Any boxer who's ever stepped into the ring for sparring or competition knows the feeling of fatigue. Your breathing is labored, your feet feel stuck in cement and throwing punches seems impossible. When you've reached this point, your best course of action is to hang on until the end of the round. If you don't want to experience this feeling again, your endurance training needs to begin long before you square off with an opponent in the ring.
Devote time to roadwork several days per week. Roadwork is a boxing-specific term that describes running as a method of improving your cardiovascular endurance. Without strong cardio, you'll quickly get tired during competition. Trainers often have varied approaches concerning this form of conditioning. Some trainers recommend long-distance running at a moderate pace, while others advise intervals of slow running and sprinting. Even taking a generic approach of running for 30 minutes per day, five days per week can gradually build your endurance.
Perform boxing drills such as hitting the heavy bag, speed bag, double-end bag and focus pads at an elevated tempo to build your endurance. Use these drills for three minutes per round, which is the standard round length in boxing. Although each of these training methods helps you build a specific set of skills, each also contributes to better endurance to help you avoid fatigue during a match.
Train frequently to improve your skills and self-confidence. Novice boxers quickly lose their energy when they're nervous in the ring. Being nervous often leads you to tighten your muscles and hold your breath, which quickly drains your energy. Confidence comes through developing your skills. When you fight, you should be relaxed and focused; this attitude doesn't happen overnight, but is rather the result of months of training and even some light, technical sparring with a trainer to get you used to the feeling of being hit.
Build your stamina in the ring by practicing sparring in 60-second rounds. Over time, you can work up to two-minute rounds and, eventually, three-minute rounds. This approach helps you gauge your exertion so you use your energy during the round but don't get too fatigued.