Before you start about a nice work out at the gym, and you didn't know Victorians cared for the health of their prisoners, know that this "activity" went on all day (for about six hours at a time), every day, not as "recreation," but as punishment intended to cause pain, suffering, and despair. On the typical prison diet with this kind of hard labor, inmates mostly died in prison long before serving out their sentence.
The term "tightening the screws" means that sometimes we make it more difficult for others for no other purpose than because we can. As if anyone needs life to be harder, it seems some folks exist to do just that. There's no judgment here, just a suggestion that if Christ's coming means anything, it's time to lighten up, loosen up, and cut others in our lives some slack.
Loosen the screws with the purpose of making life a little easier for someone else. And maybe start with giving yourself this gift.