5k measurements

[shoeaholic]

This is the second time this happened to me.  I use my nano with Nike Fitness. I use it for all my workouts and also use it during 5k races.  This weekend it measured 5.48k at the end of the race. This kills me because it is telling me during the race that I am at say 4k but the mile markers on the route are off.  So the question is, is the Nike Fitness off or is there an inaccuracy to the measure distances on a 5k. I tend to think the Nike is off and if so how do I calibrate it so its in sync with the route.  

It messed me up because I thought I was at a pretty good pace but turned a corner and almost died when I saw how much further I had to go

thanks for any ideas on how to deal with this!

[gummybear]

Two explanations. First, when they measure race distance they do the shortest route, eg, hugging the turns, inside path etc. Second, when you run, you do a little bit of dodging other people, swerving etc. which adds distance.

This is a good explanation www.dcrainmaker.com/2009/03/racing-line-understanding-how-courses.html

Although, .4 is a huge amount for a 5K. I typically get .2-.3 extra on my Garmin during a half marathon.

ETA: I am an idiot. I see you are talking .4 extra K, not miles, in which case I would say that is completely normal. I just always have it in my head that I need to add a little bit of distance after my gps hits the "official distance"

[shoeaholic]

Thanks! I try to do a lot of the hugging the road and this was a crowded start (almost 500 people) so i did have to do a bunch of dodging. The last time this happened it was only .25 so I really thought this one was extremely different.

Yes, was .48k but still enough to mess with my head. 

[gt7301b]

I only know of two race courses that measure exactly 5k on my Garmin.

When Mr. GT and I race together we are routinely have between a .1 and .2 mile difference on our Garmin. He tends to be near (at) the front and have less weaving to do than I do, but I am usually the one who runs fewer miles.

[pamela]

Is Nike Fitness GPS or a pedometer? If it's not GPS, it's highly variable based on what you have programmed in as your stride length.

[breezy8407]

.48k is only about a 1/4 mile, so that's actually not too bad

I ran a 10k a few weeks ago and ended up running 6.35 instead of 6.2 miles. The beginning of any race is so hard to avoid adding a little extra, unless you are at the very front.

[taratru]

You can recalibrate your Nike thing, can't you? I'd start there.

[shoeaholic]

It's not the GPS, just the nano app that track time, distance, pace and such. I wish it had GPS. it does have a calibrate setting that I always hit when done (it asks after each run if I want to calibrate) and I do. I think I'll just start adding bits to my work out so that I get used to running the extra distances. I had actually started to do this anyway to try to improve my times so now I have extra incentive to bump up my distances.

Thanks for the input.