Earlier quoted context omitted.
Nitpick: "high intensity cardio" is kind of an oxymoron. "Cardio" is used to mean training which mainly uses the aerobic system. That is, longer term, lower intensity, training that you can sustain over a long period of time because you are going at a pace that your body can turn carbohydrates into all the energy you need. Sprinting is anaerobic training, as is most strength training. It's high intensity, you can't s…
It won't increase your aerobic capacity... It will raise your lactate threshold. The only way to increase your aerobic capacity is to spend a large amount of time exercising at an aerobic heart rate.
When I train jiu-jitsu, I do several rounds of live rolling. Usually something like 4 6-minute rounds with a minute rest inbetween. The hard part of live rolling is the anaerobic part: quick spurts of high intensity. How fast you can recover from them, and how often you can sustain doing them over time determines how well, athletically, you will do. But this is also a 30 minute period with an elevated heart-rate, and you never are fully rested inbetween your anaerobic bursts. So, it is also an aerobic workout.
Despite not doing much explicit cardio training, I still have the cardio capacity to run decent distances with decent times, on the rare occasions I do. That's because I am training my aerobic system even though most of the exercises are anaerobic. (I once went on a 9 mile run having not gone on a run in over 6 months, having only done jiu-jitsu training and conditioning during that time. My lungs were fine. My legs were not.)