Though it is the most basic of all sports, running has always had a pretty high Geek factor, especially among its more serious adherents.   Whether it’s in shoe design, the latest moisture-wicking apparel, or the most sophisticated GPS or heart rate monitor, runners are always searching for that Holy Grail that might help get them from point A to point B even faster than before.

Over the years, the Los Angeles Marathon has ushered in a number of technological firsts for the sport.  In 1996, LA was the first major U.S. marathon to utilize a field-wide chip timing system. Then in 2009, LA became the first big city 26-miler to fully adopt social media outlets such as Facebook, YouTube, RSS, Flickr and Twitter.  Now again in 2012 L.A. will showcase another new technology. But this development, rather than being ancillary to the sport, is focused on directly on it. What’s more, it has the potential to unlock long hidden secret chambers that, once opened, could change the very nature of how runners train, avoid injury, while at the same time illuminate the competition for a television audience in a way never before possible.

This Sunday at the 27thHonda LA Marathon, wireless sensor technology will be utilized to monitor and analyze the stride characteristics of several runners, both elite and local, as they move from the start line at Dodger Stadium 26.2 miles to the finish line in Santa Monica.

Pegasus Sensors

Small motion-detecting sensors, weighing less than an ounce each, will be worn atop the shoe laces of the runners. Then, using a smartphone transmission, three distinct characteristics of their strides – Cadence, Ground Contact Time, and Kick Dynamic – will be uploaded to KTLA-TV which will then broadcast those metrics in real time via an on-screen dashboard for analysis and comparison.

“Through this technology, we can identify the changes in a runner’s stride dynamic over the course of the marathon,” explained Bill Kaiser, co-director of the UCLA Wireless Health Institute, and one of the inventors of the technology now licensed by Pegasus Sports Performance.“We can then analyze those changes to evaluate their efficiency as fatigue begins to take its toll, but which might yet be too subtle for the human eye, alone, to pick up.”


Cadence (strides per minute), Ground Contact Time, and Kick Dynamic (called distal leg lift) will be monitored on a continuous basis at a rate of 60-100Hz per second. These metrics will then be shown to the TV audience in real time on a graphic dashboard throughout the race – no different than how NASCAR illustrates the internal workings of their race cars on TV via dashboard displays.

Josh Cox Laces Up

Josh Laces up

“I’ve trained with the sensors several times, and competed in them once,” said Josh Cox, American 50K record holder who beta tested the sensors at last fall’s Rock `n’ Roll Los Angeles Half Marathon. “The advantages for the athlete are twofold. One, you can analyze the data post-race or post-workout, and fine tune your workouts according to what you’ve learned about your stride mechanics. But it’s a real eye-in-the-sky for the coach, who is able to coordinate and monitor an athlete’s stride characteristics during the workout itself. And while an athlete might have previously given his coach feedback like ‘maybe I went out a little too hard, but I felt okay on that last interval’, now the coach can just look at his smartphone and say, ‘Hey, your heart rate is up, your stride is beginning to change. You’re doing more harm than good. You’re done for the day’.”

Perhaps more impressive is the ability to actually monitor a workout in real-time off site. Say Meb Keflezighi was in Mammoth, California doing a tempo run, but his coach Bob Larsen was back home L.A. Bob could still monitor Meb’s workout in real time via his smartphone or computer as he watches Meb’s heart rate, cadence, ground contact time, kick dynamic, pronation, and supination 300 miles to the north. Then, with an escort alongside in a car or on a bike – as Meb so often has – coach Larsen could communicate his observations and instructions to Meb on the fly.

The idea for analyzing gait characteristics began years ago at the UCLA Wireless Health Institute where engineers and doctors working in tandem created smartphone transmitted wireless sensors for Parkinson’s Disease and stroke patients. By analyzing their abnormal gaits in real time, even beyond the hospital setting, the doctors could better adjust treatments and improve patient care. With the advances in miniaturization, that same sensor technology is now being brought to the other end of the health spectrum, athletic performance. And though the technology is applicable to just about any sport where motion analysis might prove critical, the initial application will be developed for the sport of running.

While in the past we have been able to monitor the pace of an athlete via splits, and then added heart rate monitoring to judge the effort related to that pace, it has always been the critical, but subjective, eye of the coach which has been the final arbiter of how to gauge an athlete’s training.  Training was like flying a bi-plane by the seat of your pants, a matter feel.  Now, with this new wireless technology, it’s as if we’ve landed in the cockpit of a modern jet fighter with objective hard data immediately available to help coaches break down the components of the mechanics that go into creating that effort.

“This gets into the whole Quality versus Quantity debate,” says Mammoth Track Club coach Terrence Mahon, who has tested the Pegasus sensors on his middle-distance stars Morgan Uceny and Anna Pierce during track interval sessions at the Olympic Training Center in Chula Vista, California.  “There has always been a question of how much quality training can an athlete do before it starts to compromise their mechanics or overload their system.  And what’s the magic number of miles to run per week? All of that has always been matter of hypothesis.  But these sensors answer those hidden questions.  Now you know exactly where that line is.”

The first stride characteristic that the sensors reveal is simple Cadence, or strides per minute. Testing has shown that 90-95 strides/minute is optimal. The second characteristic is Ground Contact Time (GCT), which sounds exactly like what it is, how long is the foot in contact with the ground through each stride cycle. GCT ranges up to 0.3 seconds per stride. Through this metric you can determine if energy is being lost as the GCT increases per foot-strike. And together, cadence and ground contact time can inform us who is using more energy per stride to remain at a given pace. Finally, we can examine the Kick Dynamic, or how far off the ground the trail leg comes on each stride. Reduction in back-kick height has been shown to be one of the earliest indicators of fatigue.

Another beta test of the wireless sensor system was conducted at last December’s Honolulu Marathon for a live radio broadcast. There three Kenyan runners wore the equipment, including seven-time Honolulu champion Jimmy Muindi and debuting marathoner Josphat Boit, a two-time NCAA track champion out of the University of Arkansas.


Though Jimmy and Josphat were running together in the lead pack, I could see on my smartphone readouts in the pace vehicle that after half-way Jimmy began to exhibit a declining cadence along with an increasing ground contact time compared to Josphat.  I could tell that Jimmy was losing more force per stride in GCT than Josphat, while his back-kick was beginning to lessen, as well. Therefore, all other things being equal, I suggested on-air that Muindi would likely fall off pace before his less experienced compatriot.


And true enough, not long afterwards, before any hard surges were made, or before I could detect any noticeable corruption in Muindi’s form, he went out the back. There was still the chance that Boit might falter late, being this was his debut marathon, but in fact his metrics held up remarkably well, and he went on to finish third in 2:15:40, an excellent time for the heat and humidity of Honolulu. Muindi finished sixth. The technology proved to be predictive of outcome!

“This in-race data will give the television viewers a unique perspective,” believes Josh Cox, who broadcasts marathons with me for Universal Sports. “It will put them right inside the workings of the lead pack. We commentators usually look for a change in facial expressions, or a slight elevation in arm carriage, or sway, or the beginnings of the rubber-band effect. But before any of that is apparent, we would see the decrease in cadence, the increase in ground contact time, and the reduction in back-kick elevation, any or all of which would be a precursor to the other visual cues we normally look for.

“But more importantly, this technology will allow runners and their coaches, of all levels, to fine tune their training, while being able to avoid injuries because they’ll be able to monitor the forces that might lead to those injuries before they happen.  It’s unlike anything we’ve ever had in running before.”

Training Run Data

This Sunday morning in Los Angeles, Kenya’s Simon Njoroge, a 2:09 marathoner, and Ethiopia’s Belainish Gebre, who has a best of 2:26, will wear the Pegasus sensors in the L.A. Marathon.  Also, two L.A. Road Runners shooting for a 3:15 finishing time will wear the technology, as well, David Mena and Susan Mitchell. Njoroge and Gebre tested the equipment Thursday during a training run in Griffith Park.    

KTLA-TV coverage will begin Sunday at 6 a.m. Pacific, and goes to 11 a.m. The elite women’s start will be around 7:10 a.m., with the elite men and the citizen racers taking off in hot pursuit 17:31 later. 17:31 is this year’s L.A. Gender Challenge differential, the amount of time the men will have to make up against the professional women to decide who wins the $100,000 bonus which goes to the first runner of either gender to cross the finish line in Santa Monica. The show will re-broadcast at noon Pacific on Universal Sports. Olympians Ed Eyestone and Julie Benson will join me along with KTLA sports anchor Derrin Horton on the call.

Pegasus Sports Performance CEO Bill Shea, an interventional radiologist by training, but a marathoner and Ironman endurance athlete by inclination, said, “We are excited to be working with the Honda LA Marathon and will seek to roll out this technology to other races in the near future.”

From my media perspective, the hope is that this new wireless sensor technology will enhance people’s understanding of the mechanics and efficiencies of an elite (or regular) runner’s stride, and thereby increase the intrigue of running broadcasts as viewers get hooked into the dashboard readouts and potential consequences. The eventual goal would be to equip the entire field with these sensors so that any friend or family member could go on-line and track his or her favorite runner’s progress and efficiencies.

When non-running people learn that I broadcast running events, they invariably ask, “Well, what do you say? They are only running.”

Normally, I quip, “What do baseball announcers say? They’re just standing there.”

Well, maybe now I will be better able to explain.



  1. Fascinating stuff! I had no idea analytical/measurement technologies had progressed so far. Their predictive abilities seem very convincing. No doubt they will also highlight the huge differences between the form of elite runners and joggers.
    I wonder how often predictions based on these measurements will be wrong, pointing to the “mental” aspect of competing in which an athlete with physical difficulties beats someone who is in better physical shape by sheer force of will. However, most elite athletes are also extremely tough mentally so the one in better physical shape may invariably win.

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