Yes, I saw that metric, and my point stands. Cars are more efficient than humans, even humans on bikes. > note that maintaining internal homeostasis in a human

Yes, I saw that metric, and my point stands. Cars are more efficient than humans, even humans on bikes. > note that maintaining internal homeostasis in a human is not exactly "losing" energy to heat If you bike a lot you will eat more. People tend to forget that and assuming the biking is "free" energy. I guess if it's just a causal activity then it is, but if you do it to commute you will end up eating more.