I've always wanted to try those weight vests. I figured I'd last about three minutes of intensive training.
Who here has naturally good cardio. You get a big sob comment from me then, cuz my conditioning has always been like well...prolly better than Matt Serra's brother. Nothing is worse than that...lolz!
I have pretty good cardio at the moment and I smoke bud every day and haven't trained vigorously since Thailand, just sparring and shadow because my heavy bag finally gave in.
I do go on 20-30km nature hikes pretty often aswell though and altitude is good for lung capacity.
I am lucky to be able to get super fit really quickly, like when I first went to Thailand on the most recent trip I was in poor condition and threw up during my first two sessions of hard sparring/clinch work, but after those two I was good to go.
I think you have to train pretty hard to be able to do that though, I push myself and I think mental strength is probably the biggest factor in terms of improving cardio. That inability to quit forces you to swim, sinking is no longer an option.