I'm watching UFC primetime right now and as apart of Bj Penn's cardio training he swims down to the bottom of a lagoon, picks up a rock and sprints with it along the bottom of the lagoon. Now we all know sparring is mainly an anareobic activity. So is this good training? Surely swimming underwater is about as aneoroib as you can get, since you get no oxygen. Obviously most of us dont have lagoons, but I was thinking of swimming lengths of my local pool under water. I saw Wanderlei Silva doing some trainig similar to BJs where he would pick weights from the bottom of a deep pool. On the negative side I thought it is not very specific to sparring as we still breathe while throwing combinations etc. So what do people think, anyone with some good training knowledge help me out on wether this is an efficient way to train?