Physical fitness involves your own awareness of your physical condition. It is not unusual for a competition to last from 8 to 12 hours in one day with additional hours in another day. Some tournaments are several days long with some intervening days with no bouting at all. Most of your attention to physical fitness should occur prior to the tournament. Several days of a good diet prior to the tournament is a good idea.
Many fencers support the idea of carbing-out the day before competition begins.
Although fencers are prone to party and mingle with the natives at a tournament venue, common sense dictates getting a good night's sleep prior to the day of competition. Taking care of your body during the competition is also very important. Often times there is a long waiting period between your bouts. It's very easy to become overheated during and shortly after a bout. Invest in a set of sweats or warm-ups that will keep your body heat in and cool you down slowly.