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As in, one that will calculate the calories used for a set amount of an activity? I've been using the first ones that come up on Google (like the one linked below) but they do seem to come up with pretty high numbers. Is this accurate, or are they flattering you in the hope that you'll come back to their web site or app? For example, the website below came up with 2,050 calories (as in kcal) for a 40 mile bike ride. Surely that's too many!
https://runbundle.com/tools/cycling/cycling-calorie-calculator
Depends on many factors though - high intensity for that distance will burn more calories...did you track your heart rate at same time? That should help provide a more accurate burn as well.
I think for anything to be vaguely accurate it needs to be based on weight, and heart rate/level, or power,never mind gradient, surface, wind etc.
I'm much heavier than I should be, so any hilly rides I will work a lot harder burn a hell of a lot more than a racing snake. Distance or time on their own are not a lot of use, so many other variables.
I'd assume outside of a lab, a power meter, hrm and your weight etc would give about as accurate as you'd get. As for apps I don't know.
It depends how 'hard' the ride is for you too, I guess.
If you have an HRM or power meter, Strava factors that into it's calculations.. in the past month I've done 2 rides which it calculated were 3800 calories - a 160km gravel ride with mellow hills and a 30km MTB ride with steep ones.
I'd still take any calculations with a pinch of salt though.. maybe better to treat them as relative rather than actual.
Power meters on bikes give Calories burnt.
My 4iiii reckons I burned ~2100 this afternoon on a 3hr10min ride, 54 miles with 3000 feet climbing, averaged 181W and I was just under 82Kg when I left home.
Power meters on bikes give Calories burnt
They'll maybe tell you the amount of work you performed. They won't tell you the calories you used to do it.
They’ll maybe tell you the amount of work you performed. They won’t tell you the calories you used to do it.
They do, and it's by far the most accurate way of measuring it outside a lab. The maths is quite nice and simple too as there's 4.1 joules in a calorie, and the body burns almost exactly that to produce 1 joule of work (I.e. it's about 25% efficient, and that doesn't alter much between individuals). So if you output 200W for 5seconds you've burnt a calorie (well a kcalorie, which is what food is measured in).
Strava should be the best of the rest as it's making an estimate of power output based on what it knows about you and the route you took (and it also has a lot of data from other users power meters to validate it's estimate against).
Alternative oppinion:
It doesn't matter. Take a stab in the dark and say 500cal/hour, plus or minus 20% for effort levels. If at the end of the week/fortnight/month your calories in Vs out maths doesn't agree with the scales then make an adjustment. But it doesn't need to be to the outputs, you can just tweek the inputs as long as the ammount of exercise is consistent.
Tinas I think the point was the energy burned will be a number greater than the work done. You’d need to divide the work by the efficiency of the body and that isn’t really a number that you can know.
Tinas I think the point was the energy burned will be a number greater than the work done. You’d need to divide the work by the efficiency of the body and that isn’t really a number that you can know.
It's a factor of 4, it's fairly well known.
There really is a lot of variables- braking, tyres, surface, wind, aero position etc.
For some examples with calories computed from a power meter ( with 86kg rider):
Road bike (Giant TCR):
68km/1,217m road ride @20.1km/h : 3,202 kcal
153km/1,155m road ride @25.0km/h : 3,564 kcal
163km/1,252m road ride @27.7km/h : 5,859 kcal
Gravel bike (Cannondale slate):
100km/860m road ride @20km/h : 2,209 kcal
120km/737m (80% off road) @22km/h : 3,234 kcal
88km/2025m (35% off road) @15.0km/h : 3,474 kcal
167km/1,068m (40% off road) @22.7km/h : 4,212 kcal
Mountain bike (Cotic solaris):
23km/200m @15.4km/h : 1,176 kcal
43km/330m @18.2km/h : 1,317 kcal
41km/845m @13.3km/h : 3,166 kcal
Power meter obviously only knows what effort you are putting into the pedals too - an hour on road is far easier than an hour off road on the upper body etc - not sure if anyone has ever quantified that though?
On the gravel bike Strava regularly over estimates (compared to my PM) my riding buddies calorie usage by 10-20% compared with me (similar weight/bikes etc) he doesn't use PM or HR monitor.
Thanks all, I guess the estimates are in the right ball park for the unfit old man that I am!