How is your cardio training coming along? I missed the original topic but here's my 2.0 anyway. I like to develop a base level of cardio that lets me keep going at a rate of 70-80% of my heart rate reserve (around 150-160bpm) for 1.5-2x the duration of the fight. This includes rest periods. Example: I'm fighting 5 x 2-minute rounds. That's 10 minutes. Add in 1 minute of rest between rounds 1-2, 2-3, 3-4 and 4-5, and that's 14 minutes of activity. I usually double this, so I would aim for being able to keep my heart rate as mentioned above for around 28 minutes so that it's at least comfortable. This is just the starting point. To simulate the anaerobic nature of the fight, I would then raise my heart rate to 80-90% of my heart rate reserve (160-170bpm) for 2 minutes, bringing it back down to around 70% for 1 minute. I usually do this for the number of rounds I'll be fighting, plus 1 or 2 extra for good measure.