First of all, doing mental activities is beneficial. When we read or play puzzles, our brain still work at lower capacity in comparison with normal status. It means that the mind in leisure and working time is not much significantly different. Hence, we can remain our adaptation to working pressure despite of the fact that we are free quite a while.
Nevertheless, a great number of people long for their brain to relax thoroughly. In weekdays, they spend eight hours per day to work and the pressure of job makes them exhausted. They are bored with mental activities as their brain are stimulated continuously for job so they need something which is really discrepant even contrast.
From personal thesis, I think that no way outstrips other due to two ways are appropriate for various circumstances. Like for instance, if I have to do enormous workload in office hours, I will likely choose the second way to spend my leisure time. On the other hand, providing that my job is not much uptight, I may challenge my friend to play puzzle or find a peaceful place read some books.