How realistic is kj = cal for most people?


#1

I know that there is a difference in efficiency between different people but was wondering if there’s any stats on how many people fall into the most efficient category where 1 kj of work really is a single calorie.

Are all athletes doing a couple of hundred hours a year of training in that category as they’re becoming more efficient, or are even trained athletes still variable in the differences between them?

Some other questions that I’ve had floating around upstairs for a while:

If you take a trained athlete and make them gain 5 kilos, are they still as efficient? What if it was 5kg of pure fat, or pure muscle?

Why do my rides on Strava or Wahoo sometimes say my calories are less than my stated kj?

What is the greatest difference between the most efficient and least efficient person in producing a kj of work?


#2

No differences in cycling efficiency between world-class and recreational cyclists.

L Moseley, J Achten, JC Martin, AE Jeukendrup
International journal of sports medicine 25 (5), 374-379


#3

Thanks sryke,

I think that’s looking at pedalling and biomechanical efficiency. I should have been more clear, I’m thinking about the body’s efficiency at converting food into energy which results in the 1=1 equation.


#4

Please take a closer look at the paper. Cadence was kept constant for the GME tests.

You are asking about the variation of Gross Metabolic Efficiency. This study looked at this variation for different populations, e.g. athlete levels, across different power outputs.

HOwever, it should be noted that several factors impact GME but variation is not that huge.