i believe who ask is in the early stages of the game where one punch fulls half the pain bar. so two punches knocks you out.
the best you can do early in the game is pay Baily the first week, only 100 quid, then try to gain pain resistance for two weeks and the second week refuse to fight (even if you lose the first punisment job is not that hard, the second one or the thired one is really bad as you get to live with Eden...), keep wining resistance to pain and alternate pay and fight. the thing is to only only fight Baily, once you build enough pain resistance you can fight Baily and the goons like Madchef said. However! unless you sleep at the farm (doing the very looooong farm side quest to mange to do that) Baily will wore you at night all the week you fight and defeat to get her money from you by being your pimp.