Mental drain mid-workout could compromise your capacity, a new study finds
You're finally trying out that new spin studio, but halfway through class (while struggling to keep up with the moves your instructor is barking out), you're exhausted. What gives? Trying to tackle a physical and mental task at once takes a toll on our endurance, according to a recent study in Human Factors: The Journal of the Human Factors and Ergonomics Society.
Researchers from Texas A&M University found that people have more difficulty performing mental and physical tasks at the same time. In the study, people did physical exercises, like squeezing a handgrip as hard as they could for as long as they could, with or without simultaneously solving complicated math problems and performing counting tasks. When the mental load was added on, people's blood oxygen levels were higher in the prefrontal cortex—the brain region responsible for physical movement—than when they were just exercising alone. When you have to think and move at the same time, your brain has to divide resources which, in turn, might impact your physical endurance and fatigue you sooner. (Learn to Keep Going and Going: How to Increase Endurance.)
And it's not just endurance—studies show mental fatigue can affect your speed, although in different ways. A recent study from the University of Florida found that light Multitasking Can Actually Make You Quicker on a Stationary Bike. But the improvement in speed dropped off once the task became too mentally taxing. The good news: The more you go to class, the more your brain will get used to the exercise. (Check out these Fat-Burning Spin Workouts to Help You Build Endurance.)
And mental distraction isn't all bad. Distracting thoughts can be helpful for newbies who need to build motivation and exercise habits more than they need stamina and endurance, says Sari Shepphird, Ph.D., a sports psychologist and contributing author to Sports Leadership: A Concise Reference Guide. "For beginning exercisers, it's better to distract themselves from thoughts about anxiety, comparisons, or fear." But if you're a seasoned sweater, what should you be focusing on? Shepphird recommends paying attention to your heart rate, muscle tension, and breathing rate. Use that information to make minor adjustments to your gait, stance, or pace. And, she adds, that focus will help channel your brain's resources into your physical performance.