People who are working and studies hard need to have a free time from the stress of their work. Some people prefer to use this time to do some work which help them to improve their mind, while other people prefer to relax. As I see it depends on the person. If they are hard working, they need time to relax or if they have less work, they need to do something which helps them use their mind.
Some people prefer to use the free time, to do something active because they do a sitting job and they stay the whole day sitting in the chair and at the end of their work time they have back problems and the body feels tired because they not moving. These people need to go to the gym and do something which let them move their body.
On the other hand, people who have physically demanding job such, doctors and teachers need to relax because most time they working hard and moving a lot during their work. One more plus for them to relax in your time, is that you can stay with you family, also to look after you children if you married.
To summarize, the main point for all people is that they want to have a health body even if they hard working or just sitting. I suggest for everyone to do what is good for their health. The busy person need to relax their mind and do some exercises.