BJJ is an insane cardio workout while also being tons of fun. Good combo, there. To quote Robert California from the office "Trust me, one nine minute bout is the cardiovascular equivalent of running uphill for three hours. I could go to the gym three times a week, or I could wrestle Stu once a month." He's talking about wrestling there, but I think it applies to bjj as well.Thanks for the kind responses, and thanks for the videos dunc! There were probably a hundred tiny things happening in that match that that would totally go unnoticed for unfamiliar guys like me. I'll be sure to show videos like that to my kids once they get more experience.
On another note, I think my son is starting to feel the benefits of attending BJJ classes. He appears less "chubby" compared to before BJJ and my Wife and I commented that he looked good, surprised at how the change occurred rather quickly. His swimming instructor, who only meets once a week, was also surprised that his speed and stamina improved significantly seemingly out of nowhere.
Well, it's still very much the early stages, we'll have to wait and see how things go over the next several months.
Thanks everybody!