When looking at a race's brochure, you will sometimes notice a line that references a certification number. It may be as short as "Certification #CO-06008-DP," or it may say something like "certified race course." Maybe it has both. But what does that mean?

As a runner, it means that you can run the race confident that your time is for an accurately-measured distance, and your time is useful to you when comparing your results to other races you have run (keeping in mind the variations in the terrain between the different courses). If you are training for a target race in the future, you can accurately assess your progress. If you have recently started running, you can see if you are improving. And if you are going to use your time as a qualifying time for another race, usually the course must be certified for your time to be accepted.

A certified course also means that the race director has been given descriptions of every mile-point (or kilometer, if appropriate), so if they place the mile markers in the correct location, you know your splits are for each mile; not a little longer for the first mile, a bit shorter for the second mile, accurate distance for the third mile, and so on. What good are splits if they are not for an accurate length? The certified course tells you that you should be able to trust your split times, in addition to your overall time.

Race directors can help keep runners satisfied with a certified course. How many times have we heard runners comment that they don't trust their times because they were so far off what they expected them to be? There is little chance of those runners returning to that race the following year.

How a Course Gets Certified
USA Track and Field has precise guidelines for how a course must be measured to become certified (see sidebar to understand why a car odometer is not even close to accurate enough, and neither is even the best GPS unit or cyclometer). The site has a list of approved measurers ( http://usatf.org/events/courses/measurers/) for the entire country.

Once a measurer has been selected, they will review the course with the course director and make sure there is sufficient allowance for modifying the distance to achieve the desired race distance. Each course has its own challenges for getting a precise distance, especially if the start and finish line must be in specific spots. When this is the case, it is best to have a turnaround spur that can be adjusted for precise course-length.

The measurement device is a bicycle with a Jones counter mounted on it. The Jones counter is a mechanical device that records 23 1/3 counts per revolution of the wheel. Therefore, the measurer must calibrate the bike before (and after) measuring each course (tire pressure affects the distance traveled with each revolution). Once the measurer has determined how many "clicks" the counter will have in each mile (18,000 - 19,000 is common), they ride the course at least twice, making sure both measurements are within .08% of each other (that's about 46 clicks, or 13 feet for a 5K course). If not, they ride again. During the ride, the measurer rides the shortest possible line that a runner may run on the course.

After measuring the course, the bike is calibrated again, and if there is a difference in clicks-per-mile, the number that results in the shortest course is used (the shortest course will still be as long as advertised). If that means going back out to the course to adjust the start, finish, or turnaround point, then it has to be done.

After riding , the measurer documents all his (or her) work, creates a detailed certification map, then submits all of that to the person that puts the USATF stamp of approval on the work and the course. If there are any questions or problems, the measurer has to explain it adequately, or go do it all again. But, in the end, the race director and the runners all will know that the course is the advertised length, making the times meaningful.

So, the next time you are looking for a race to run, check for an indication that the course is certified. You will know that the distance is accurate, and that the splits have been accurately identified.

Are Other Devices Accurate?
While modern measurement devices are wonderful to help us estimate our training runs and bike rides, they aren't always accurate.

A GPS unit is not accurate enough for a course to be USATF-certified. Even the best commercially-available GPS unit is only accurate to about 12 feet at any given time, and can be hundreds of feet off in accuracy. Most units will show you what their current accuracy is, and you can watch it vary from 12 feet to 350 feet or more. GPS units must have a clear view of at least three satellites to get a reading, and the more they can acquire, the more accurate they are. However, trees, buildings, and even your body can interrupt the signal, making it less accurate at any time.

Further, they only check their position periodically, not constantly. Some units check every second, some every 20 seconds. The user can sometimes set the unit to check at certain time or distance intervals, but if the unit has lost contact with the satellites, it can't tell where it is, so it misses that checkpoint. So, if you are running quickly, you may make a few turns while the unit doesn't have contact, so that section will be measured incorrectly.

Bicycle cyclometers are also not accurate enough for USATF because your tire pressure varies due to slow leaks or temperature variations. While you may take extreme care to calibrate it, you won't be riding in the same conditions every time. While you can calibrate to the tenth of a centimeter, the distance you have to ride to get a really accurate average is longer than most people have space to measure, and more revolutions than you can keep track of while riding a straight line.

Automobile odometers and personal pedometers are even less accurate. Cars for the tire-pressure reason along with the inherent inaccuracy of odometers, and pedometers due to the different lengths of each of your steps. Generally, for a 5K course, either of these methods may only get you to within 1/10 of a mile, many times even less accurate.

Duane Russell is a USATF-approved measurer, and has measured more than 15 race courses in the last year in Colorado, Arizona, and Idaho, from 5K to Marathon. You can contact him through his website at www.RaceMeasure.com or email at info@RaceMeasure.com.