Boxing is a sport that is intermittent in nature, characterized by intervals of explosive bursts of power mixed with scaled down survival movements; therefore, training intensity should be similar to a competitive fight sequence. After all, you will not be constantly throwing explosive punches throughout a three-minute round--no human can sustain that intensity level--nor will you be in a survival mode for the duration.
Some Science-
In an Olympic boxing match, boxers must fight for a total of 11 minutes. The fight is structured for three three-minute rounds with a one-minute rest between each round. Therefore, it makes logical sense for a boxing athlete to have a high anaerobic threshold level and aerobic power level to meet the demands of this sport. In 2002, Laura Guidetti conducted a boxing study for the relationship between ranking in boxing competition performance and some physiological factors. The data suggest there were two basic factors related to boxing performance: physical fitness as indicated by individual anaerobic threshold and maximal oxygen consumption and upper-body muscular strength.
Time Frame
According to Tudor Bompa, author of "Theory of Methodology of Training," "32-36 weeks or 200 days of training are needed to reach a peak for advanced athletes." A form of periodization training is needed to peak at the right time for a fight. There are two basic stages of training: general preparation--containing a strength endurance phase and a basic strength phase, and the competition phase--emphasis placed on power and speed.
Getting My fighter stronger-
Early in the training cycle, structural--multijoint--exercises should be integrated into your workout twice a week. Squats, dead-lifts and power/hang cleans utilized to strengthen the hips and legs; after all, your punching power comes from the ground up. T-bar rows and wide/close grip pull-ups included to build back strength--large muscle area that aids in delivering a blow. High incline benches and shoulder presses to develop the deltoids for extending the crisp snap of a jab or straight right/left. Allow two minutes of rest between sets for maximum strength development.
Build Power-
High speed, sport specific power exercises should be performed three times a week, including: heavy bag, speed bag, double-end bag and jump rope with high/moderate interval intensity of 40/20 seconds per minute. These should be sustained throughout three three-minute rounds. As a changeup, similar interval training in shadow boxing with light weights, medicine ball exercise, and hitting mitts with trainer. Light-sparring and two-mile interval sprints performed once every four days. Allow one day off a week to avoid overtraining.
Fight Prep-
Intensity and speed pick up significantly. Combination lifts--clean and jerk, replace strength lifts--squat, dead-lift. Push up variations--clap, medicine ball--replace incline press. Amp up intensity during bag intervals with high/moderate intensity at 45/15 seconds per minute. More boxing specific exercises, including longer and harder sparring sessions. Plyometrics--depth jumps, multiple box jumps, bounding and medicine ball ballistic training--should be done early in this phase once every three days. Interval sprints and agility drills every three days.