Photo courtesy of Andrew King - D4 Productions

Tuesday, August 31, 2010

11 myles - 1.17:02

Coyote Ridge - 7 AM
50s, clear, dry
mind/body - still feeling solid
easy effort

I've been walking Jaxon to school in the morning so it's been an easy spring board to get the run in from there. The chill is in the air, as was apparent yesterday at 14K, but it sparks some sort of motivation for me. A mere 7:03 pace today with 1000 ft of climbing and felt great doing it. I hope to hit somewhere between 90 and 100 for the week (290 for August and 2122 for the year) and start a slight taper from there for The Bear. On Thursday Tim Long and I are going to do 41 on the Colorado Trail starting at 6 AM at Indian Creek TH. My wife will pick us up at Wellington lake road. Come along and get some good myles in for a fall race.

On another note, I've been toying around with my watch and yesterday as I sat on the top of Mt Bierstadt with Tim (and his Timex GPS watch) we talked about GPS vs. barometric elevation. I had thought barometric was more accurate but didn't know why... I emailed Rick Merriman this morning and here is his explanation that makes total sense:

GPS is always the most accurate if it's getting a good signal. The reason is because the signal is simply sending stored data to the watch. The watch isn't calculating anything it's just receiving data that has been stored in the satellite sending it.
Your barometric pressure watch takes a pressure reading, then calculates what the altitude will be. So, since pressure changes in a spot, then the altitude reading will change slightly as well. These changes are very little though. The pressure on top of Mt. Bierstadt will be different today than it was yesterday so it's possible that if you went up again your altimeter would say something different than 13,923. However, it will be less than 100' difference way up at 14,000'. Barometer watches offer some important things that GPS watches cannot. 1) They don't need a signal, barometric pressure is everywhere so the watch can always calculate. 2) Battery power on GPS is always an issue, just about 8 hours, while the barometer watch uses a basic watch battery lasting about 2 years. So power and signal are pretty important and GPS watches can have issues with these 2 things.

So my take on this is that barometric is better for trail runners who are running in the trees for a long time. If you've got a clear view of the sky for a shorter run then GPS may be the way to go. For me, barometric make more sense.
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