Linda L. said:Hi all - hoping this is an okay group to join - I'm not
new to running but after having my third and FINAL child,
I can really get devoted. Doing pretty well -surprising
myself - really liking it this time.
Anyway, I am curious about the new GPS's vs. a regular old
pedometer. I'm always driving here and there to know "how
far I ran". I can sort of do it by pace but I always just
"have to know".
Never used either of the above and would love to hear what
you all think - thanks - Linda (PS: If there is a better
group for a relative newbie, let me know).
Yep, you're in the right place. Since much of this
technology is constantly developing, we're all newbies 🙂
Methods of measuring distance include maps, bikes, cars,
pedometers, GPSr devices, accelerometers, and maybe some
others I'm forgetting.
Pedometers count only steps so is probably not very accurate
for distance.
GPSr devices depend on its location (presumably on your arm
or pack), satellite configuration, and clear view of sky (no
mountains, tall buildings, or wet leaves in the way).
Require no calibration and can be used while mt biking, xc
skiing, kayaking, etc.
Accelerometer devices depend movement of foot and do best
when calibrated, usually on similar surface in same pair of
shoes. From various comments on threads, I'm getting the
feeling that a firm (hard dirt) vs soft (deep grass) might
affect the readings and might need to be calibrated for,
but not sure.
Maybe someone can fill in the names of the assorted devices
in the various categories since I haven't been following the
exact models. (I know what I'm waiting for so haven't
worried about the others.)
Here's a simplified (I hope) flowchart that I think
summarizes several threads - at least with regards to
distance estimates (pace is another issue). Others might
argue with some of the details and will chime in, but I
think this hits the main points.
1. If you run on snow-free roads in same shoes and can
get decent GPSr reception and don't care about other
applications, you can probably use either
accelerometer or GPSr.
2. If you run on roads and generally have trouble with
GPSr reception (tall buildings or poor satellite
configuration), then the accelerometer devices might
be better.
3. If you run on trails with easy footing and few hills, I'm
guessing that might be similar to roads.
4. If you run on trails where your stride is
constantly changing because of obstacles, mud,
snow, hills, etc, then
a. If you can get reasonable GPSr reception, that
might be the better way to go (also more flexible
since it can be used for an assortment of
activities like biking and skiing).
b. If you can't get decent GPSr reception, then I'm
guessing a more sophisticated accelerometer
(maybe one from Dynastream, *not* Fitsense as
they acknowledge that their device wasn't
intended for that) *may* work - depending on
degree of accuracy you want. (I don't have one so
this is really a conjecture.)
c. If the accelerometer isn't accurate enough and
GPSr reception is poor, then just go run and
enjoy it - unencumbered by numbers - or use a
random number generator for your log book 😉 This
is where I use the old fashioned method of maps
or poor GPSr (assuming I got some reception) and
recognize the error might be 20%.
You might google group search for discussions on this ("gps
accelerometer" will pull up a bunch of good threads) within
the last few months. At this point, many people have been
using an assortment of devices and have a feeling for what
works and doesn't work in their circumstances, but
everyone's circumstances and needs are different. No device
on the market works for everybody.
FWIW, I run mostly trails and train mostly by time and
effort (hrm) (that is, distance isn't a primary parameter
for me) with approximate distances from an electronic map
where I have placed gps tracks of my main trail system.
Occasionally some have been verified by mt bike. We
frequently have poor gps reception, but I'm not convinced of
the existing accelerometers working here (they might). I
sometimes (once a month) take a GPSr (a "real" one so I can
map a new trail occasionally, mounted on top my camelbak) to
get approx distance and elevation change. Carried in my
hand, I get terrible results, usually. I also ski and
snowshoe run so like the gpsr flexibility. However, I am
considering getting the new, not-yet-to-market Polar hrm
(S625x with Dynastream accelerometer), but primarily because
I wanted to upgrade my hrm and can probably wait until they
get the initial glitches worked out.
I think I do have a bias toward gps devices though until I
see accelerometers working on snowy, hilly trails - and they
are more flexible as to activities. With gps things, I can
see where there's problems by the gaps in the track log and
know the estimates will be poor to useless.
Dot
--
"Success is different things to different people" -Bernd
Heinrich in Racing the Antelope
