Um, we woulda known this. If we ever bothered to, you know, think hard:
SCIENCE PROVES WHAT WE ALREADY SUSPECTED. HARD THINKING REALLY DOES WEAR OUT OUR BODIES, THOUGH WE CAN’T ACTUALLY EXPLAIN WHY
by Mark Wilson
Some days, you leave work at 5 p.m. ready to pick up the kids, make a three-course meal, build a birdhouse, and hit the gym. Others, you walk in the door and collapse on the couch, begging for the sweet release of reality TV to soothe your inexplicably sore body along with a delivery pizza to fuel you up for a particularly intense eight hours of sleep.
Both days your “work” was just sitting at your desk, but one left you far more physically exhausted. Why? Well, were you thinking harder on pizza day?
Because as PopSci points out, a study headed by Samuele Marcora, a University of Kent Professor of Exercise Physiology, has proven that thinking hard really can leave your body exhausted. Researchers gave subjects one of two 90-minute tasks–one playing a mentally engaging computer test, and one watching documentaries on trains and Ferraris. Then they were asked to hop on a bike. In almost all cases, the documentary watchers were able to peddle longer than those who’d been tested by a computer for an hour and a half. And in a twist of science, heart rate, respiration, and blood glucose levels were consistent between the two groups. (Apparently, there’s no known metric for force of will.)