Interval training is the heart and soul of conditioning for boxing. Boxing itself is composed of intervals, short bursts of speed throughout three minute rounds spread out among long arduous workouts. It makes sense that if you want to be a top boxer, meaning you want to have the conditioning and skills to hang with the best, you must incorporate intervals into your training.
My favorites are 3 mins of intense with a 1 min break (heart rate at around 80-85% max), 400m sprints at 90% effort with a minute break, 30 sec full speed sprints with 30 sec off doing shuttle runs in a tennis court, and i love doing Tabata sets (sprints and heavy bag punch outs). Nevertheless, how to proceed is fairly simple, hard part is to get on the market consistently and just doing it. Two common mistakes that boxers make, I included at times previously, not thinking long-term regarding your intervals instead of understanding their purpose.
Your intervals are not only to prepare you for an upcoming fight, like Mayweather vs Pacquiao they may be preparing you for further training. Once you train today, you will be practicing for the workouts of tomorrow, and next week, and next year, your ultimate goal is to be the ideal boxer you may be, and that doesn't happen overnight irrespective of what your interval program. Every workout should enhance the bar by 1 inch, that's how you will need to take into consideration your training. You are not training today to fight tomorrow. If you train like that you'll burn out fast. Rather, you are training now to train better tomorrow and to become your best come fight time, only to return to training and also be much better for the upcoming fight. It's very easy to lose give attention to this perspective and rush, the secret is to imagine in yourself, trust your motivation, and trust your commitment as well as your desire. If you trust in those you have nothing to worry about, you can relinquish the pressure of 'now' to your benefit.