If a person works as a mover or digger having a lot of physical activity, he becomes tired and dreams about making money by sitting in the chair, looking at computer and talking to other employees.
If a person sits in the chair all the day, looking at computer, he early or later becomes sad and tired, dreaming of physical activity.
Why do we pay for fitness? Why just dont we get 2 jobs? One in office and one simple manual. We can split them today whatever way we want: half of a day, 2 days a week etc.