its true, and I dont agree with the policy.
the argument is they are bigger and stronger and harder to deal with..., but I mean come on they have batons, shields, pepper spray, tasers at their disposal, I think they have things covered.
lifting weights allows people to release pent up energy or aggression, is good for your health, helps pass the time, and they exhaust themselves in the process, therefore making for a more subdued inmate, you can also use access to weights as a privilege to gain more leverage over the inmate, so if they are acting up, they dont get to lift etc....
just my opinion