[citation needed] Boxing, like several other fighting sports, categorizes its competitors into weight classes.In extreme cases, a fighter may forgo solid food before the official weigh-in ceremony, and eat a lot afterward to compensate.In some very extreme cases, boxers have been forced to stop eating solid food up to three days before the weigh-in ceremony, in order to make weight for the fight.Sometimes, if a boxer doesn't make the weight agreed for on the first weight-in, they might go to a sauna or to jog with a jacket to sweat and lose the extra pounds, however this is mainly water that the body holds.Sparring partners sometimes agree to practice particular types of punches or defense moves to focus their training.