How many calories burnt at 200watts/hour

by chinchli   July 15, 2014  

By my understanding, the general rule of thumb is, on a moderate to hard ride you will burn 600-1000 calories (depending on weight, effort etc)

I've just done a 1 hour turbo session where I averaged approx 200W. According to the bastion of truth Strava, this means I burned 651 kJ. Various unit convertors on the interwebs tell me this is 155 calories.

So, my question is, where did all the other calories go? Did I really only burn 155 calories on what felt like a pretty hard interval session?

Thanks

4 user comments

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Your conversion doesn't take into account human metabolic efficiency, around 22-26% (most places quote 24% as the middle ground, I've seen a few sources saying 18-30).
So kCal (burned)=[(kJ/4.2)/0.24)].
In your case it's 645 kCal.

glynr36's picture

posted by glynr36 [390 posts]
15th July 2014 - 19:14

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As above... in loose terms, you can simply swap Kj with Kcals to estimate your calorific burn.

An hour at 200w for 650 watts burnt seems about right to me.

posted by Jimmy Ray Will [279 posts]
16th July 2014 - 15:18

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Jimmy Ray Will wrote:
As above... in loose terms, you can simply swap Kj with Kcals to estimate your calorific burn.

An hour at 200w for 650 watts burnt seems about right to me.

Why didn't I just put it like that ha!

glynr36's picture

posted by glynr36 [390 posts]
16th July 2014 - 15:45

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Good effort... For a bit of perspective, in his book "faster", Michael Hutchinson says he burns 1400 kCal in an hour at 25 mile TT pace, and that's still not enough to beat Wiggo!

posted by benezeir [55 posts]
16th July 2014 - 22:54

1 Like