Interval training disagreement between time and pace — TomTom Community

Interval training disagreement between time and pace

TamaTama Posts: 2 [Apprentice Traveler]
edited January 2019 in Runner & Multi-Sport
When I run in the interval training mode I find a disagreement between the laps time and the laps pace. For example, yesterday a ran 1 km 5 times with 3 minutes recovery between each kilometer (after a 10 mins warmup). When I downloaded the data on my PC, in the column "time" I read 4.30 for the first kilometer and, for the same kilometer, 4.27 in the column "pace". Shouldn't they be the same? This happens for alla laps. Pace is always faster than time. I have a Tomtom spark cardio+music.
Thanks very much.


  • tfarabaughtfarabaugh Posts: 16,727
    They are using a slightly different data series. The pace is showing a specially smoothed pace after processing (to get rid of bad GPS points and clean up the data), the time is the raw values off the watch before processing. Unfortunately, the smoothing can cause the average values to be slightly off. Generally, the pace is going to be more accurate as it is taking the smoothing into account.

    I hope this helps answer your question. If so, please mark it as a solution so others can look for it if they have the same question.
  • TamaTama Posts: 2 [Apprentice Traveler]
    Thank you very much for the reply. It makes sense but I have to add something. I didn't mention in my message that while I was running I checked the time of the fast 1 km intervals also with a plain stopwatch (no GPS), pressing start and stop at the alerts (vibration) given by my TomTom. The measured times agree better with the "time" values than with the "pace" values. Could be due to a mismatch between the alert and the actual start of the lap?
  • tfarabaughtfarabaugh Posts: 16,727
    There will be a few second delay for the alerts, but as I explained, the time value will match the watch (which you matched your stopwatch to). That is a simple counter, there is no processing done like the pace metric. The pace metric is smoothed and cleaned up, looking at all the GSP data to come up with a pace. The nature of GPS is that each data point collected is only accurate to within 15-30m of your actual location. The watch collects the data points and then tries to figure out a route using them (considering that some points may overlap or duplicate). The website then smooths the data to come up with the most reasonable route taken according to the algorithm it is programmed with. Every watch, even two of the same model, will come up with different distances, as they are collecting different GPS data, which is going to give slight variations in pace.

    You really cannot rely on the pace given by any watch down to the second, they are all estimates and should be considered a rough estimate of your pace. The goal should be to try and stay within a few seconds in either direction.

    I hope this helps answer your question. If so, please mark it as a solution so others can look for it if they have the same question.
Sign In or Register to comment.

Who's Online in this Category0