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Comment by balfirevic

3 years ago

> A few hours on my bike can be 2,000-3,000 additional calories over base metabolic rate.

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

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...

  • > 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.