Power meter showdown
Over the last few years, a new metric has caught the attention of tech-curious runners: running power. Power is already a common metric among cyclists, who use devices that measure how hard they’re cranking the pedals. In cycling, there’s a direct relationship between the power you apply to the pedals and how hard you’re working: cycling power is, in effect, a highly accurate real-time calorie counter, which makes it very useful for monitoring training and pacing yourself during workouts and races.
Running, by contrast, is more complicated than cycling. Your arms and legs move back and forth in relation to your body, you’re bouncing up and down and your tendons and ligaments are stretching and snapping back like elastics to store and return energy with each stride. As a result, there isn’t always a consistent relationship between how hard your feet are striking the ground and how hard you’re working, especially when you climb or descend hills.
Still, in the last few years, several companies have begun offering running power meters that, like their cycling equivalents, try to offer a real-time estimate of how hard you’re working, without the time lag that hampers other measures like heart rate. But how well do they actually live up to their promises? In the European Journal of Sport Science, a team of researchers from the University of Murcia, in Spain, put four current power meters (a Stryd footpod, RunScribe footpods, Garmin’s Running Power app and Polar’s watch-based power estimate) through a series of tests.
In the two most important tests, Stryd came out on top. It gave the most consistent measurements, varying on average by 4.3 per cent when the same run was repeated twice. In comparison, the other devices varied by between seven and 15 percent. When the running power measurement was compared to oxygen consumption, which is a lab-measured proxy for how much energy you’re burning, Stryd’s values were consistent within 6.5 per cent. The other devices deviated by between nine and 15 percent. The bottom line: the utility of running power is still up for debate, but if you want to experiment with it, Stryd currently has the best meter.