Imagine shining a flashlight at a wall in a dark, empty room. If you walk toward the wall, the light will contract. The closer you get to the wall, the smaller and more concentrated the beam of light becomes. By the time the flashlight is an inch from the wall, you’ll see a tight, bright circle of light surrounded by shadow and darkness.
Your attention is a lot like the beam of that flashlight. You can focus it closely and intensely on something, or you can relax it — allowing it to grow soft and diffuse. A lot of research — much of it recent — has examined the different types and qualities of attention and their associations with mental health and cognitive functioning.
This work has revealed that certain types of attention may tire out your brain and contribute to stress, willpower failures, and other problems. Meanwhile, activities that broaden and soften your attention may reinvigorate your brain and promote psychological and cognitive wellbeing. Whenever you train your attention on something — an act that cognitive scientists sometimes call “directed attention” — this requires effort.
More effort is needed when other things (i.e. distractions) are vying for your attention, or if the thing you’re trying to focus on is boring. According to a 2016 review from researchers at the University of Exeter Medical School in the U.K, your ability to effortfully focus your attention is finite. Just as an overworked muscle grows weak, overworking your attention seems to wear it out.
When that happens, a lot can go wrong. For one thing, your ability to concentrate plummets. Your willpower and decision-making abilities also take a hit. According to a 2019 study in the journal Occupational Health Science, attention fatigue may also contribute to stress and burnout.
There’s even some work linking attention fatigue to attention deficit hyperactivity disorder (ADHD). “The symptoms of ADHD and ‘attention fatigue’ so closely mirror each other that the Attention Deficit Disorders Evaluation Scale has been used as a measure of attention fatigue,” wrote the authors of a 2004 study in the American Journal of Public Health…..
Waking up already feeling worn out? Unable to overcome the afternoon slump? These may be signs that various lifestyle factors are taking a toll on your energy levels, leading to brain fog and straight-up exhaustion.
When constantly on the go, it may be difficult to find ways to recharge. However, Dr. Alfred Tallia, professor and chair of the Department of Family Medicine and Community Health in the Robert Wood Johnson Medical School, explained that more often than not, low energy levels can be remedied by adopting simple changes to your daily routine.
So, how can you combat unchecked stress to boost your energy levels? Vasan explained that it’s crucial to “find ways to integrate meditation or mindfulness into your daily life,” even for just five minutes each day. Experts also say that identifying coping skills that work for you — such as journaling or reading something that brings you joy — can help you destress and feel more energetic.
“If you’re consuming large amounts of caffeinated beverages throughout the day, it is probably going to affect your sleep pattern. This can then affect your energy levels,” Tallia said.
It’s important to note that suddenly cutting back on caffeinated beverages can also leave you feeling tired at first. As Tallia explained, “the body gets used to caffeine as a stimulant, and when it’s not present, you can experience an energy slump.”
Practice good sleep hygiene and establish a routine.
It goes without explaining that catching enough Zzzs is key to boosting your energy throughout the day. However, your energy levels are not just impacted by the amount of sleep you get each night, but by the quality of that sleep.
Even when practicing good sleep hygiene, you may find you’re waking up feeling fatigued. Raelene Brooks, the dean of the College of Nursing at University of Phoenix, said that could point to a sleep disorder such as sleep apnea. If you suspect you have a sleep disorder, don’t hesitate to pay your physician a visit.
“Even low-impact movement is shown to increase your oxygen flow and hormone levels, which give you a boost of energy,” Vasan explained. “It is the No. 1 tip I recommend to anyone feeling fatigued.”
Drink more water.
Dehydration is a common cause of low energy. According to Brooks, the science behind this is quite straightforward: “Our red blood cells carry oxygen. Ideally, a plump and round red blood cell allows for a full oxygen-carrying capacity,” she said. “When we are dehydrated, the red blood shrinks and this decreases the capacity for the cell to carry a full load of oxygen. Low oxygen levels are manifested by fatigue, irritability and restlessness.”
If you struggle with being mindful of your water intake, consider trying hacks such as investing in a smart water bottle to ensure you’re drinking enough H2O every day.
Be mindful of your screen time during the evening hours, and also during the day.
It almost goes without saying that excessive screen time at night can mess with your natural sleep cycle and energy the following day. As Vasan explained, “spending too much time on your phone, computer or watching your TV can cause fatigue by disrupting the neurotransmitters that are essential for sleep and restoration.”
However, the time you spend looking at your phone or computer during the day can also have a harmful impact on your energy levels. Too much screen time can lead to eye fatigue, which may trigger headaches and make it more difficult to concentrate.
We live in a digital world, so spending extensive time looking at a screen is unavoidable for most people. Making the “20-20-20 rule” a habit is a step towards tackling tiredness. According to Harvard Business Review, “when you’re working on a laptop, take a break every 20 minutes. Look at an object 20 feet away for 20 seconds to give your eyes a chance to relax.”
Avoid skipping meals.
If you ever skipped breakfast or worked right through your lunch break, you probably noticed you feel groggier than usual. While it’s totally normal to miss a meal, making a goal to regularly eat nutrient-rich meals and snacks throughout the day can increase your energy levels.
“Your brain needs nutrition to really function appropriately,” Tallia said. “A lot of people skip meals, and their blood sugar levels are going up and down all through the day.”
Moreover, Tallia said to steer clear of fad diets that encourage people to majorly cut back on caloric intake or to eliminate essential nutrient groups like carbohydrates. This can deprive you of energy. While it’s not uncommon to wake up feeling low on energy every once and a while, chronic fatigue could point to an underlying health issue.
“If you are eating well, getting enough sleep, integrating movement and exercise into your daily life but still feel tired for more than two weeks, you should consider reaching out to a medical professional,” Vasan said, explaining that a consistent drop in energy “can be an indicator of a host of mental and physical health issues ranging from fairly benign to severe.”
Ultimately, boosting your energy often comes down to taking inventory of different activities and current habits that could be draining you. Adopting just a few simple changes to your daily routine could be key to beating the fatigue once and for all.
When people ask me why I became a writer, I have plenty of reasons to list: Words bring me joy. I ask questions constantly. And when I hear a good story, I’ll repeat it again and again until my friends get tired of hearing it. But in July of 2021, these responses started to feel hollow.
I was burned out. “I feel like I sprained my brain,” I told my friend over the phone. When I wasn’t working, I felt fine; when I tried to use my head, it felt like putting weight on a bum ankle.
I know I’m not alone. At this moment, when work is isolating some people at home while putting others in danger, burnout seems particularly rampant. In a survey of 1,500 workers from Indeed in March 2021, 53 percent said they were burned out—up by nearly 10 percent from the previous year. Another survey of nearly 21,000 healthcare workers published that May in The Lancet found similar rates.
I wanted to regain my curiosity and the joy I find in language as soon as possible, so I reached out to scientists to find out what, exactly, was happening in my body—and what I could do to make it better.
Burnout is a phenomenon so old, they made a sin out of it, according to Gordon Parker, a professor of psychiatry at the University of New South Wales. Once called “acedia,” the eighth cardinal sin described a state of listlessness, apathy, and torpor observed in fourth century monks. “They would wake up one day and say ‘the sky is no longer blue,’” Parker said. These monks would stop getting pleasure out of life and would lose their faith in God.
They were more than just tired. They had forgotten the meaning of all that they did. And that pretty much describes burnout. The response to chronic stress goes beyond exhaustion; sufferers also experience a loss of idealism and feel like they’re bad at whatever they do. Those are the three prongs identified by the Maslach Burnout Inventory, the assessment most often used by psychologists to evaluate such mental fatigue.
And all that angst isn’t just in your head—it’s very much a physical phenomenon, rooted in the body’s stress-response system. Scientists studying the syndrome are particularly interested in the hypothalamic-pituitary-adrenal axis, also called the HPA axis. When we’re faced with a threat—say, a bear chasing us, or the prospect of responding to an ambiguously stern-sounding email—the HPA axis releases a hormone called cortisol. Cortisol helps the body run from whatever is threatening it; it raises our heart rate and helps our body harvest energy from glucose.
Cortisol also decreases activity in systems you don’t need when your life is in immediate danger, like the reproductive and immune systems. When the hypothalamus, a structure in the brain that acts like the control room for the HPA axis, detects high levels of cortisol in the blood, it’s supposed to say “okay, my work is done here,” and shut the stress response down.
Researchers can capture a snapshot of how the stress-response system is functioning with a test called the dexamethasone challenge. Dexamethasone is a drug that tells the hypothalamus to suppress the stress-response system. Given a dose of it, a healthy person should start producing less cortisol. But multiple studies have found that people with burnout have an altered response to the drug. Some studies find that those individuals don’t react to dexamethasone much, if at all—they continue pumping out more cortisol regardless.
Other researchfinds that people with burnout have an exaggerated response to the drug—they suppress cortisol more than the healthy controls do. Researchers hypothesize that these two seemingly contradictory findings represent two stages: burning out, and being burnt out.
“During the burning-out phase, the system is in overdrive,” Parker said. When stress is chronic, cortisol levels in the body keep going up, but the system doesn’t shut itself down. The burnt-out phase begins when that system is tapped out, says Renzo Bianchi, a psychologist at the University of Neuchâtel in Switzerland. “Your stress response gets so exhausted that you stop producing cortisol at high levels,” Bianchi said.
Cortisol may stress us out, but we also need the hormone to survive. It’s quite literally what gets us up in the morning. So when people enter this “burnt out” phase, they feel tired and cynical. They lose drive. They might even experience cognitive impairment and memory changes.
These symptoms might sound similar to clinical depression. But according to some scientists, including Christina Maslach of the Maslach Burnout Inventory, burnout and depression are not at all the same.
Burnout is a syndrome that may cause a person to become depressed; depression might predispose a person to burnout. But ultimately, burnout is distinct in that work is always at its root. People often feel better as soon as they’re able to get away from the cause of their stress, Parker said. That’s not usually the case with depression.
That distinction is important to make, because by treating burnout as an illness—like depression or an anxiety disorder—we risk offering the wrong solutions, Maslach said. You can’t self-care away your burnout, she added. It’s not so much about the individual as it is the situation they’re in. You have to remove the cause of your stress, and that often requires structural changes in the workplace.
That was disappointing for me to hear. When I reached out for expert advice, I’d already spent several of the preceding months focused on getting more sleep, running more often, and trying to take short vacations. All of these habits support good mental health, and might even offer short-term relief, Bianchi says—but they don’t get at the root cause of burnout. You can take all the time off you need, he says, but without identifying the root causes of your stress, you’ll eventually return to the same place.
In scientific literature that investigates risk factors for burnout, six come up again and again, according to a review co-authored by Maslach and published in the 2016 book Stress: Cognition, Emotion, and Behavior. There’s workload, the amount of autonomy you have, and fairness in the workplace. Then there’s reward—how much your work is recognized and compensated—and workplace community, or the social support you receive from colleagues or clients. Finally, values and meaning: whether or not the work you’re doing syncs up with your ideals.
Employers have the power to prevent burnout by creating a fair and supportive workplace, Maslach says—one where people feel like they have autonomy and are able to cope with their workload. But people with burnout may need to troubleshoot which factors are negatively impacting them so they know how to take action on their own. For some people, Maslach says, curing burnout might necessitate moving organizations or switching fields entirely.
That wasn’t my route. Instead, I worked through Maslach’s six risk factors like a checklist. The more I thought about it, the more I came to believe that my work load itself wasn’t the main problem; instead, I realized that it had been a long time since I’d thought about what had initially excited me about journalism—talking to scientists, love for the craft of writing itself, the thrill of finding a new story—in other words, my values.
I created spreadsheets of topics that intrigued me, scientists I loved speaking to, and projects I had long put on the back-burner. Then, I brainstormed ways to make time for them, blocking off chunks of time for tasks like going down internet rabbit holes in search of stories.
While I expected the answer to involve loads of rest, curing my own personal case of burnout turned out to be a lot of work. But it was worth it. Three months after starting this research, words excite me again. I’m back to annoying my friends with facts about frogs and physics. And several times a week, without fail, I spend an afternoon in the coffee shop around the corner to work on my personal creative projects.
Nine months ago, before my burnout began, I told a friend “I feel like I have the best job in the world.” By getting to the root of my stress, I’ve managed to get that feeling back again.
By: Isobel Whitcomb
Isobel Whitcomb is a freelance health and environmental journalist based in Portland, Oregon. Passionate about covering the intersection of science and the human experience, they cover everything from wildfire to chronic pain. Her work in Popular Science focuses on exploring the wellness industry and debunking health misinformation.
It’s a familiar feeling on a Friday evening. After finishing a gruelling day’s work, you finally agree with friends on where to meet for a night out. But by the time you have figured out what to wear and where you left your keys, a night on the sofa begins to sound more appealing than one on the tiles.
Now, scientists think they may be able to explain why you feel so weary before you have even reached the bus stop: your brain has slowed down to manage the strain. The brain could suffer from something similar to the painful buildup of lactate in muscles during physical exercise. This could be why hard mental yards – and resisting the temptation to give up throughout the day – feel equally taxing.
Prolonged mental activity leads to the accumulation of a potentially toxic neurotransmitter in the prefrontal cortex, according to a study published in Current Biology. The researchers suggest the brain slows down its activity to manage the buildup, offering an explanation to why we feel tired.
“Even when you resist scratching an itch, for example, your brain is exerting cognitive control,” said Antonius Wiehler of the Paris Brain Institute, the first author of the study. Repeated demands on cognitive control functions can lead to fatigue, he said. The prefrontal cortex is the region of decision-making and cognitive control, which is applied when the brain overrides an impulse or fights any kind of temptation.
The team monitored the brain chemistry of 40 participants while they completed repetitive tasks on a computer. They formed two groups, who performed either hard tasks or easy tasks for over six hours. The researchers measured levels of a neurotransmitter in the prefrontal cortex. They found a greater accumulation of glutamate in participants who were given the harder tasks.
Work that involves a lot of thinking requires the brain to repeatedly resist the temptation to do something less demanding. Unsurprisingly, this can leave people feeling tired, but the brain chemistry behind it has remained unclear. Now, researchers suggest cognitive control may lead to the accumulation of glutamate in the brain – of which high levels can be harmful because it overexcites neural cells.
“We found that glutamate was accumulating in the region of the brain which controls the tasks we set participants,” said Wiehler. “Our understanding is that the brain has some kind of clearance mechanism to counteract this, which may slow down activity.” The researchers posit that mental fatigue could be linked to recycling the glutamate that builds up during neural activity. “The accumulated glutamate needs to be cleared away, which we think is likely happening during sleep,” said Wiehler.
When participants were asked to report their level of fatigue, no definitive link between glutamate and fatigue was found – the groups performing hard and easy tasks recorded the same tiredness. Researchers said this could be due to fatigue being subjective, and those doing the easy task were unaware of the difficulty of the other.
“The fact that glutamate levels don’t track the reported fatigue is slightly disappointing, but not surprising because there is often a dissociation between biological features and self-reported fatigue,” said Dr Anna Kuppuswamy from the Institute of Neurology at University College London, who was not involved in the study.
The researchers monitored only glutamate but suggest other related substances could be linked to fatigue. “The study measures a single neurotransmitter in a very specific part of the brain, so we have to look at it more globally,” said Kuppuswamy.
But the results were encouraging, she added. “We know that during physical exercise lactate accumulates in the muscles, leading to muscle fatigue. It is kind of intuitive that something similar happens in the brain and this is good first evidence to suggest that.”
Mental exhaustion is a feeling of extreme tiredness, characterized by other feelings including apathy, cynicism, and irritability. You may be mentally exhausted if you’ve recently undergone long-term stress, find it hard to focus on tasks or lack interest in activities you usually enjoy.
Mental exhaustion often happens as a result of overuse, like physical overuse injuries. Even though you can’t point to it, it has more in common with repetitive stress injuries, like carpal tunnel or tennis elbow. Rather than overstressing a muscle group, mental and emotional exhaustion come from overstressing your mind.
Mental exhaustion is completely possible and is probably more common than it should be. After a long period of stress or time of intense emotions, mental exhaustion is bound to happen. Just like our bodies show symptoms after we push too hard, our minds are bound to display signs of mental exhaustion if we don’t take proper care.
Mental exhaustion can be caused by many things. Typically, though, people feel mentally tired after experiencing long-term stress. This is especially true if the stressors increase a person’s cognitive load or reduce their resources.
For example, you may be responsible for completing a challenging project with many moving parts and tradeoffs. This would require a high level of project management skills and political savvy (e.g., increased load).
Another example would be traveling for work. Constantly changing time zones would leave you feeling jet-lagged (reduced resources). Many stressors involve both reduced resources and increased load.
Work travel to an unfamiliar country where you don’t speak the language amps up the cognitive load. Taking care of a sick family member may involve coordinating medical care and interpreting unfamiliar terms while managing emotions (increased load). But you may also be getting less sleep (reduced resources). Over time, increased responsibility and stress plus poor self-care can result in mental exhaustion.
Though a wide variety of stressors can cause you to feel mentally drained, we’ve boiled down the 7 most common causes of mental exhaustion below.
1. Chronic stress
This is the most frequent cause of mental exhaustion. Chronic stress keeps your brain — and body — on high alert all the time. Over time, this begins to wear away at your well-being. Chronic stress can also lead to empathy or compassion fatigue. It can become difficult to muster an emotional response to the constant strain.
The human stress response was designed to work efficiently in the face of short-term stress (think fight-or-flight). However, it’s a much less effective response to a constant, nagging feeling of uncertainty. Unfortunately, uncertainty has become far too normal of a feeling since the start of COVID-19 pandemic. This has made mental exhaustion more common than ever.
3. Work stress
Stress at work can take many forms. It can arise from a values mismatch, difficulty managing tasks and priorities, or a high-demand, risk-oriented job. Some jobs (or programs of study) involve a lot of new learning. They could also require processing and making sense of a lot of information. Whatever the reason, it’s not always possible to leave work at work. Left unchecked, workplace stress can even evolve into burnout. Your work stress could bleed into your weekends and ultimately, develop into a bad case of the Sunday scaries.
4. Family issues
Few things are more stressful than worrying about a family member. Being a caregiver for young children, sick relatives, or aging parents can be mentally taxing. Even if everyone’s healthy, families can bring all kinds of stressors. Divorce, disagreements, and estrangements have a way of following you into all areas of your life. Ultimately, family troubles can be a big cause of mental exhaustion.
5. Juggling multiple commitments
In addition to caring for family, many people have other commitments on their plate — those commitments come with details, schedules, logistics, and challenges. Balancing an intensive school or training program, a second job, or a freelance business can leave you feeling like you’re never “off.” If you’re not able to, or don’t know how to, manage your priorities, you’re at risk of becoming mentally drained.
6. Emotional stress
There are dozens of things that can cause emotional stress. No matter the cause, the experience is similar. Constant negative feelings, events, and circumstances can make it difficult to relax. This emotional exhaustion can quickly lead to mental fatigue.