David Jaewon Oh
Most runners run too hard. We log the majority of our miles at moderate- and high-intensity speeds, barely deigning to hit the low-intensity paces that are so essential to building an aerobic base. Yes, running slow takes longer. Yes, you may not feel quite as accomplished postrun. But go too hard too often and instead of seeing performance benefits, you’re more likely to burn out.
Take the case of two groups of recreational runners who were tested in a 2013
study published in the
International Journal of Sports Physiology and Performance: One group spent 77 percent of their time doing low-intensity workouts, 3 percent doing moderate-intensity workouts, and 20 percent doing high-intensity workouts, a method called polarized training. The other group spent 46 percent of their time doing low-intensity workouts, 35 percent doing moderate-intensity workouts, and 19 percent doing high-intensity workouts. After 10 weeks, both groups improved their 10K times, but the polarized training group improved by nearly double the amount of time, shaving about 41 seconds off the total time.