How Exercise Shapes You, Far Beyond the Gym, by Bradley Stulberg.

Ask anyone whose day regularly includes a hard bike ride, sprints in the pool, a complex problem on the climbing wall, or a progressive powerlifting circuit, and they’ll likely tell you the same: A difficult conversation just doesn’t seem so difficult anymore. A tight deadline not so intimidating. Relationship problems not so problematic. …

While the traditional benefits of vigorous exercise — like prevention and treatment of diabetes, heart disease, stroke, hypertension, and osteoporosis — are well known and often reported, the most powerful benefit might be the lesson that my coach imparted to me: In a world where comfort is king, arduous physical activity provides a rare opportunity to practice suffering.