Well, it’s not wrong. Efficiency is really just a measure of how much work it takes to achieve some result. If your unit of work is “exercise” and your end resu

Well, it’s not wrong. Efficiency is really just a measure of how much work it takes to achieve some result. If your unit of work is “exercise” and your end result is “burning calories”, then clearly a body which takes more exercise to burn the same number of calories is less efficient at achieving that result!