Walk, Don't Run
How hiking can speed up your trail runs
Do you think walking is anathema to trail running? You're plain wrong. ...
Photo by Kevin Steele
Do you think walking is anathema to trail running? You're plain wrong. It's all a matter of degrees. Even the world's best trail runners walk when the terrain, slope and distance dictate they do so.
And, we're not just talking about ultramarathons. For instance, during the 12-kilometer 2010 World Mountain Running Championships, Max King, the second American on the United States' silver-medal-winning team, "didn't walk much, but there was a steep two-mile section of which I walked probably 10 percent. I never like to [walk], but sometimes it just makes sense."
As humans, we have two primary forms of bipedal locomotion: running and walking. As a general rule, walking is more energy efficient at slower speeds while running is more efficient at faster speeds. This principle does not change when we begin charging up a hill. The constant tug of gravity's pull does, however, reduce the speed at which the transition from running to walking occurs, for two reasons.
First, there's the physics. Running is essentially a series of bounds separated by a moment of suspension. During the suspension phase, gravity accelerates us downward, which results in a "tall" parabolic arc with an increased vertical component. We use significant energy to launch ourselves into the suspension phase against the pull of gravity.
On the other hand, walking lacks the moment of suspension. Instead, we travel in a series of "flatter" circular arcs. When we run up a hill, we need to exaggerate the height of flight phase, while there is no flight phase to exaggerate when walking uphill. Ultrarunner Krissy Moehl succinctly crystallized this concept, "Walking takes the bouncing out of your stride."
Second, as a hill's gradient increases, so will the effort required to run up it. In longer races, the effort needed to run a particular incline may exceed the average effort a runner will optimally expend during the race and, therefore, burn through fuel stores too fast. In shorter races, it might simply be impossible to continue running up a steep pitch.