Would be interesting to learn whether some of these people tend to revert to sinus rhythm during exercise "warmup" and whether their performance is impaired or not as to competitive level My impression is that when and if atrial fibrillation has become persistent into exercise then the level of performance drops very severely. (As to the oxygen intake or "mets" that can be sustained during running or even whether anything more than a feeble slow jog at a high perceived effort level can be attained.
Thats my experience, I only get afib during or after a race or after high intensity training. Never in daily life, and I guess Im lucky cuz some people have it all the time.
What if you could survey a group of very high level (or former very high level) athletes such as restricted to people who have won major running events,100 mile footraces,"Ironmans" , Medalists in Olympic endurance sporting events,world class soccer players etc. --for A fib Controversy that some of these people have enlarged heart not because of activity but rather had constitutional large hearts that empowered them to dominate the events such as they did (with appropriate training of course) ??
