New Runners Don't Self-Select Best Stride Rate

In study, increasing stride frequency leads to more economical running.

Wednesday, May 1, 2013, 12:00 am

Running is a natural activity, but that doesn't mean we all automatically run in the most efficient way. Consider, for example, a study published in the European Journal of Sports Science. It found that, when new runners were asked to run at whatever stride rate they wanted, none picked the most economical frequency. But long-time runners shouldn't necessarily get smug: In the study, runners with an average 10-K PR of 34:53 also didn't self-select the most economical stride rate.

For the study, Dutch researchers gathered 10 young (age 23) men who were active but not runners, and the above-mentioned 10 experienced runners. They measured the subjects' ventilatory threshold, which for experienced runners is usually about the pace that can be sustained for approximately an hour. (For the experienced runners in this study, for example, it occurred at just over 6:00 per mile pace.) The researchers then calculated what pace 80% of ventilatory threshold was for each participant. In running terms, this is a relaxed, conversational pace (around 7:40 per mile for the experienced runners in this study).

Next, the participants ran on a treadmill at their 80%-of-ventilatory-threshold pace. They were first told to run at whatever stride rate they wanted. Then, while maintaining the same speed, they were instructed to increase or decrease their stride rate to match a metronome. The metronome was adjusted so that the runners did 2-minute bouts at a stride rate 6%, 12% and 18% greater than their self-selected stride rate, and also 6%, 12% and 18% less than their self-selected stride rate.

Throughout, the researchers measured the runners' oxygen consumption and heart rate.

The new runners "ran with a stride frequency which was about 8% lower than optimal stride frequency," the researchers wrote.

By that they mean that, at a higher number of steps per minute, the new runners consumed less oxygen at the same pace. All ten of the new runners self-selected a stride rate that was too low, the researchers say. Their average stride rate was 77.8 strides per minute, or 155.6 steps per minute; their optimal at that pace, the researchers says, was 84.9 strides per minute, or 169.8 steps per minute.

Seven of the 10 experienced runners self-selected a too-low stride rate, the researchers say, but overall the group was within 3% of optimal, compared to the new runners being off by 8%.

Coaches have long noted that many new runners tend to take longer, fewer strides at a given pace than more experienced runners, and that when they get these runners to adopt a quicker turnover, the runners find their training easier. As the researchers note:

"Reductions [in oxygen consumption at a set pace] were substantial in some individuals, with gains of about 3-5% for some novice runners and potential improvements of about 1% for some trained runners. Although these reductions are relatively small, they probably relate to meaningful improvements of running performance and are easy to achieve."

For 18 of the 20 runners studied, their heart rate was lowest at the stride rate at which they consumed the least oxygen. Therefore, to see if you would benefit from a quicker stride rate, "it would be sufficient to measure heart rate while running at constant speed and changing stride frequency," the researchers wrote. "Since these are relatively easy measurements, they could be repeated on multiple occasions, which would increase the reliability of the advice for individual runners."



Tags: Running Form