Summary: value calculations in SportTracks

Frequenly Asked Questions

Moderator: FAQ Moderators

Summary: value calculations in SportTracks

Postby CHnuschti » Sat May 23, 2009 10:47 am

This section is a summary of the different settings which do influence the calculations within SportTracks.

Question:

What settings do influence the calculations of values in SportTracks?

Answer:

SportTracks calculates various values, such as averages, sums, maximums etc..

The calculations of these values depend from 4 types of settings:
a) Pauses handling => See pauses FAQ for details
b) Data smoothing => See smoothing FAQ for details
c) Data cutoff (cadence & power) => See cutoff FAQ for details
d) "Flat" zone of the climb zones of the categories => See elevation FAQ for details

but depend to some extent also from
e) "Manually entered values" => See manually entered values FAQ for details
although this does not represent a real calculation, but is just a takeover of manually entered and/or values calculated within devices,
as well as marginally from
f) "Body" values in the Athlete view => See Athlete FAQ for details


Apart from these mentioned settings influencing the calculations, SportTracks does not apply any further "special", "automatic", or whatever calculation/filtering etc.. It uses the data "as delivered", without additional alteration.

SportTracks will chew through the detailed record delivered by the device and determines maximum values, averages, sums etc. ON ITS OWN, by default it does not take over the averages, sums etc. which the devices do determine/calculate themselves (Exception: energy (="calories"), see here, points 7)&9) and here).

All averages displayed in lists and summaries are calculated/averaged over time, NOT over distance. In the graphs, if you select a hole graph, you will get different averages, depending from the type of graph (over time/over distance) you choose. In averages calculated over distance, values recorded at high speed get an overproportional weight.
Last edited by CHnuschti on Tue Jun 23, 2009 4:17 pm, edited 8 times in total.
CHnuschti
 
Posts: 275
Joined: Tue Feb 13, 2007 3:28 am
Location: Switzerland

Postby CHnuschti » Sat May 23, 2009 11:06 am

Question:

Why is the value I get from software X / device Y / internet page Z different from the value SportTracks shows me?

Answer:

Some general hints, for device and/or data specific details see detailed FAQs etc. (Time, Elevation,Distance).

- Make sure the device/software has/works with the same settings a) to d) mentioned as in SportTracks. If this is not the case, you can not compare the values. Some devices/software, when calculating averages etc., also just apply some "special treatments" to the recorded values "as delivered", which in worst case are not documented and/or can not be switched off.

- Calculations in SportTracks (or other software!) can generate slightest differences due to rounding issues or small differences between large numbers and the like (depending from the math algorithms used), which can cause for example that your average heart-rate is off by 1 BPM or similar. Well, don't take your training too serious.

- Devices performs some kind of smoothing for the data. For instance is the fastest speed a device reports normally lower then the fastest speed between two points. The smoothing algorithms in the devices are normally not documented.
Last edited by CHnuschti on Tue May 26, 2009 7:24 am, edited 4 times in total.
CHnuschti
 
Posts: 275
Joined: Tue Feb 13, 2007 3:28 am
Location: Switzerland

Postby CHnuschti » Sat May 23, 2009 11:13 am

Question:

Device/software specific hints?

Answer:

Garmin:
- Forerunner and Edge series offer "smart recording" or "every second recording". "Smart recording" in average usually has a record entry every 5 seconds, the manual states: "Smart Recording picks up key points where you change direction, speed, or heart rate". However, the device continuously checks the sensed data and for example can detect a maximum value in between, which will not be entered in the detailed record, but is just saved internally as kind of "highest sensed maximum". The device in its summary will present you this value, but since it is not in the detailed record, SportTracks will not reproduce it but present you the maximum value it has filtered out itself from the detailed record.

Smart recording can be seen as smoothing in the device. In normal situations, Smart recording is better:
* Longer recording time Importing Activities
* Better distance calculations GPS distance calculations

Reasons to use Every second recording:
* Use with a power meter, where the second resolution is interesting.
* No GPS activities (Indoor), where smart recording will be very sparse (maybe every minute).
* You absolutely want to make sure the device records the max heart rate (smart recording can skip this otherwise).
CHnuschti
 
Posts: 275
Joined: Tue Feb 13, 2007 3:28 am
Location: Switzerland


Return to FAQ

Who is online

Users browsing this forum: No registered users and 2 guests