just how accurate is the calories counter on Strava (for example, as it’s what i use)? It knows my height, my weight and i wear a heart rate monitor… is it simply to be thought of as a “rough estimate”?

i’m eating a fairly tightly controlled calorie per diem diet at the mo, and going for a blast on the bike tells me i’ve burned 1,200 calories so that means i can finish my ride with a lovely pizza and some beer (or some such)… right? RIGHT!?!

right!

obvz

It’s very different results if you wear a heart rate monitor versus just using say strava. When I upload from garmin (using HRM) to strava the two calories readings are completely different.

The calories deducted by any ride, regardless of distance always amounts to 3 cans of stella and some crisps I find.

Using a garmin to record to strava? I always find garmin connect gives a substantially lower calorie value than strava. If i’m feeling good I adjust my cake intake proportionally. If i’m honest 9 times out of 10 I use the less scientific eat cake and drink beer until full approach…

I do notice a lower difference on the road bike though, using HRM/cadence & speed.

On my commute I use twice as many calories if I use endomondo than if I use strava.

Have you got bikes defined? Mine defaults to my mtb so if I do a road bike ride the calories burnt nearly doubles until I select my road bike instead.

Tonight’s quick road ride was 1030 calories with my bandit defined, recalculated as 630 when I amended it to my road bike.

Not very accurate. You need to calculate energy expenditure using expired air samples and all that jazz.

I’d say it’s pretty accurate if you’ve got a power meter. You would typically estimate 1Kj = 1Kcal, but depending on how efficient you think the body is at processing food the figure might vary between about 0.95Kcal to 1.2Kcal
So if you’ve used 1000Kj of energy, estimates of between 950Kcals – 1200Kcals of cake are reasonably valid.
Strava uses about 1.1Kcal per Kj.

If you haven’t got a power meter then it will estimate your energy use. The figure is in the right ball park if you’re on a road bike, and the height profile is correct for your ride, if not, it’s a pretty random stab in the dark.

Here is a readable primer on the different algorithms garmin devices use to derive the calorie figure from heart rate etc

http://www.dcrainmaker.com/2010/11/how-calorie-measurement-works-on-garmin.html