How Marathon Race Timing Works

Imagine this scene: You've completed months upon months of training and you're about to embark upon your marathon quest. The "Star Spangled Banner" has been sung, and a nervous tension hangs in the air. Crack! The starter's pistol sounds and … you wait and wait and shuffle a few steps and wait some more. That's what tends to happen to mid-pack runners in the bigger marathons. They get stuck in a human traffic jam that doesn't even begin to clear until they cross the starting line, which is well after the race clock has begun ticking away.

When tens of thousands of runners congregate -- as is the case for premiere events like the Chicago and New York City marathons -- a runner may not cross the starting line for as many as 22 minutes after the race begins [source: Sinha]. Those minutes are valuable to a runner who's trying to beat a friend's time , qualify for an exclusive race like the Boston Marathon or simply reach a pre-determined goal. That's why most marathon race results indicate a runner's "gun time" (the time from when the actual race clock began) and her "chip time" or "actual time" (the time from when she crossed the starting line). The chip or actual time is the true, net result.

For years, race organizers depended on numbered race bibs with pull-off tags to record marathon times and preserve the correct order of finish. The runner would cross the finish line, her race number and finish time would be written down and a pull-off tag at the bottom of her race bib (which included important information like name and age) would be ripped off and put on a spindle in the order of finish [source: Mitchell]. As marathons became a bit larger, finishers were hustled into finishing chutes until volunteers could tear off the tags from the athlete's shirt-front. But how to offset the difference between Runner A and Runner B's start times?

Enter the timing chip and subsequent marathon tracking technologies.

Running is, in many ways, the simplest of sports. It doesn't truly require any equipment other than what you're born with -- heart, lungs, legs and feet. But technology made a big impact on race organizers when the marathon timing chip was introduced in the 1990s. Suddenly, they were able to track runners from the second they crossed the start line to when they reached the 5-kilometer point, to halfway through the event and the all-important finish line.

Timing chips are typically encased in a hard plastic ring and given to each runner in their race packet prior to the event. The morning of the race, marathoners tie the ring into their shoelaces. Meantime, antennas sheathed in wide, rubber mats are positioned along the course. When the marathoner steps on the rubber mat across the starting line, his individual chip is electronically recognized by the timing system, and his time begins [source: Sinha]. Likewise, any time he or she steps on one of the specialty mats along the course, a computer records the accumulated time to that point in the race.

Chip timing revolutionized marathon timing, but its drawbacks were recognized as well. While it offered accuracy and simplicity, chip timing was labeled by some as too expensive. Each timing chip ring had to be removed from the shoelaces of weary athletes at the finish line by race volunteers and returned to the given company that was timing the race. If an athlete happened to stumble past a volunteer and later discarded the chip, he would be billed as much as $30.

In 2007, organizers of the Philadelphia Marathon and the Las Vegas Marathon opted to use the services of a business offering a disposable microchip technology. The chip was actually part of the runner's race bib. Each runner simply tore the adhesive-backed label from the bib and attached it to his shoelaces. After the race, the chip was simply discarded. The system worked well until the Honolulu Marathon in December 2007. Severe weather caused the system to malfunction, resulting in inaccurate finish times and several thousand runners not having their finish recorded by the system at all. Houston Marathon officials who were set to use the disposable microchips for their race in January had a change of heart and reverted to the older technology [source: MacInnis].

As of 2010, both the standard chip timing system and the relatively new disposable chip system were available and in use in notable races [sources: MYLAPS, ChronoTrack Systems].