I looked through the faq and didnt see anything about this. Basically I've been doing Judo for a little while now plus weight training, my cardio isnt good but I'm not a bum who never gets any form of cardio at all. Anyway I wonder if I do liss how long before I can do interval type stuff. Or could I just go straight into fartlek training and build from there without the 40 minute type stuff? Sorry if this has been covered already.