If you want to compete seriously these days(BJJ or MMA) you need that strength and conditioning element in your game. I compete for fun and knowledge, and I don't think I would learn BJJ faster if I was fit and strong. I would just win more, not learn more. I am in great shape for an old 150 lb skinny white boy that has never strength trained a day in his life. I can roll non stop for an hour with people much bigger and stronger than me. If I get tired and stop rolling then I ain't learning. So just rollin' lots keeps me in good enough condition for my current goals. Getting big strong guys to stop using muscle when rolling so they can learn is always a challenge for me vs skinny weak guys that have no choice but to work the technique. This might be a small advantage to training gi. (please don't start gi/no-gi debate) A larger guy can't just bench press me off side control with a gi since I have "handles". Since he can't just muscle out, he is forced to use proper side control escapes to gain position. BUT, a strong fit guy that has learned and uses proper techniques is a very scary individual!!! I have teamates that say they are not using strength against me, and they are not, until I am just about to seal the deal, then I feel the body tense up and just explode with every bit of muscle they can muster, just so they don't have to tap. This is before they even attempt the proper technique that I know they know. I often pause and give them the chance for proper escape, that they don't even attempt before going berserk. They are helping me with my street fight ability, because big strong people in a street fight will use it, so I get better at clinch control, thanks. But they are not getting better at BJJ by going berserk. I always type so dam much, sorry, I stayed at a Holiday Inn EXPRESS last night!!!!