- A review of 11 studies published in the journal Sports Medicine found that when you’re mentally fatigued, your overall performance in endurance workouts and high-performance sessions—like a long run or hill repeats—is negatively impacted.
- To prevent mental fatigue, running first thing in the morning, practicing deep breathing exercises, or even taking a quick swig of a sports drink could help.
Scroll through social media or turn on the news, and you’ll see widespread Key Strength Training Exercises for Runners Have a calm commute coronavirus pandemic. While there’s no question that it’s important to stay informed about what’s going on, these habits can be mentally draining. And when you lace up for several miles in this state of mind, research shows that your workout suffers.
A 2017 review of 11 studies published in the journal Sports Medicine found that when you’re mentally fatigued, your overall performance in endurance workouts and high-performance sessions—like a long run or hill repeats—is negatively impacted. “We are not able to continue to focus through the exercise session because we’re tired from focusing so intensely prior to the workout,” says Angie Fifer, Health - Injuries.
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In one of the studies reviewed, researchers had athletes complete two workouts: In one, subjects watched a 90-minute documentary that didn’t cause mental strain, and then cycled at high intensity until exhaustion. In the other, subjects worked on a computer task that required intense concentration for 90 minutes, then performed the same high-intensity cycling until exhaustion.
When the athletes’ performances were analyzed, experts discovered that while physical measurements—such as heart rate, blood lactate, and oxygen consumption—weren’t affected by the mentally-fatiguing task, psychological ones like perceived effort were. The latter workouts felt nearly 10 percent tougher, which resulted in an impaired performance, says study author Jeroen Van Cutsem, Ph.D.
While he’s not able to say definitively what’s happening, Van Cutsem theorizes that this increased perception of effort could occur because when you’re mentally tired, your brain has to boost how much it talks to your muscles in order to perform at the same level. That’s known as a higher signaling rate, and it makes it feel like you have to work harder physically. Another theory is that your brain processes effort differently when you’re mentally drained, which could also make the workout seem more difficult.
It’s important to note, however, that mental fatigue isn’t the same thing as burnout—the latter is a chronic state of brain drain, one that’s triggered by things like a consistently high workload, job insecurity, or little control of the daily things happening around you, says Van Cutsem. Those things can all add up to emotional exhaustion and feelings of inadequacy, which can turn into long-term problems. What we’re talking about here is acute, and happens when your brain is tired from prolonged periods—typically 30 minutes to two hours—of demanding exertion.
“A tough day at work, having to work through a specific challenge or problem, or delivering a pitch or presentation can all cause mental fatigue,” says Fifer. “Basically, it’s anything that requires a significant amount of focus over an extended amount of time.”
Before you worry about whether or not your brain is too tired for a workout (which, ironically, will only tucker it out more), the upside is that not all workouts are impacted by mental fatigue. Van Cutsem says that the intensity is what matters. “It’s about endurance workouts versus all-out, maximum-effort ones,” he says. Short, all-out workouts (like HIIT intervals) don’t require a ton of cognitive processing, so it doesn’t really matter how tired your brain is. “The shorter and more maximal the task, the lower the impact of mental fatigue,” he says.
It’s kind of like doing something before your brain even figures out what’s happening: Busting out a 20-second high-intensity interval is mentally easier to push through than steeling your mind for a two-hour long run. So, if your workout doesn’t require a ton of thought—it’s more about physically powering through—then that can be the better option on days you’re feeling mentally exhausted.
There are also ways to combat mental fatigue throughout your day, adds Fifer. Her biggest tip: Structure your day with a break in between intense meetings or brainstorming sessions. “While we can power through and get more done, it’s better for us mentally to manage stress and take short breaks,” she explains. “The general rule of thumb is to focus intensely for 20 minutes with a five-minute break.”
On days when you’re just not feeling like your head’s in the game, consider tweaking your training schedule to do something that requires less thought processes. A shorter, casually paced run could be just what you need to decompress and recharge the batteries before your next batch of hard-effort miles. Van Cutsem says preliminary research even shows that doing so might improve your resistance to mental exhaustion, resulting in greater mental toughness for important events like race day.
Sadly, there is no simple test that can definitely say your brain is too tired for a long workout because, well, every brain is different. But Fifer says to keep an eye out for a drop in motivation—especially if it doesn’t disappear once you start sweating. “If you can’t get into a workout, that indicates that you may need to slow it down,” she explains. Listen to your perceived effort level that day, and be OK with mixing up your training schedule as needed.
How to Prevent Fatigue
You can’t always avoid mental fatigue, but there are tricks that can make your run feel like less of a slog. Here’s what the pros recommend.
Scroll through social media or turn on the news, and youll see widespread. So long as you get a good night’s sleep the night before, lacing up in the morning is one of the easiest ways to make sure you’re feeling mentally fresh, says Fifer.
Join Runners World+ for unlimited access to the best training tips for runners. A 2017 study found that rinsing your mouth with a caffeine-containing drink before a workout resulted in a higher resistance to mental fatigue and the ability to keep up cognitive performance. Be it Sales & Deals or a cold brew, protests against systemic racism and police brutality in America.
A Part of Hearst Digital Media. You don’t have to nix it altogether, but avoid scrolling right before you run, suggests Amy Saltzman, M.D., author of From Runners World for Icy Hot. “Many people think scrolling through social media or spending time with family or friends will be relaxing, yet when they really check in they realize that these activities are draining and often leave them feeling irritated,” she explains.
How Muscle Fatigue Can Actually Fry Your Brain. Running at night can get rid of the day’s stress, but if you jump right from a project into a sweat session, your workout is likely to suffer. Instead, use your commute time to decompress and shift gears. Saltzman suggests mindful meditation. “Deliberately resting your attention in the present moment, on the rhythm of the breath or the sensations in the body, can provide a mental recharge during the course of the day and while training and competing.”
Take a deep breath. If your commute pulls double-duty as your workout, Fifer says taking a few minutes for deep breathing exercises can still help recharge your mental batteries. Make them a part of your warm-up before running out the door.
Samantha Lefave is an experienced writer and editor covering fitness, health, and travel. She regularly interviews pro athletes, elite trainers, and nutrition experts at the top of their field; her work has appeared in Runner's World, Bicycling, Outside, Men's Health and Women's Health, Cosmopolitan, Glamour, and more.
