Apple Watch: Why does indoor walk burn more calories than outdoor walk?

SJBermingham

Hello,

I was selecting ‘outdoor walk’ on my walks outside, and also walks on the treadmill. By chance yesterday, I decided to track my treadmill walk using ‘indoor walk’ selection and I noticed the watch log significantly more calories than normal. Today I’ve read online that ‘outdoor walk’ tracks by GPS, and ‘indoor walk’ tracks using heart rate.

But I just want to know if the ‘indoor walk’ calorie tracking is accurate? I would rather underestimate my energy expenditure than overestimating it- and it just seemed like the indoor selection calories were very high.

Many thanks in advance 🙏

sijomial

Counting heartbeats doesn't equal counting calories. You might get lucky and have an average exercise HR, or you might not.
Your device also might be estimating gross calories not net which is OK if you are using it as a 24hr tracker but not so good if you are trying to estimate just the extra calories you burned through your exercise (eating to your Apple Watch goal or a MyFitnessPal goal?).

Also especially indoors getting hot elevates your HR giving an exaggerated estimate.

Personally I would go by distance assuming you aren't walking an significant incline or alternatively holding on but GPS doesn't work on a treadmill as you aren't travelling anywhere.
Bodyweight in lbs X miles walked X efficiency ratio of 0.3 is what I would use for a net calorie estimate.

Duck_Puddle

When you say significantly more than outdoor walk, do you mean for the treadmill walks you recorded as outdoor walks or walks you did outdoors (that you recorded as outdoor walks) that are the same distance/time/etc?

If you recorded treadmill walks as outdoor walks-the distance recorded would be very close to 0 (although it would record something and the actual gps dot would move around a lot so you would have some distance).

My treadmill activities seem to record based on what the Apple Watch estimates as my distance covered (it often doesn’t find a heart rate for a good portion of my walk/run so that’s not the only sensor it’s using).

I would expect treadmill walks recorded as indoor walks vs outdoor to show much higher distance (and corresponding higher calorie burn).

If you are comparing indoor tracked as indoor to outdoor tracked as outdoor-see I’d the distance your watch records for an indoor activity matches up to the treadmill (give or take - it won’t be exact).

And you only went to be using the active calories (not total). My watch comes pretty close to what what I would expect for walking (when I set it to indoor on the TM and use active calories).

SJBermingham

@Duck_Puddle thanks for your response.

So the Apple Watch has picked up the distance as I’ve been going for 5km walks, both indoor and outdoor. Until yesterday, I was logging all walks as ‘outdoor’ including my treadmill walks. I did notice the treadmill logged it as slightly further than the Apple Watch. TM was saying around 5.7km whereas watch would say 5km.

When I was logging them as ‘outdoor walk’ on the Apple Watch, I was burning around 250 active calories. But when I logged one of my 5km walks as an ‘indoor walk’ - it said I burned ‘384 active calories’ in 55 mins (av heart rate 135), which seemed like a lot considering I usually burn around 420 doing a 45 min spin class (av heart rate 172).

So it just seemed like when I logged one of my treadmill walks as an ‘indoor walk’, the watch overestimated it? Or do you think it’s accurate?

Thanks again

SJBermingham

@sijomial appreciate the response.

I’m going by ‘active calories’ logged on the watch, not total.

I’m comparing a few 5km walks I’ve done. When I recorded them as ‘outdoor walk’ on the Apple Watch, I was burning around 250 active calories for 5km. But when I eventually logged one of my 5km treadmill walks as an ‘indoor walk’ - it said I burned ‘384 active calories’ in 55 mins (av heart rate 135), which seemed like a lot considering I usually burn around 420 calories doing a 45 min spin class (av heart rate 172)??

The formula you’ve given would suggest I burn around 115 on a 5km walk (3.1 miles).

124lbs x 3.1 x 0.3 = 115 calories?

MelanieCN77

You may want to reset your Watch and use the correct presets. It's learning and now extrapolating from bad data.

SJBermingham

Oh really, ok maybe I’ll reset it tonight so, cause really seemed like it overestimated the calories.

Thanks @MelanieCN77