(1)A convicted inmate sentenced to rigorous imprisonment shall, and a convicted inmate sentenced to simple imprisonment or an undertrial inmate, if and as long as he so desires, may be engaged in work, which shall not be of an afflictive, degrading or humiliating nature, and which shall, so far as may be practicable, especially in the case of a convicted inmate sentenced to imprisonment for a relatively long term, be in the form of such vocational training as will maintain or increase his ability to earn a living after release.
