What are your opinions for a beginner on BJJ and weight lifting? I've been doing BJJ for a few months and love it. My conditioning's gotten better, so that if I'm rolling with someone at the same skill level/weight, it can be a standstill for 5-10minutes with neither gassing out. We can both focus on technique -attacking and defending. Same for heavier guys who's at the same or worse skill level, but i'm not strong enough to keep them in position or finishing a sub without them powering out of it. I can get the better of guys my weight with positioning/subs, but not guys 30-50pounds heavier. For these heavier guys, is it because a lack in technique, strength, alittle of both? Will weight lifting weaken my conditioning by building more muscles and burning more oxygen? I'm more concerned about being able to keep them in position then submissions, such as side control/mount, without them easily flipping me off or power out. Thanks!