When elite runners were tasked with thinking aloud during an eight-mile run, 32 percent of them thought about how painful running was. "Hill, you're a bitch," was one runner's spoken thought, according to a study published in the International Journal of Sport and Exercise Psychology in June. Another 40 percent thought about their time and pacing ("Hips forward, my stride a little bit wider than normal; a nice heel toe."), and 28 percent thought about their environment ("These trees are so cool in the wind.").