Janathon 2012 Day 2: Walk - 2.54 miles, Time - 1hr 3min, Weather - Sunny and bright but a little colder
I mentioned yesterday that I am going back to relying on just two measurements: heart rate and time. They are the most accurate information you have. Watches have obviously been around our wrists for ages and we take for granted their astonishing accuracy (so much so that I don't know anybody who is at all astonished). Heart rate monitors have only been general used since 1983 but since that time they have evolved to resist interference and do a good job of precisely counting your heart beats.
GPSs have only been available since 2003 but I would guess that they are now the dominant training tool and people grow to love them. So much so that some people think going out for a run without one is a form of disloyalty - that it cannot be a proper run if it is not validated by a full set of statistics. Some people give them names and bicker as if it is a proper relationship (I am talking about you Travelling Hopefully). But here's the thing - they are not accurate. They have been getting better but they are still not accurate.
It is undoubtably true that they are wonderful and a marvel of modern technology but it is still a mistake to confuse the precision of their results with accuracy.
This article on the subject from the New York Times amused me, especially the idea that people would contact race organisers to tell them they mis-measured their courses. Although I can shake my head and say "silly billies" it must be very tedious for the organisers.
Now I would not want to use this article as an argument against GPSs - not at all. As I have said before they are a wonder and a marvel. I would however use it as a an argument for showing that we should know the limitations of our tools and how much we can rely on them.
Today's Janathon was a walk in the park - literally. It was however very muddy and the slow pace shows the effect of trying to pick the less watery, slippery path amid a sea of mud.
(The distance measurement is, of course, as it always has been, an approximation)