Luke regretted getting detention- his dad wasn't a parent who used abusive tactics to get a point across. He made Luke run laps in his large back yard til a rut was made in the grass then had him do many exercises like push-ups, sit ups, jumping jacks, jump rope, sprints, and more, until Luke could barely stand. Then he would leave Luke to drag himself to his room or to the bathroom to do whatever. Luke was happy that they had a one story house at this time- he wouldn't have had had the energy to crawl up a flight of stairs.
It was cruel in the beginning, at least to Luke, but over the last few years, Luke came to an understanding- some actions come with consequences, and no matter how great those consequences are, you have to face them all... But he still would swear at his dad the following morning- or evening if this happened in the morning- until his throat hurt. It was their compromise...seems to have had worked since Luke was 11 so they go with it.