I have noticed that my Garmin isn't very accurate on a track but on other measured courses its pretty accurate. Why is that?
I was doing 3k repeats on a track that I know is accurate (wheel measured it before to be sure) and my Garmin kept showing 3.12k for each repeat. But in a race course or other wheel measured road course its always much closer, well within the normal variation for tangents.
Does the 2 x 180 degree turns per 400 meters mess with the GPS measurements?
Thoughts?
I think it's the turns. Mine (305) shows a mile at a bit over 1500 meters but on the roads seems fairly accurate. I just use a Timex Ironman on the track.
I agree that the 405cx does not work on tracks - said I ran a 1600 in 441 when the actual time was 5:07.
But on the roads it is dead on accurate - must be that running around in small circles confuses the GPS .
Why would you even bother wearing a GPS on a track? And did you really wheel it to make sure?
Shh! Don't tell the youngsters! They may quit buying the Cool New Stuff!
What if they find out that chip timing is not as accurate as they've been telling themselves? Wow!
I heard that if you put white tape on your Garmin then it will give you a wrong reading. Also, if you sweat a lot it effects the watch. Also, if there is a student band playing on the track, it can have an effect on your watch too.
No Way wrote:
Why would you even bother wearing a GPS on a track? And did you really wheel it to make sure?
Because its my running watch now that the battery is dead on my Timex Ironman, I use it to time all my runs.
Yes, I did measure it a while back with my meter wheel because its a middle school track and I wanted to make sure it was accurate because that is where I do all my track workouts (it's a good warm-up jog distance from my house).
Garmin User wrote:
No Way wrote:Why would you even bother wearing a GPS on a track? And did you really wheel it to make sure?
Because its my running watch now that the battery is dead on my Timex Ironman, I use it to time all my runs.
Yes, I did measure it a while back with my meter wheel because its a middle school track and I wanted to make sure it was accurate because that is where I do all my track workouts (it's a good warm-up jog distance from my house).
College, middle school, city park, as long as it was built in the last 25 years its 400m.
Also wheel measured it to determine exactly where the 300 meter mark is as well as the 150 meter point as I occassionally use these distances in my workouts.
So now I have the peace of mind knowing that track is accurate and where all the distance marks I am interest in are located.
I have the meter wheel, so why not use it.
You will almost have all the marks you need if your track is measured and marked for standard events (100m, 200m, 400m, 400h, & 4 x 100 relay. You would never have to measure more then a few meters from any of these marks.
Example: 300 meters. You have a bunch of options. The track is marked every 100 meters. From the common finish 1500m start/ 200m/ 100m. Pick any for your start. No 1500 meter start? It's the middle of the first 4 x 100 relay exchange zone.
Example: 150 meters- Common start finish to the 4th hurdle of the 400m hurdles (lane 1)
Obviously, you increase the accuracy of your measurement by reducing the amount measured with a wheel on a track.
The answer to your question is: Yes it is because of the turns. Basically the Garmin measures point to point to point and sums up the measurements. It applies some sort of smoothing algorithm to the data as well and that apparently makes running on the track seem like you've gone farther than you really have. It's only logical that it would be significantly off when you are so frequently turning.
I find that on a regular course without too many road turns, the 305 and 310 are usually accurate to within 1/100th of a mile, per mile. Roughly 4 to 5 seconds.
I also use my Garmin to record all my workouts but on the track I usually just turn the GPS off and use it merely for the lap times.
My Garmin 110 consistently overestimates the distance on the track too.
I sometimes use the Garmin because it has a much bigger display than my main watch.
I run in the second lane and so am not certain of the average error - but on 4 lap reps the mile pings at slightly different points as I finish.
Nevertheless we are only talking a couple of yards/metres so that's not a worry. In any case I'm using it purely as a timer.
If you look at the specs in your manual it should state
% of error, I usual average 3% in my favor all the time.
I'm in Korea- the only track available is on the army base which according to the sign, is .2 mile in lane 3. I wore the Garmin to guage where 400 meters might be.
David Katz wrote:
You will almost have all the marks you need if your track is measured and marked for standard events (100m, 200m, 400m, 400h, & 4 x 100 relay. You would never have to measure more then a few meters from any of these marks.
Example: 300 meters. You have a bunch of options. The track is marked every 100 meters. From the common finish 1500m start/ 200m/ 100m. Pick any for your start. No 1500 meter start? It's the middle of the first 4 x 100 relay exchange zone.
Example: 150 meters- Common start finish to the 4th hurdle of the 400m hurdles (lane 1)
Obviously, you increase the accuracy of your measurement by reducing the amount measured with a wheel on a track.
You haven't been to too many middle school tracks have you?
They don' tun the 400 meter hurdles and they only put the exchange zones in not each 100 meter mark (i.e.e no 300 meter mark).
Would wearing a foot pod with the 305 affect accuracy?
College, middle school, city park, as long as it was built in the last 25 years its 400m.
I worked at a high school that built a 400 yard track in 1998. The jack ass athletic director pulled some book off his shelf from the 1940's and gave it to the construction crew.
Another screw up was the crown of the football field was like 6 feet high. You couldn't see the opposing team on the other side of the field.
"You haven't been to too many middle school tracks have you?
They don' tun the 400 meter hurdles and they only put the exchange zones in not each 100 meter mark (i.e.e no 300 meter mark)."
I have been to MANY high school/ middle school tracks on Long Island, NY and they all have marks for the 400 meter hurdles and the 4 x 400 relay. If there is no 1500 starting line you only need to measure 10 meters from the start or end of the first relay exchange to find the center of the zone - 300 meters to the finish.
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Pretty hard to see what the connection between chip timing and GPS distance measurements is.
Can you elaborate?
I have experienced the same thing on the track with the 405.
It happens and there is really no way around it since it pings every few seconds(guessing on the timing) and then connects the dots. It also happens if you run under heavy tree cover and loose signal for a few seconds. On one of my old routes it looks like I'm running on water when I cut a corner under some trees next to a pond.
I also did a marathon with it that was dead on perfect 26.21mi...there's no arguing with that in my book.