Understanding mental fatigue is the key to beating it, after all, it is what lies at the core of motivating yourself to hit the gym and push hard at every workout. The way the brain and body are interconnected suggests that the brain influences many markers of physical performance, including power, muscular endurance, reaction time, and processing speed.
It makes sense that mental fatigue would influence things like reaction time, processing speed, and focus but it can decrease endurance and strength performance. In a study conducted at Michigan Technological University, when participants were given mentally fatiguing questions while in the process of working out, strength performance decreased by 10-66 percent and endurance performance by 25 percent.
A 2017 review of 11 studies analyzing mental fatigue and physical performance confirmed those same results and the authors identified “higher than normal perceived exertion” as the culprit that was hurting endurance performance.
There are two potential explanations for why this happens:
1) The more tired you are mentally, the higher the signaling rate – how much the brain talks to the muscles in order for them to perform – making you feel like you have to work harder physically.
2) The brain processes effort differently when it is suffering from mental fatigue, which makes the workout seem more difficult than it actually is. For example, when the sensation of fatigue—burning legs, wheezing lungs—is amplified, the brain decides “this is enough,” and exhaustion sets in. You may be physiologically fine and your body may be capable of doing much more, yet you are mentally unable to go further.
There are two main models of mental fatigue: the central governor model and the psychobiological model.
The central governor model suggests that the brain regulates physical exertion, controlling output so you cannot threaten the body’s safe homeostasis. This is a top-down theory: The brain keeps you safe from harm but does it subconsciously.
In the psychobiological model, theorists observe that people exercise until they experience high levels of perceived effort, and they stop exercise without actually getting to physiological failure, often because they believe the task is physically impossible. This is done at a conscious level, as it relates to perception.
While the two models may differ in some aspects of how and why, they agree on the big picture:
Increased mental fatigue results in decreased athletic performance
Your ability to maintain self-control and actually work out, finish the workout, and train to physical exhaustion is a huge determining factor in your success.
According to researcher Roy Baumeister, willpower and self-control are limited. In 1998 he coined the term “ego depletion,” which suggests that self-control wanes over time which gave rise to the idea that willpower may be like a reservoir. Each act of self-control taps into the reservoir, which leaves less self-control available for other things that require it.
People have a hard time maintaining self-control over long stretches of time. We all know how many people join a gym or start an exercise program in January and find themselves skipping workouts by February. But it’s not just over weeks or months, you can drain your will power in the space of a day. Have you ever found yourself ordering an upsized burger and extra fries at 9pm when you’ve had a long, hard day – maybe there was cake at the office you turned down, or you politely declined a friend’s invite for a few beverages after work – your self-control has been exerted all day, starts to fail in the evening and there’s nothing left to counter temptation.
Now, while supplements like nootropics and ergogenics can improve physical performance, there are strategies you can use to get that extra push to fight mental fatigue and support your willpower without supplements that will help you stay on track.
Shorter, higher-intensity workouts don’t require as much mental energy as longer workouts. You can minimize the effect of mental fatigue on exercise performance by the type of exercise you do; for example, high-intensity interval training, which is high-intensity, low-duration activity.
You can also do things during the workday to keep mental fatigue in check. This is especially important if you plan to exercise after work. Having more mental energy available at the end of the day can improve your workout and may even make a difference in whether you make it to the gym at all.
Try taking short breaks throughout the day and that you focus intensely for 20 minutes with a 5-minute break, these brief mental breaks can help to slow mental fatigue. When you are taking your short break, try doing something different from your work. In other words, don’t take a break from working at a computer by looking at a smartphone. Try going for a short walk outside, or make yourself a cup of coffee and enjoy it away from your desk.
Make the new year one of commitment, self-care and achievement.