The ongoing debate about which is better: running on a treadmill or running outside continues, in a recent story in the Los Angeles Times. Writer James S. Fell reports that, metabolically and biomechanically, the two activities have been found to be very similar. But, says Fell, running outdoors has a few mechanical training advantages, (which sound like disadvantages) such as wind resistance, downhills, turns and uneven surfaces. Treadmills, on the other hand, have one advantage: predictably pleasant weather. The Times cites a 2008 study, published in the journal Medicine & Science in Sports & Exercise, that found that runners adopt different running patterns when they’re on treadmills, such as landing a little more flat-footed, –an unsurprising revelation, considering that humans adapt their gait to run on snow, trails, synthetic tracks and sand. Now comes the clincher: an older, 2004 study, published in Psychology of Sport & Exercise, found that people who ran outside ran faster than those who ran on treadmills. Wait, there’s more. The same research, for which Duke University psychologists interviewed 60 runners who ran in different environments, found that the outdoor crowd had lower perceived exertion and the “highest levels of positive engagement, revitalization, tranquillity, and course satisfaction.” In other words, says Fell, people who run outside like it more and work harder without realizing it. Until now.