Re:Scientist busts myths about how humans burn calories
by nkurz on Friday February 18, 2022 @08:50AM
(#30385616)
You are forgetting that the human body is nowhere near 100% efficient at burning fuel to put power into a pedal. To produce 400 watts of mechanical power, the body consumes about 4 times that amount of fuel (25% efficiency). Consuming 2000 kcal over 3 hours is thus closer to the more realistic 200W of power to the pedals, and even the higher ranges make sense if he's a good athlete. See this article: https://www.welovecycling.com/wide/2020/05/14/how-to-convert...
Re:Scientist busts myths about how humans burn calories
by balfirevic on Friday February 18, 2022 @09:15AM
(#30385894)
> You are forgetting that the human body is nowhere near 100% efficient at burning fuel to put power into a pedal.
I'm not, because the parent poster explicitly said "That's not based on made-up calories but actual work from a power meter on the bike."
Which seems absurd, hence my comment.
Are you sure? 2000 kcal in 3 hours is 770 watts of power output.
Edit: Wikipedia [0] says "During a bicycle race, an elite cyclist can produce close to 400 watts of mechanical power over an hour and in short bursts over double that - 1000 to 1100 watts; modern racing bicycles have greater than 95% mechanical efficiency. An adult of good fitness is more likely to average between 50 and 150 watts for an hour of vigorous exercise."
[0] - https://en.wikipedia.org/wiki/Human_power