I know this is stupid, but I'm wondering of ways i can increase my cardio during class or work. Some ideas I had were taking deep breaths and holding them for a little bit. Not to actaully increase my cardio strength but maybe to increase my lung capacity. Do you think increasing lung capacity would translate into lasting longer without gassing during my training? Any ideas are appreciated. I train two 2 hours sessions a week and i'm usually dead by the last 3/4 of the training. I want to be able to push it out the end. Just want to maximiize my workout instead of slacking when i'm hitting the bag or rolling with someone.