What should you believe after a race, your official time or your watch?

You just finished a 5K, but your watch says you ran 3.22 miles, not 3.1. Was it really a 5K? Or maybe you finished your half marathon with a race time of 2:02:10, but your watch says 1:59:59. Can you tell your friends you ran a half marathon in under two hours? I’ll give my verdict on those scenarios, but first we need to talk about how race distances are measured and timed.

What is the difference between start time, chip time and time?

Before we go any further, I want to make sure we are all clear about the different ways to measure your time in a race.

Weapon time

Weapon time is the time from the start of the race (often signalled by a starting pistol, hence “gun”) to crossing the finish line. This is sometimes also called time.

If you try actually win When you attend the race, you may need to worry about the start time. Sometimes the rules state that the person who crosses the finish line first wins the race, regardless of when they crossed the start line. Generally, if you are an elite athlete looking to win a major race, you will make arrangements with the race organizer to be at the actual start line when the race starts, so that the start time accurately reflects how long it took you to complete the race.

But for the rest of us, start time doesn’t matter at all. If you’re the 5,000th person behind the start line in a major marathon, it’ll take a few minutes from the starting gun to actually arriving at the start line.

Most of us can just forget the start time. It’s not for us. The exception is if you’re in a very small local race that doesn’t use chip timing or where there’s only a mat at the finish line (no mat at the start).

Chip time

Chip timesometimes also called Net timeis the time from which You personally cross the starting line until You personally cross the finish line.

This is due to exactly the scenario I described above, which is that there is a crowd at the start line. If you are running a big city marathon, you may have to wait 10 minutes or more and then slowly sneak through the crowd before you can cross the start line. In this case, your marathon might have a start time of 4:40:00 and a chip time of 4:30:00.

The “chip” in the name refers to a computer chip that is usually embedded in your race bib (the number you pin to your shirt). The timing system registers a data point when you cross a timing mat on the ground. There is a timing mat at the start and another at the end of the race. (In longer races such as marathons and half marathons, there may also be timing mats at some checkpoints along the course, such as the halfway point.)

Playback time

Playback time is the name I use here for the time you see on your watch or in your running app after the fact. If you start and stop the timer exactly when you cross the start and finish lines, and never pause it in between, it should theoretically match the chip time. But I’ll discuss some problems with this assumption below.

Chip time is what matters

As I mentioned above, the start time is only important if you are trying to win an award in a race where the start time is used for awards, or if you try to qualify for the Olympic Games.

Use the chip time whenever you tell someone what you ran or when you track your personal bests (PBs). (Only use the clock time if you ran a race without a chip time, and even then be sure to use your actual total time between the start and finish lines. In this case, do not trust the clock any more than the chip time, but use it only to estimate a missing chip time.)

Playback time should would be the same time as the chip time if you had started and stopped your watch at the start and finish line. But this is often not the case. Some reasons why your time could be wrong:

• Your watch pauses automatically. This is a handy setting for training runs when you frequently stop for a drink or to wait to cross a road. Your watch will pause your run when you stop and resume recording when you start moving again. But during a race, stops aren’t free! If you stop to spend two minutes on a portable toilet, that’s still part of your race time.

• Your app (e.g. Strava) may report a “movement time”. Same idea as above, but it also happens if your watch has everything recorded. For example, I remember stopping to tie my shoes on a longer run I did earlier this week. Strava shows a time of 1:17:02 for that run. But if I scroll down through the numbers displayed, I can also see an elapsed time of 1:17:28. I estimate it took me 26 seconds to tie my shoes.

To Stravayou can first view your elapsed time by selecting “Edit Activity” and then changing “Run Type” to “Race.” If I do that on my run yesterday where I had to tie my shoes, the elapsed time with the extra 26 seconds is shown on that Strava activity.

There’s another reason why your official race result might not make sense, even if it’s a chip time and it matches the total time shown on your watch: Every now and then, a race organizer screws up.

I once ran a 2k (1.2 mile) race and expected a finish time between nine and ten minutes. My watch showed a number in that range, but I knew it was probably off by a few seconds. When I checked the official results shortly after crossing the finish line, I had a time that was about three minutes longer than expected! And in this case, I had started near the start line (it was a small, local race), so I couldn’t blame a time difference between the pistol and the chip. It turned out that the timing service accidentally added three minutes too everyone’s times. They caught the error pretty quickly, though, and my official time was soon updated to 9:29. (I got an age group medal that day and wrote my time on the back, which is why I still remember it all these years later.)

So if your official race result Away If you are not participating, you should speak to the race organizer. There may be an error that affects everyone, or there may only be one start time and no chip time.

Your watch measures more than the actual race distance

There is another consideration: not only the Time on your watch, but the distanceYou may find that your watch time is only a few seconds off from your chip time, but the gap seems wrong – usually too large.

The first thing to do is to check whether the race track is certified. (Most are certified.) The process of Certification of a race track ensures that the course is the right length. And that distance is almost guaranteed to be shorter than the distance most runners actually run. So yes, you’ll probably run a bit longer than 5K in a 5K (3.1 mi) race!

You can read the USATF course certification guidelines HereThis part is particularly interesting: “A race course is defined by the shortest possible route that a runner can take without being disqualified. However, a particular runner may take a different route…[t]The actual route of a runner is irrelevant. The shortest possible route is a reasonably well-defined and unambiguous route that ensures that all runners at least the specified race distance.” (Emphasis theirs.)

How do you find the shortest route? “You can imagine the shortest route as a string stretched taut along the route so that it passes within 30 cm (one foot) of all corners, straight through S-curves, and diagonally between corners when crossing a road. You should measure the route along the same route as this hypothetical string.” In addition, a correction factor of 0.1% is added to the measured distance to ensure “that your route not Be brief, even if you make small mistakes in taking the shortest possible route.”

The only case where your smartwatch’s distance should make you doubt the distance measurement is if your watch thinks you have covered a distance shorter distance than the stated length of the race. If this happens, check your map to see if the GPS route matches the route you actually ran. If your GPS accuracy is poor, your watch (or phone) may draw a line that cuts off a corner that you didn’t actually cut.

If your map looks correct but your distance is still short, check with other runners to see if they have also completed a short distance. Errors in route measurement or signage are rare, but they do happen! The San Francisco Marathon accidentally cut half a mile from its half marathon course this yearIf you think your race track is too short, contact the race organizer.

What counts as my personal best?

Your personal best, or PB, can be anything you desire in your heart, but if you want to brag about your times or compare them to other runners, you should be talking about chip time.

This is where the distance issue comes in. Maybe you completed your first 5K in a chip time of 30:03, but your watch congratulated you on a 5K personal best of 28:59. What’s going on? Check the distance, and you may see that your total race distance was 3.22 miles, with 28:59 being the time it took you to reach 3.1 miles (at this point, the finish line was in sight, but you weren’t done racing yet).

That is why we differentiate Race PBs out of Training PBs. The timing of the race track is more accurate and the certified distance is more accurate than that of your GPS, although the actual distance, the You personally The race may be slightly longer than the certified distance. People tend to run personal bests in races because that’s when you’re best prepared for a big effort and the crowds are cheering you on. But because the distance may be longer than stated, running a “5K race” in a certain time is a greater achievement than running exactly five kilometers in that time.

So when another runner asks for your 5K time, they mean a race. You can proudly and accurately state your chip time – in our example, 30:03. But you could also add, “My best training PB for this distance is 28:59, so I know I’ll officially break the 30-minute mark soon.” You will. I believe in you.