Going off of GPS rather than laps for track TT...how is anyone this oblivious?

please stop wrote:

Anyone using a GPS watch on a track for any reason is an idiot. I don't care if you have to move into lane 3 to go around people. If you're that worried about running a few extra meters you're honestly just a pvssy.

Well, I only have one watch so I do use GPS on the track. However, I do not use the GPS readings. I go by the track markings and take my splits when I cross the line. The GPS part is just a way to roughly track my weekly mileage.

Coros has solved the problem of GPS accuracy on a track. It has a track mode and you can even set the lane you run in. I typically run in lane 7 and it gives me exactly the mile splits I expect if I set it to lane 7. I had a Garmin previously and it used to always come up 5-10% short. This is huge for me as I can run my intervals in outside lanes with less traffic and on a gentler curve.

A guy at my club ran 4.30 for the mile on the track and was crowing on Strava. Checked his map and he didn't even complete four laps, he was probably 50-60m short overall

big HONKING birds wrote:

I've noticed this from a few people I follow on Strava. They ran track in HS and college, yet finished their 5k TT when their watch hits exactly 3.1 (which, even if accurate, is equal to 4.98897 km), which means they ended up running roughly 12.2 laps rather than 12.5.

You're on a track, you know each lap is 400m, just count the laps lmao

Funny - I’ve run a 5k this way off track but I swapped my units to km for the very issue you point out with 3.1.

One time as an experiment I wore my Garmin for an 8000m run at the local track. I was the only person there, and I was in line 1 the entire time.

The Garmin registered 5.17 miles, which is a full 4% higher than the actual distance of 4.97 miles that I covered. That's pretty far off.

Norman "No Neck" Nunzio wrote:

bartholomew_maxwell wrote:

a GPS can be more accurate because it takes into account your full path of travel, shifting between lanes, etc, which makes your total distance run more or less than it would be if you had run in the same lane the entire run,

Not true. The GPS is not accurate enough to track distance on a track. The curves are very problematic for the GPS. It will always long on the track. This has nothing to do with weaving from lane to lane, though the GPS track may make it look like that is what was happening.

I've never had the GPS go long for me. In road races it does but never on the track.

Every once in a while my Garmin will get a track mile pretty close - maybe 5 meters short.

More often, I’m 1/2 to 2/3rds If the way down the home straight away when it clicks over to the mile. Sometimes more.

Fast Dad wrote:

My watch registers a longer distance on the track when running normal direction than opposite direction. I wear the watch on my lefthand which could account for a meter or two but it is off by several meters each lap which makes the difference about 25 meters in one direction as opposed to the other.

I wear my watch on my right hand and it makes sense that the watch distance is long-essentially you are in lane 2 (8 metres extra per lap-32 m for mile repeat). easy enough to know pace with any decent track, but it makes sense that watches have a falsely fast pace...hard to create curves with point to point lines between GPS "grabs" whereas the GPS is pretty useful for road workouts where it is way more accurate on straight running, and much fewer reference points such as lap markers...

Hardloper wrote:

This is from a run entirely in lane 1

https://i.imgur.com/bjF4qQP.png

Is that Nathan Hale HS track?

Not a Coros in track mode.

bartholomew_maxwell wrote:

a GPS can be more accurate because it takes into account your full path of travel, shifting between legs, etc, which makes your total distance run more or less than it would be if you had run in the same lane the entire run,

^Shows how stupid people are. I was doing 1600m with a fellow runner and we entered the homestretch in stride. He suddenly stopped with 100m to go. After finishing up the repeat, I jogged back thinking he may have pulled a muscle. I asked him what happened. He said his GPS indicated he had just covered a mile so he stopped. I had a good laugh.

My garmin gps is so accurate i know that every race of 10 miles or more i do, the finish line is always hundreds of yards past where it should be. also, all my garmin pbs are quicker than my official race times. Morans.

However it is noticeable that when i run faster, kilometers become shorter. clearly the garmin cannot cope when speeds become more relativistic. Its obviously not a spatial accuracy thing due to the gps positional accuracy, so it must be that the algorithm appears to overcompensate for the affect of speed on time.

Nobody ever runs exactly the race distance, whether on a track or the road. The point is, you must run at a minimum the race distance.

bartholomew_maxwell wrote:

a GPS can be more accurate because it takes into account your full path of travel, shifting between legs, etc, which makes your total distance run more or less than it would be if you had run in the same lane the entire run,

No no no no no

GPS watch with a perfect signal will be accurate to 3m. Usually it is a closer to 5. Sometimes as bad as 10m.

So image a circle around you of 6-10m in diameter.

The GPS has no idea where you are in that 10m diameter circle which is about the width of the entire track. When you go around the bend it tries to use an algorithm to estimate the path you took which it assumes to be smooth.

The track is accurate to around 1cm. It is orders of magnitude more accurate. Even if you go out into lane 2, that only really adds distance on the bends, not the straights and you are probably talking about 5-10m across a whole 5k, much smaller than the GPS could accurately determine.

If you ran the entire race in lane 2 only (ridiculous), then it would be ~100m long. Some of these instagram posters are stopping after 12 laps....

My recent 8k on a track registered 5.09 miles. Not quite as bad but still substantial.

Similar to other folks... I run on a trail with mile markers that are pretty commonly accepted to be dead-on. My Garmin picks them up pretty accurately but I find that as the miles tick by it gets more and more optimistic. Over a HM it may give me 10-20 meters advantage by 13 miles. This is a very straight trail with literally nothing that can be described as a “curve”.

[quote]big HONKING birds wrote:

I've noticed this from a few people I follow on Strava. They ran track in HS and college, yet finished their 5k TT when their watch hits exactly 3.1 (which, even if accurate, is equal to 4.98897 km), which means they ended up running roughly 12.2 laps rather than 12.5.

You're on a track, you know each lap is 400m, just count the laps

While you’re right about counting laps...if you ran just three miles on the track you would really cover Approximately 4837 meters leaving 173 meters to cover to hit 5k.

4.988 km as you said only leaves 11 meters to hit 5000....definitely NOT 0.2 of a lap. Stopping at 4.988 would be like stopping at the first exchange zone marker. So maybe 2 or more seconds depending if you are a 15 minute 5k runner or a 25 minute 5k Runner.

Of course GPS is wildly inaccurate and using it on the track only seems to amplify this. But really this post is silly

bartholomew_maxipadwell wrote:

bartholomew_maxwell wrote:

a GPS can be more accurate because it takes into account your full path of travel, shifting between legs, etc, which makes your total distance run more or less than it would be if you had run in the same lane the entire run,

^Shows how stupid people are. I was doing 1600m with a fellow runner and we entered the homestretch in stride. He suddenly stopped with 100m to go. After finishing up the repeat, I jogged back thinking he may have pulled a muscle. I asked him what happened. He said his GPS indicated he had just covered a mile so he stopped. I had a good laugh.

yeah--all of a sudden after 120 years a mile isn't 4.02 laps...

I use a GPS watch when I hand time my 10m sprint times. If my arm movement is perfect, I can get exactly 10m every time.

seattle dude wrote:

Hardloper wrote:

This is from a run entirely in lane 1

https://i.imgur.com/bjF4qQP.png

Is that Nathan Hale HS track?

Shoreline Stadium