I have been a part of the ATA and yes it is very good. Also I have been part of USTA united states Taekwondo Assoc and they focus more on the sport and not the endurance. Both are great and you will lose weight. I was at my best shape when I was involved with them. USTA is more for the person wanting to learn how to break bones, at least that was my experience. I personally like the USTA more.
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