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It looks like I burn 100 Calories per hour on average. Do activity trackers report the extra burn due to the activity, or the total including the base.

To put it in other terms, if it says 800 kcal for an hour's ride, can I eat an extra 800 kcal or only 700?

Duncan McGregor
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    That question is probably best directed to the maker of your particular activity tracking tool. I know that Strava's estimate is calculated from your weight + your bike's weight, and the distance and speed and elevation changes, but I'm unsure if it includes any base rate. I'd guess not. – Criggie Nov 15 '15 at 09:47
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    You shouldn't really put too much attention at what your activity tracker says on calories consumption, that's more like a rule of thumb in my experience, if you use a heart rate monitor (which takes also into account the BMR) you'll see the difference. – Ende Neu Nov 15 '15 at 11:19
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    You can answer your own question for your activity tracking tool by testing it. Start an activity while sitting still for an hour, eg while watching a movie, and see how much energy it thinks you have used. – andy256 Nov 15 '15 at 12:40
  • Sitting still watching a movie? I have a turbo for those hours! – Duncan McGregor Nov 15 '15 at 19:12
  • This is specific to the actual tracker used, and even then a tracker may change strategy. – Móż Nov 15 '15 at 20:25
  • I'd say that without a power meter- it really doesn't matter. I have done the same ride 300 times (commuting) and the figure can vary 30% (either Garmin or Strava). Wind/gradient can be so local, GPS really isn't going to pick up on this. So, if you want accurate, buy a power meter, else, just use it as a "best guess". – AliGibbs Nov 15 '15 at 10:37

1 Answers1

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Using my two Garmin devices, I lay down for 30 minutes watching a film.

Both recorded an average heartrate of 60 bpm. The 810 gave 35 kcal, the 910xt 45 kcal

So 70 - 90 kcal per hour : 1680 - 2160 kcal per day. It looks like the BMR is included in the figures, so that I have to subtract 100 kcal an hour or so to estimate my additional expenditure.

Garmin Connect shows the same figure as the device. Syncing the data over to Strava, it turns out that Strava doesn't estimate Calories without a GPS track or power data. So it looks like I'll have to try the next experiment in the garden.

Upate - I've finally gotten round to sitting still in the garden for 10 minutes with the 810 and a heart-rate strap. The result - Garmin Connect shows 16 kcal - my BMR, whereas Strava showed 0 kcal. So it looks like Strava only shows work based on the track data.

Update - I freewheeled down a 4 minute descent with my Vector pedals measuring no power input. The Calories consumed as displayed on the 810 did not go up at all. So it looks like the Garmin is inconsistently not including BMR when it has a source of power data.

Duncan McGregor
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  • It might be useful to edit the device details into the question so it looks more as though you answered the question asked – Móż Nov 15 '15 at 23:28
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    Sounds like a boring film. Waiting for the next experiment report :-) – andy256 Nov 16 '15 at 00:22