The authors want to establish the conclusion: > a long-term increase in activity does not directly translate into an increase in total energy expenditure But

The authors want to establish the conclusion: > a long-term increase in activity does not directly translate into an increase in total energy expenditure But they argue from a correlational study. This cannot establish that an intervention to increase activity would not lead to an increase in energy expenditure. Something like the Lucas Critique[1] applies to the human body and any adaptive system: once you make an intervention, the system might adapt in ways that don’t reflect correlational data from before the intervention. [1] https://en.m.wikipedia.org/wiki/Lucas_critique https://en.m.wikipedia.org/wiki/Lucas_critique