This post is based on a blog post written by Eric Barker.

During my 7+ years of teaching Beastanetics, the one component of the program that has led to more anxiety than any other is the 400-meter run. Some of my students have been absolutely petrified that they couldn’t do it without stopping midway, or without vomiting (and a few have). But, over time, they’ve all been able to conquer the 400, and the amount of confidence that doing so has given them is astounding.

Researchers now believe that during vigorous aerobic exercise, the “anxiety-sensitive” person is forced to deal with many of the same symptoms that typically frighten him or her during periods of anxiety. These include a rapid heart rate, sweating, and rapid breathing. Over time, the “anxiety-sensitive” individual who continues to exercise vigorously can learn that these symptoms of arousal are usually not dangerous. And the fear that these symptoms trigger will gradually diminish in intensity (Salmon, 2001). Southwick and Charney, authors of Resilience: The Science of Mastering Life’s Greatest Challenges, found that the most resilient people had good exercise habits that kept their bodies, as well as their minds, strong.