Yeah man, after 2 months I still gas out occasionally on the warm-ups (and when rolling) although it has been getting much better. I am still pretty damn worn out immediately afterwards even if I don't completely gas out. I am a bigger guy (I range from 200-215) I am slightly overweight with a nice spare tire, but a decent amount of muscle thrown in. Here are some tips that have helped me some this past month:
1. Try and do some low impact cardio work on your off-days. I prefer interval training over steady state.
2. Make sure to get a meal in a couple of hours before class. I used to be worried about my stomach, but about a minute into my warm ups any stomach problems I may be having go away. When I first started I would just have a protein shake before class, but I find that I gas less when I have actually had a full meal.
3. This may be a no brainer, but I was smoking, but only a couple of cigs a day. Even cutting that small amount out made a huge difference.
4. I used to really gas when mounted trying to use my strength to escape. Sometimes it worked, sometimes it didn't. Didn't matter because I was too tired to do anything after that point. Focusing on technique allows me to last longer when rolling. Before I would have a lot of trouble lasting 2 consecutive 5 minute rounds, now I have trouble going 4 consecutive (hey... it's a start).
5. Remember to breath!
And dammit, my toes hurt like hell! I think I have minor turf toe on my left foot. :icon_evil