I had the opportunity to go to the gym this morning (and it's looking like I may get a lot more of those opportunities) and do some grappling training with some of the boys. I'm rusty, but it was a good time. The lads with whom I was training were enthusiastic but not real experienced, so I just ended up staying on the mat, rotating guys in every two minutes. I learned a long time ago, that I'm pretty much responsible for training myself regardless of whether I'm the instructor or the student. So when there's a clear ability/experience gap, I try to put myself in the most vulnerable positions I can and then work through it. It takes a while to put ego aside and learn that "if you're not tapping, you're not training." With the guys today, I was coaching them along, trying to get them to polish their fundamentals. "Slow is smooth, smooth is fast" is an easy mantra to verbalize, harder to internalize.
After a couple of hours, I was the only guy that wasn't huffing and puffing and blown out, wind-wise. Part of it is just experience, and learning to relax during randori. When I made a jump in training from grappling-pure (Judo/Jiu-Jits) to MMA, I learned that I needed to achieve a whole new level of fitness, and I had to re-learn how to relax and breath. It is of note, though, because I really don't "train cardio."
I hate running. Running is da devil. Unfortunately, the Army is enamored of running its ass off, so I get to do it whether I like it or not. Fortunately, I'm usually in a job where I can dictate my own PT and as long as I excel at my PT test every six months, I'm left alone. And, I do do well on my run times. To paraphrase from Quigley Down Under, just because I say I have no use for running, doesn't mean I can't run. So, being that I get graded twice a year on my two mile run, in a good year I'll usually run a grand total of...four miles. I'm a big fan of sprint workouts, but don't count sprinting in my run totals.
Living so far south, in a tropical zone, even if I did want to run I'd only be able to early, early in the morning (when I should be at the DoJo) or late, late in the evening (when I should either be at the DoJo or drinking beer). There are other forms of "cardio" that I do enjoy, although my main goal is pursuit of a decent workout, not aerobic excellence. I'm a big fan of swimming, and all the canals and big blue open water around my house offers plenty of opportunity for both raw swimming and finning. Mongo's #1 Wife has started giving me grief about it though, ever since "Elvis the Crocodile" started making appearances in the canal.
I enjoy swimming, I don't love swimming. To each his own: while I can never, ever imagine getting up at 0330 in order to drive three hours to participate in a Triathlon (You want me to run, swim, and bike? Which circle of hell am I in?) I would and have done the 0330 wake-up to get into a decent fight.
The point of all this is just to posit that I think a lot of people mistake cardio/aerobic fitness for breathing discipline and the ability to employ relaxation techniques while under duress. Baseline aerobic fitness is pretty easy to achieve. If you can run linearly for hours without getting winded, that's great. But if you can do that but can't go two minutes on the mat, or diverge through some obstacles or hurdles without losing your rhythm and getting out of breath, you might want to expand your "wind training" beyond aerobic road work.