Isn't it a bit ineffective to do 100 sits or 100 push ups everyday? I mean you should rest your body in between workouts.
I think the given routine is quite questionable. A beginner is perhaps not able to do the 100 situps per day, and if he reaches the point of doing 100 reps easily, there are probably better/more helpful exercises.
Also I noticed the routine does not state how many reps a set should have. Does one make 100 situps in a row, or just 50 / 25 / n?
When reading the manga the first time, I understood this routine as motivation. I mean, every healthy person should be able to do this routine after an appropriate amount of practice. While not becoming a oneshotting monster-hunting hero, one will perhaps get in shape. Also one can scale this down very well. For example to 1/10 of the reps and km.