I sometimes run at a local high school track, and always assumed it was 400 meters, so I assumed a little over 4 laps was a mile. Last night I ran with my Timex GPS unit and it was telling me that less than 4 laps was a mile. Is 400 meters right? I only ask becuase the unit was telling me that I was going faster than normal, and when I was done, I looked up distance and it had said I was going farther than I thought. I was running in the inside lane.
Thanks,
The difference between 400 meters and 440 yards is way beyond the abillity of your GPS to track correctly around a circle. There are 2.54 centimeters per inch. Go from there and do the math. You will find that 400 meters is just under 437.5 yards.
Most modern tracks are 400 meters. The old 440 tracks will typically have a post in the center of the straightaway to indicate a Start/Finish line.
Outdoor running tracks typically come in two sizes:
400 metres
440 Yards ( quarter-mile)
A 400 metre(m) track is several metres short of 440 yards. Therefore if you run 4 laps of a 400m track, you will have run a little bit less than 1 mile. On a new 400m track that is laid out with all of the proper start lines on it, you will often see the start line for the 1 mile about 10 metres back down the track towards the start line for the 100m.
Not sure why the GPS unit was telling you what it was telling you. Some possibilities:
The track was not measured/built properly
The GPS unit was confused by the small circular route you were following on the track.
Could the discrepancy be based on the inherent inaccuracy of commercial gps units? I know that there is a bit of inaccuracy built in by the gov’t that gives coordinates within a few meters. Could this result in some inaccuracy in distances?
Craig
what you are referring to was called “selective availability”, and I believe they stopped adding the small % of error in 2001.
4x400m = 1600m
1 mile = 1609.344m
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Lots of good info on track distances and markings here: