Tag: foot strike

Press Release:

New research from La Trobe University suggests there is no evidence that changing a runner’s strike pattern will help prevent injuries or give them a speed boost.

In a bid to avoid shin splints, sore knees and other injuries, many runners have adopted a toe-to-heel trend, running on the balls of their feet. This is often encouraged by coaches and health professionals.

However, in research out this week in Sports Medicine, La Trobe injury researcher and physiotherapist Dr Christian Barton found there is no evidence to suggest running on the front of your feet reduces injury risk or improves performance.

“We analysed 53 studies which looked at the impact of forefoot, rearfoot and flatfoot running patterns on injury, running economy and running biomechanics,” senior author of the study, Dr Barton said

“Our comprehensive review suggests that telling someone to run on the ball of their foot instead of their heel may make them less efficient, at least in the short term. Additionally, there is no evidence either way on whether running on the balls of your feet reduces injury.”

Dr Barton said switching your running style shifts the body’s loads but doesn’t make them disappear.

“Running toe-heel might help injuries at the knee, where loads are reduced. However, it may cause injuries to the feet and ankle, where loads are increased,” Dr Barton said.

“Put simply, when it comes to running style: If it ain’t broke, don’t fix it.”

Press Release:

ANN ARBOR–Contrary to long-standing popular belief, running at a prescribed, one-size-fits-all “optimal” cadence doesn’t play as big a role in speed and efficiency as once thought.

Since the 1980s, when running coach Jack Daniels noted that the step rate for runners in the 1984 Olympics was about 180 per minute, it’s been widely touted as a means to reduce injury or improve speed, said Geoff Burns, an elite marathoner and University of Michigan doctoral student in kinesiology.

“It’s one of the few biomechanical measures we have that is a gross system-level output for running,” he said.

To find out what determines cadence and how much cadence really matters, Burns had the top 20 elite male and female runners record their cadence during the 100K International Association of Ultrarunners World Championship in 2016.

While the average number of steps per minute was 182, the number of steps per minute per mile varied enormously by individual.

“Some ran at 160 steps per minutes and others ran at 210 steps per minute, and it wasn’t related at all to how good they were or how fast they were,” Burns said. “Height influenced it a little bit, but even people who were the same height had an enormous amount of variability.”

The main takeaway for runners is that cadence is highly individual, and your body knows what’s optimal, said Burns, a third-year Ph.D. student in Professor Ronald Zernicke’s lab. This means runners shouldn’t necessarily try to manipulate cadence to reach the 180 steps, but rather, monitor cadence as their running progresses.

“It’s a barometer and not a governor,” he said. “There’s no magical number that’s dogmatically right for everybody.”

For years, many coaches and practitioners thought that cadence should remain constant as speed increases, which required longer steps. Burns says longer steps takes more energy, and his study found that cadence naturally increased four to five steps per minute per mile as runners ran faster.

Other findings surprised Burns, as well. First, step cadence was preserved through the race, even during the torturous “ultra shuffle” near the end–when racers shuffle across the finish line, barely lifting their feet.

Burns assumed that exhausted runners would take shorter, choppier steps. But surprisingly, when researchers controlled for speed, cadence stayed constant.

Another unexpected finding is that by the end of a race, cadence varied much less per minute, as if the fatigued runner’s body had locked into an optimal steps-per-minute turnover. It’s unclear why, Burns said, but this deserves further study.

An ultramarathon is anything longer than a traditional marathon of 26 miles. As a semi-pro ultramarathoner, Burns spends about two hours a day running and another two hours a day on conditioning–in addition to his doctoral work.

“It’s a really unique symbiotic relationship,” he said. “My running informs my research and helps me not just ask novel questions and gain insight and perspective into the craft, but also helps me refine how I prepare for races.”

Burns’ research appears in the February issue of Applied Physiology.

Press release:

USA Track and Field consultant Iain Hunter and U.S. Olympian Jared Ward have a message for runners: Don’t mess with your stride.

A new study by the duo of BYU professors finds the stride length people naturally choose is the best for them, whether they are experienced or inexperienced runners. That means whatever shape you are in — marathon warrior or weekend jogger — stick with what you’re doing.

“Don’t worry about changing your stride length,” said Hunter, a professor of exercise science at BYU. “You should just leave it alone or you’re going to use more energy in the end.”

The study, published in the International Journal of Exercise Science, measured the energy use of 33 runners while carrying out various strides during a 20-minute run. Of those runners, 19 were experienced runners (meaning they averaged at least 20 miles a week) while 14 were inexperienced runners (people who have never run more than 5 miles in a week).

During their runs participants used five different stride lengths: their natural stride, and then strides of plus and minus 8 and 16 percent of their normal stride. Subjects maintained the adjusted strides thanks to the assistance of a computer-based metronome, which beeped each time their foot should’ve hit the treadmill. Meanwhile, researchers measured the energy output of the runners with masks that recorded the amount of oxygen used.

The results found both the experienced and the inexperienced runners were most efficient when they were using their preferred stride. Thus, athletes and coaches don’t need to alter a runner’s stride length when economy is the main concern.

“Just let it happen; it doesn’t need to be coached,” Hunter said. “Your body is your best coach for stride length.”

Hunter and Ward would know — both are experienced runners and both have trained and researched high-level distance runners for years. Ward, of course, finished 6th in the marathon at the 2016 Olympics and recently finished in the top 10 of the 2017 Boston Marathon.

Ward, an adjunct faculty in the BYU statistics department, said the takeaway is similar to that of elite runners: Be very careful if you’re trying to alter your stride if efficiency is your main concern.

“Many people are advocating for various ‘optimal’ running forms, but this study shows even novice runners shouldn’t try to run any different than their body naturally does,” he said. “Enjoy running and worry less about what things look like.”

Hunter’s expertise has led him to carry out biomechanical analyses for USA Track and Field for the past 14 years. He is headed to London this August with Team USA for the World Championships, where he will help film and analyze U.S. athletes during competitions.

Kelly Lee, a BYU undergraduate, and James Tracy, a former BYU steeplechase athlete and a current grad student, were also coauthors on the paper.