Most accurate calorie indicator.

[fenlandpsychocyclist]

I understand many cycle computers have to be set with riders age, weight, height, etc, before the devices can work out calories burnt on a ride.

I have an android phone running garmin fit, a forerunner 305 watch and an edge 800 ... each can show a wildly different "calories burnt figure" when all three are used on the same ride.

Today i did 70.1 miles, with about 1100 feet of combined climbing.

Bearing in mind all the basic parameters were set identically in all devices, and all devices are gps based so they know elevations/speed/etc the results were:

Phone: 3700 calories
Watch: 3500 calories
edge 800: 2017 calories

Now most people would be happy to quote from the garmin fit app up the pub, before eating
3000 calories of pub food whilst "thinking" they are still in a calorie deficit.
Myself ... i think the 800 may be nearer the mark.

But why? What extra data is the 800 taking into account before it comes up with its calorie figure?

*EDIT* I should point out both garmin devices were receiving my heart monitor strap and cadence detector ... where the phone wasn't receiving either.

 

[Mrbez]

I would be interested in this too.

I did 22 miles today with 1250ft of climbing.

My Edge 705 said 1325 calories burned.

 

[lulubel]

The forerunner 305 uses speed and distance to calculate calories, even when you have the HRM connected. The edge 800 uses your heart rate.

 

[vickster]

All the sites I have seen say 30-40 cals per mile as an estimate, so for 22 miles, 600-850 ish

 

[gaz]

Between 2000 and 3000 calories burnt on a 70mile ride.
Certainly something wrong there

 

[broomwagon]

Graham Obree is right, we pay too much attention to computers and gadgets and not enough on enjoying our ride...Phone, Watch, Edge? Mind boggling.

 

[fenlandpsychocyclist]

Between 2000 and 3000 calories burnt on a 70mile ride.
Certainly something wrong there

Would have been more ... but i kept my speed down purely so my legs are ready for another ride tommorow. I've done this exact ride before using the edge 800 with an average speed 2.5mph faster ... and an extra 500 calories burnt. This supports what has been said about the edge 800 taking the heart rate into the calorie calculation system.

 

[fenlandpsychocyclist]

I

Graham Obree is right, we pay too much attention to computers and gadgets and not enough on enjoying our ride...Phone, Watch, Edge? Mind boggling.

I did keep grabbing the camera on the move taking pictures ... so i did actually enjoy my ride. Most of my daylight rides are superb because i always ride solo and can change my route on a whim. Best when i'm on a mountain bike because that doubles the amount of routes that can be used.

 

[gaz]

Would have been more ... but i kept my speed down purely so my legs are ready for another ride tommorow. I've done this exact ride before using the edge 800 with an average speed 2.5mph faster ... and an extra 500 calories burnt. This supports what has been said about the edge 800 taking the heart rate into the calorie calculation system.

I was hitting to the point that there is a difference between calories and Calories. The daily calorie intake for an average male is 2,500,000 calories. The daily Calorie intake for an average male is 2,500 Calories.

 

[fenlandpsychocyclist]

I was hitting to the point that there is a difference between calories and Calories. The daily calorie intake for an average male is 2,500,000 calories. The daily Calorie intake for an average male is 2,500 Calories.

Haha!! So shouldn't we be speaking in terms of kCals ... or is it Kcals??

 

[gaz]

Haha!! So shouldn't we be speaking in terms of kCals ... or is it Kcals??

kcal. yes.

 

[GrasB]

A rough estimation. 100Wh = 86 kCal. Your body is about 60% efficient at producing power iirc so that's 143kCal. So for a 12st man doing a flatish 70 miles averaging 100w (14.8mph) we get 677 kCal.

 

[Hacienda71]

The phone apps are not accurate. My commute is all uphill and yet the calories expended going to work are the same as coming home from work using endomondo. I could freewheel for a large proportion of the homeward leg.

 

[HLaB]

I've no idea how GPS sites calculate calories etc, Garmin Connect reported 2994C, Strava reported 2238C and RwGPS reported 3274C for the same 66mile ride yesterday

 

[lulubel]

You'd think if they were all using speed/distance/terrain, they'd all give the same figure.

To the OP, they're all estimates, but the edge 800 is closer than the others. Garmins, in my experience, still tend to be rather generous with the calories most of the time, although it does vary.

I'd love to know how they calculate it because I can do exactly the same amount of time, same average and max heart rates, but a real ride on the bike will give more calories than on the turbo, while the turbo feels like I've worked harder. Very weird.