In case you wondered …

… Why too much gym can be bad for your love life - Telegraph.

A study out this week, though, may release a few gym bunnies back into the world. For it revealed that people who rely on working out to shift excess pounds could well be toiling in vain. It would seem the body adapts to new, more energetic regimes and quite swiftly changes metabolism, meaning fewer calories are burned off. After a couple of months, gym rats reach a plateau, after which it’s hard to shift further flab. This corresponds with Pontzer’s research on Tanzanian hunter-gatherers, which demonstrated that they didn’t expend far more energy in their wanderings than Western couch potatoes. And of the 300 subjects monitored in the New York study, those with moderate activity levels (ie, those who walked to work and used stairs, rather than lifts) were found to use most calories.