I've had my Timex Bodylink system (watch, HRM, GPS) for three weeks now, and I must say that this is
the best training device I have ever used.
I find no problem in wearing the GPS device on my upper arm - felt a little strange at first, but
after the first mile I didn't even notice it. Sometimes it slips a little, but a few seconds to
readjust I find is a small price to pay for the functionality.
As for the accuracy, I have no idea how accurate it is, since I have no other means of measuring! I
was always used to estimating by distance (running more by time than distance covered), but the GPS
device really takes the guesswork out of it all. According to the documentation it is 99% accurate.
To be honest, I see it as no real problem if accuracy is a little off on the hills (my courses are
pretty hilly). What's is 0.2 miles difference on a 90 minute run? I doubt that even professionals
would be that bothered.
The GPS really becomes useful for pace / speed, and mapping that to heart rate. I used to be one of
those runners who would hare off down the road until my lungs collapsed, recover for a minute, then
go again. But now, even after just a few weeks, I am already reaping the rewards of controlled pace
/ hr running – taking things a little slower.
The only annoying feature of the Bodylink is the variability of the pace readouts. It reacts quite
slowly to pace changes, and seems to average out over the last 15 seconds or so. There is a
feature to smooth the pace readout, but this simply averages out even further. The Timex does not
like pace changes. The reason – the GPS broadcasts is signals every 3.5 seconds according to the
docs. Any pace changes in between will go unnoticed, so it could be around 7 seconds before the
reading is accurate. It's only a minor fault and I image this functionality will approve as the
devices are enhanced.
The biggest problem with Bodylink is the lack of a Data Recorder – everywhere is out of stock of
these little beggars! But they should be available any time soon.
To make it the ultimate, I would like to see position recorded as part of the data logging, so that
a course could be plotted onto a map. It would also be nice if the GPS receiver were Bluetooth so
that I could carry a PDA with mapping software to get an instant position whilst on the long treks.
Maybe that's something for the future?
Overall, I thoroughly recommend this Bodylink device. The best training kit I have ever used.