Adarq.org

"In the classical Minnesota experiment, young men with a maintenance requirement of 14.6MJ/d were restricted to 6.6 MJ/d for 24 weeks.9 They reached energy balance at the end of the experiment, with 58% of the total energy saving being ascribed to a reduction of activity- induced energy expenditure; of this total energy saving, 40% was due to reduced body weight and 60% was due to reduced physical activity."
Sf the total reduction in energy expenditure, nearly 60% of it was due to less calories burned during exercise of which 40% was due to being lighter and 60% was doing less total activity. That means that most of the adaptive component isn't even in metabolic rate in the first place.
It's changes in energy expenditure during activity, both formal exercise and SPA/NEAT