Posted: May 17, 2006

Running: Choosing Optimal Stride Length

From Run Strong by Kevin Beck

Every runner has a single maximally economical stride length for each speed. As mentioned earlier, running at faster speeds is accompanied by increasing stride length out of proportion to increasing frequency; therefore, a runner’s optimal stride length is different at each speed. At a given speed, however, if you run with a stride longer or shorter than optimal and adopt a slower or faster turnover, you will use more energy. If you study a group of experienced (but not elite) runners, you’ll find that many of them select stride lengths longer or shorter than their personal ideal, suggesting that many runners have some room to improve their running economy--and therefore their performance--by tinkering with their running stride. However, most experienced runners select a stride length that does not differ dramatically from the ideal, implying that overall running experience has something to do with the capacity to self-select an optimal stride length. When collegiate runners were studied across their college careers, researchers found that running stride lengths tended to decrease from their first year to their final year. This is in line with the findings that elite runners tend to have shorter strides than experienced, but less accomplished, runners.

This is all fine and good, but does it help an individual runner to optimize his or her stride? After all, some runners self-select stride lengths that are shorter than optimal. So what makes an optimal stride length? Well, it would be great to answer that question, but in fact, no one knows. As a general rule, taller runners with longer legs have longer optimal stride lengths (on average their optimal strides were 1.4 times their leg length while running seven-minute miles). On an individual basis, though, height and leg length are poor determinants of optimal stride length. In a study of 10 experienced runners, the subject with the shortest leg length had the longest self-selected and the longest optimal stride length. The runners, on average, chose stride lengths just four centimeters from optimal.

The problem is that without true predictors of what an optimal stride length is for an individual (and even a trained coach would probably have a hard time determining whether a runner was overstriding or understriding), there’s not much a runner can do except let his or her body adjust to an optimal stride through experience. It is also possible that the biomechanics researchers have been looking at this problem backward. Because stride length has to balance with stride frequency, or stride rate, to produce a given speed, and because each runner’s stride length varies widely across speeds while stride rate stays relatively constant (increasing slightly with increasing speeds), it is possible that runners choose a stride rate that is most efficient, regardless of the speed, and adjust stride length to obtain the desired speed.

Noted exercise physiologist and coach Jack Daniels places an emphasis on nudging new runners toward a faster stride rate. Daniels, who has helped more runners than his namesake has destroyed livers, selects 180 steps per minute as a target to reduce pounding forces associated with longer strides. Although beginning runners have a tendency to overstride somewhat, it is by no means certain that any runner can increase his or her running economy by arbitrarily choosing a different stride frequency; the same can be said for attempts to make oneself a forefoot-striker or a heel-striker. Both lead to fighting one’s most natural tendencies. One classic study of elite distance runners showed self-selected stride rates of 190 steps per minute at 5:24 mile pace. However, among less accomplished runners, efficiency was highest at frequencies slightly below 180 strides per minute, albeit at a much slower treadmill speed. Therefore, many runners can probably benefit from adopting a somewhat shorter stride length and faster turnover. There are, however, no magic numbers that can be applied to all runners looking to optimize their running form.

Posted with permission from Human Kinetics Publishers, Inc.

Comment on this story.

Subscribe to the Runner's Web Weekly Digest