Easy roadwork
The bulk of your running. Conversational pace, low intensity, built for aerobic base and recovery. Most fighters run these too hard, which is why they show up flat to sparring.
Running is the oldest part of boxing training and the part most people program worst — too hard on easy days, too little structure on hard ones. Log every run and see it against the work you're already doing in the gym.
"Going for a run" isn't a training prescription. Each of these does something different, and running them all at the same intensity is why most fighters get less out of roadwork than they should.
The bulk of your running. Conversational pace, low intensity, built for aerobic base and recovery. Most fighters run these too hard, which is why they show up flat to sparring.
Work bouts that match round length — three minutes hard, one minute easy — so the adaptation transfers to what you actually do. This is the run that makes round three feel different.
Sustained, uncomfortable but controlled. Builds the ability to hold a high output without tipping over. One a week is usually plenty during camp.
Short and genuinely slow, the day after hard sparring. Its job is blood flow, not fitness. If it leaves you tired, it wasn't a recovery run.
Log the run, see the trend, and know whether your conditioning is actually building or just accumulating.