BJJ

No, jiu jitsu alone does not build muscle in the sense that pure weight lifting does.

On average the basic bjj class burned 575 calories and an advanced bjj class (more sparring*) burned 750 calories for a 190 lb male.

Brazilian jiu jitsu originated when Japanese jiujitsu and Judo was brought to Brazil by Mitsuyo Maeda in the early 1900s where it was taught to Luiz França, Jacintho Ferro and Carlos Gracie who are credited as the founders of Brazilian jiu jitsu.

Wrestling teaches a faster pace and stronger emphasis on takedowns and pinning techniques in its athletes while Brazilian jiu jitsu puts more emphasis on leverage, control, and submissions with less emphasis on takedowns.

The best way to learn from jiu jitsu instructionals is by splitting them up into small digestible chunks, watching and understanding the material, drilling the techniques, and then using them effectively in live training.

There are six basic bjj positions which are full guard, half guard, side control, mount, rear mount, and turtle.

For how to find a good jiu jitsu gym you should ask yourself:

is it competition focused?

amount of members

is it gi or nogi focused or both?

how many high level practitioners train there?

is the lineage of the head instructor legitimate

are they only jiu jitsu focus or do they offer other classes

travel distance from your home to the gym

cost of membership

are certain jiu jitsu belts only allowed to roll with others of the same belt

does the class schedule work with your own personal schedule

what is the gym culture like

In a survey performed at my gym, the best bjj submissions for beginners are rear naked choke, triangle, kimura, arm bar, guillotine, and arm triangle choke which all can be effectively learned as part of jiu jitsu basics.

For the question, how dangerous is a purple belt in brazilian jiu jitsu vs untrained individual, they should be able to defend, control, and submit nearly any untrained opponent. They should have technically efficient movements and vast experience of performing jiu jitsu techniques in live sparring situations.

To answer the question, how long does it take to learn jiu jitsu, it takes ~6 months to 1 year to learn jiu jitsu. This includes learning all of the basic goals, positions, and submissions.