Office workers spend much of their free time jogging, going to the gym, doing yoga, going to whole foods, and obsessing about the food they eat in ways that blue collar worker don't.
When did all of this happen? It seems like young single urban office workers don't fit in with any community and so they're obsessed with these things as a substitute.
Ina Zweiniger-Bargielowska argues that this happened in the first half of the 20th century, and can be read as a kind of primitivist response to white-collar capitalism. The argument of many advocates of "reducing culture" was that modern "civilization" had produced male bodies that were unfit due to their sedentary nature. As such, scientific, medicalized schemes to promote fitness were deemed necessary.