The sedentary office lifestyle is genuinely disastrous for your health, both mental and physical. It's especially insidious owing to the fact that the effects are largely invisible, just massively increasing your risk of heart disease, stroke, and cancer. That's not to say that the other extreme of constant manual labor isn't also disastrous for your health, just that I don't think the health effects of a sedentary lifestyle are taken seriously enough by institutions and people in general.