Treadmill mileage vs. GPS app?

Last night I ran/walked a 5k on the treadmill and it said I finished in 31:30. I also had my Nike+ gps app running and it said I had only completed about 2.5 miles in that time. I finished up what it said would be a 5k and it took me 36:31. This seems like a pretty big difference to me. I'm running a 5k race in sept. and would like to at least get down to under 30 mins, so I'd like to know how close I actually am with my pace. I'm currently alternating between a 6.7 mph running pace and a 4.0 walking pace (trying to lessen the time walked each time). I can't run outside because I'm a stay at home mom and have to do it while my 2 youngest are sleeping. Has anyone else had an issue with their GPS app or treadmill being way off? Which would be more reliable?

Replies

  • Tony_Brewski
    Tony_Brewski Posts: 1,376 Member
    How reliable is the App? All the apps I've tried glitch out. The phone switches towers and there'll be a loss or gap in the distance. If the phone does something else... change song on mp3 play list... get a text... auto updates... these can some times cause a hiccup with the app as well. Best thing to do is map out a route and run it ... use your app and a stop watch. Compare the two. If they dont match up then you'll know somethings a miss.
  • scottb81
    scottb81 Posts: 2,538 Member
    GPS isn't accurate on a treadmill as GPS requires you to move to calculate a distance. The app should have said you ran 0 miles.
  • katiegregory23
    katiegregory23 Posts: 26 Member
    The app has a treadmill option, so it does calculate. I guess it's just not as accurate. Thanks!
  • DavPul
    DavPul Posts: 61,406 Member
    What am I missing here? Does your treadmill move thru time and space like the tardis? How can a gps app, which tracks movement thru space be used to me measure distance on a stationary treadmill? Or were you actually using a step counter? If step counter, then it's just inaccurate by nature.

    Also, when you're actually running on pavement your fatigue level will be much greater and your pace slower than the treadmill. So if you're trying to finish under a certain time I'd switch 90% of my training to running outdoors, preferably on a similar course to the actual race.
  • heatherrose9
    heatherrose9 Posts: 122 Member
    For races that I've done mostly treadmill training, my race finish is usually pretty in line with treadmill. Additionally, when I run outside I find myself pretty close to my treadmill pace! However, I do more of a steady pace rather than the intervals you are doing so I could be completely incorrect:)
  • Bronx_Montgomery
    Bronx_Montgomery Posts: 2,284 Member
    Im surprised you actually received a calculation. The GPS app would require you to move from one location to another not just in the same position like you would on a treadmill. I wouldn't have that going while on the treadmill. It only works if you are actually outside going that distance.
  • katiegregory23
    katiegregory23 Posts: 26 Member
    It has a treadmill "indoors" option. I was using it to get used to checking split times/mileage during the run. I'll just ignore it while running indoors now, though and calculate the very rare times I am able to get outside. Thanks for your responses!
  • muddyventures
    muddyventures Posts: 360 Member
    I would just compare your treadmill mileage/time with your outdoor run of same mileage. I don't count on my to be accurate, just to give me a gneral idea of what I'm running etc.
  • omma_to_3
    omma_to_3 Posts: 3,265 Member
    The treadmill should be quite accurate, since the length of the belt is a fixed, measurable distance.

    I'm not sure how the Nike+ app works, but I would assume it bases it on the number of strides, like a pedometer, when you're indoors. It wouldn't use the GPS function at all. Check the app, and see if you can modify the stride length to be more accurate to your stride.
  • katiegregory23
    katiegregory23 Posts: 26 Member
    I'm using the app that doesn't require the sensor. I've used the sensor in the past and it does calculate by strides, but wasn't very accurate for interval training. I'm not really sure how they set it up to use the gps function inside, I just know they did (not very well it seems). I'll definitely be calculating out my outside runs when I can get them in and compare accordingly. Thanks for the advice!