Boxers need to train with Weights.

Despite the research and advancements in science, for a long time, many boxers refused to train with weights. In the last decade, however, the United States Amateur Boxing Association and boxing professionals have taken note of the progress that European boxers have made with weight training. Now most well known professional fighters regularly workout with weights. After all, in a match where two fighters are equally skilled, the stronger fighter will win.

Not too long ago, it was thought that weight training would make a boxer slower, less flexible, and more prone to fatigue. Many also considered weights to be an unnecessary addition to a boxer's already grueling physical schedule. But in recent years, science has shown that a properly designed weight routine will increase boxers' speed, flexibility, and endurance, and is an integral part of bout preparation

A boxer should train with weights two to three times a week. Any more than that, and the weight training could interfere with the sport-specific training - sparring, bag work, cardio - and a strong fighter without properly developed skill is no fighter at all. It's also important to avoid weight training on sparring days, as you'll need you're strength in the ring to develop your skill. It's recommended too, that boxers halt their weight training at least one week before a bout. Save your strength for the fight.

Boxing workouts should differ from other types of weight training because strength and power - or "explosiveness" - are what the boxer aims to develop. With that in mind, as you train, remember to use quick, explosive movements during all the exercises. If your speed is top-notch, but you need to develop more strength, do lower reps with higher weight - work in the 4-8 rep range. If your strength is good, and you want to maintain it while adding some speed, work in the 8-12 rep range with moderate weight.

Also, remember that a boxer's training, unlike that of the bodybuilder, is for the purpose of function, not size. Therefore, stay aware of your body weight. You don't want to put on so much muscle that you out-size your weight class. This workout is designed to keep function the priority, by utilizing compound power movements. Try it out, and you'll fight better, guaranteed.
Barbell Snatches
Dumbbell Bench Press
Power Cleans
Dumbbell Lunges