I'm sure I don't do it, Ray, because I had to Google it:)

not a crossfit person but I have had the total gym for ten years (you know, the machine that Chuck Norris and Chrisy Brinkley promote).
diagnosed with Afib two years ago and have not altered my physical activity. I play tennis in the Florida heat, work out everyday, swim and do some yoga stretches.
in my case, Afib does not inhibit my activity and exercise is not a trigger. I do nap a lot more but that could be the meds or the Afib condition. everyone is different; make changes in moderation and build on what works and always tell the docs what you are doing. hope that helps, be well, Rich

I have not done Crossfit or P90X. My belief is that the intensity should be proportionate to your age, overall health, the fact that you have AFIB, your Doctor's opinion, and how you feel. I like the idea of muscle confusion. I was telling my wife about it and she said, "Do some work around the house, that should confuse your muscles!". :-)
Anyway, my brain tells me that moderation is the key, but from what I have seen, it would be like telling someone to do excess in moderation. With that said, I read on a medical website that strength training is good for otherwise healthy people with AFIB.

Hi Ray,
I don't do crossfit, but do exercise regularly (5 days/wk). My doctor has always encouraged me to contiue exercising with no restrictions. I would ask your doctor and see what she/he says. AFib does not restrict my exercise. Nate