Another study, this one published in the European Journal of Applied Physiology, evaluated how exercise changes our physiological response to stress. Researchers at the Karlsruhe Institute of Technology, in Germany, divided students into two groups at the beginning of the semester and instructed half to run twice a week for 20 weeks. At the end of the 20 weeks, which coincided with a particularly stressful time for the students — exams — the researchers had the students wear heart-rate monitors to measure their heart-rate variability, which is a common indicator of physiological stress (the more variability, the less stress). As you might guess by now, the students who were enrolled in the running program showed significantly greater heart-rate variability. Their bodies literally were not as stressed during exams: They were more comfortable during a generally uncomfortable time.
What’s remarkable and encouraging about these studies is that the subjects weren’t exercising at heroic intensities or volumes. They were simply doing something that was physically challenging for them – going from no exercise to some exercise; one need not be an elite athlete or fitness nerd to reap the bulletproofing benefits of exercise.
Why does any of this matter? For one, articles that claim prioritizing big fitness goals is a waste of time (exhibit A: “Don’t Run a Marathon”) are downright wrong. But far more important than internet banter, perhaps a broader reframing of exercise is in order. Exercise isn’t just about helping out your health down the road, and it’s certainly not just about vanity. What you do in the gym (or on the roads, in the ocean, etc.) makes you a better, higher-performing person outside of it. The truth, cliché as it may sound, is this: When you develop physical fitness, you’re developing life fitness, too.
Brad Stulberg is a columnist for Outside Magazine, where he writes about health and the science of human performance. Follow him on Twitter @Bstulberg.