It sounds like one of those modern myths—that, or an old Sex and the City episode buried somewhere in our collective cultural subconscious.
How many songs have you begun to hate because of the gym? If you make permanent changes, you get permanent results.
While the glasses can monitor tiredness in real time, there's no kind of useful feedback for this feature just yet.
Who said that it has to be healthy? The gym does have its social component and that is fine.
What is it that turns so many sweaty kettle bell classes into afternoon assignations, so many stretching sessions into slippery slopes? Fitness boot camps are a heart-pounding way to boost your fitness level.
My terrible posture is a chronic habit, and having a robotic personal trainer tell me that I'm screwing up is a pretty good way to keep myself in check.