If you've got a fight coming up, you're probably wondering what kind of program you should follow when training for a fight. In this article I'll keep it real simple because given the nature of MMA, it is really easy to get confused and have analysis paralysis.
Assuming you are already in decent shape and are satisfied with your level of strength and skill at the time and you just want to work on your overall conditioning so you don't gas out halfway (or worse) through the fight, here is a simple formula to follow: mimic the fight as closely as you can in your training.
You see, one of the biggest factors that MMA fighters get confused about when training for a fight is what type of conditioning to do. But it's actually quite simple. Long ago studies have suggested that the best way to condition for an event is repetition of the performance of the event. In other words, if you are training for a fight that is set to go for 3 five minute rounds, then the best way to condition prior to the fight is to spar for 3 five minute rounds as much as you can!
Let me explain this in another way that will help you understand this further. Let's say you go running 3 miles a day, five times a week for a month. Your aerobic endurance (or wind) will be in decent shape. Now, let's say you try to go swim 20 laps in an Olympic pool, how do you think your conditioning will transfer? Sure, you'll do a heck of a lot better then some couch potato, but you'll still be breathing hard and fatigue fairly quickly.
Why? The human body loves to adapt and get comfortable with movements it finds itself repeating a lot. As soon as it gets comfortable a lot of your body's functions go on "autopilot" which makes it easier to function, allowing you to perform the movement with more ease, causing you less fatigue. Whenever you perform a new type of movement, your body has to "wake up" again and focus on coordinating movements it isn't familiar with, and this causes you to fatigue faster.
So let's go back to training for a fight. You can run, jump rope, swim, and bicycle until you're confident to compete in a marathon, but if you don't do a lot fight specific conditioning, such as sparring or conditioning for 5 minute rounds with 1 minute rests in between, you're still not being as efficient and effective when training for a fight.
So when training for a fight, the closer the fight gets, the more your conditioning should mimic the actual fight. Sparring will obviously be your best friend, but you can also switch up other conditioning exercises to mimic the time in a round and rest period (running as hard as you can for five minutes, circuit training with or without weights for five minute rounds, etc).