1. According to the research of the police friends of the U.S. imperialists, there are quite a lot of sports equipment in the prison, with the purpose of guiding male prisoners to be aggressive. Therefore, it is not true that the fitness mode of prisoners in prison is purely unarmed.

2. In the case of zero load, the muscle strength growth is slower than only one part of the equipment training, but the sense of balance and coordination will be significantly improved. This is my personal comparative feeling.

3. After personal experience, I think the direct value of prisoner's fitness lies in exercising the coordination ability and effective sense of balance of multiple muscle groups. Many actions can save lives at critical times, such as pull-ups for climbing and push-ups for throwing.

4. But if you want to build big muscles, it's not enough to simply count on unarmed gymnastics. In addition, stone plates, stone locks, stone hammers, metal weights and military gymnastics have existed since ancient times. Without these things, the ancient Greeks developed muscles with their bare hands, which is untenable.

Finally, what I can accept is the tough concept of "every place is a training ground" and "training available strength" However, it is a rigid dogmatic bodybuilding to completely copy the methods and advances in the book, regardless of its own situation and surrounding conditions.