I wear girl running shoes cause I have small feet

I have the Garmin 610 and it's very rare for a half marathon in Utah to be anything less than 13.2 GPS-measured. 13.2 is usually what certified courses yield on GPS, for what it's worth.

Nice race and congrats on 3rd place. That's $100 right?

Yes Riley I got $100 which payed for the race and a bit extra. I talked to Brett for a little while. Thanks for all the advice you have been giving me. I feel like I am so close to more big PRs in the 1/2 and full before I get too old. Turning 38 this week.

I will post pictures when I get home to Rock Springs. Had a fun but busy weekend. Spent time with my grandma visiting for MD, went to Provo to see my sister new baby and had a combined Bday party for my sister and I.

I have a 620, but I don't use half the features on it. The vibrate feature is nice, but the 220 also has this (if you've ever run a race with a bunch of watches beeping this eliminates any question that's it you).

The recovery adviser function is a joke. It's designed for hobby joggers. That's an extra feature the 620 has that the 220 doesn't have. I think the 220 is the way to go for the money. The other features need to be refined for them to be useful.

I've never run a certified half that has come up long except for a course that was rush re-certified due to flooding. The course was definitely long.

However, I notice that most folks in Utah will regularly get closer to the 13.2 mark. That's likely a good thing because a course should measure slightly long given that certifiers measure long (I forget the percentage) for margin of error in the event a record takes place and the course is found to be short. You can read about the London Olympic Marathon measuring process in the link below. I have no idea if all certifiers use the same method but it's interesting:

http://www.wsj.com/articles/SB10001424052702304765304577479061991721208

Congrats on the PR and the chunk o' change!

It is rather ironic that a GPS can be trusted for aviation, but for running. The reason is that the GPS can tell you where you are with the precision of 10 or so feet. For aviation it is usually good enough. For running, you want to know ho far you went, not where you are. So suppose we sample once a second. Consider something like this - a possible scenario for at least a part of your run. You are running in a straight line. First sample comes out to be 10 feet to the right of you, second sample 10 feet to the left. Let's say you are running 5:20 per mile, so 16.5 feet per second. In one second you have actually run 16.5 feet, but the GPS will think sqrt(20^2+16.5^2) so it comes out to about 25.9, or about 57% error in just one measurement that will never be compensated later on.

If you are moving at car speeds, or even better, airplane speeds, the error drops significantly because 10 feet is a small number compared to the distance you can travel during the sample window (1 second).

In practice things are not quite that bad all the time, but a couple of fairly short lasting glitches that fall within the normal operation of the GPS specifications are sufficient to add 1% distance overall even when the signal is perfect and you are running straight. When you are not running straight and on top of it there is interference and the signal gets distorted, we can see much higher deviations.

So GPS, when it comes to running, is not a precise instrument, and in spite of all the advanced technology, does not and will not for a long time be close to the good old wheel measurement and landmark marking method. Which is why USATF and other organizations insist on the low-tech method of course certification.