Unfortunately this particular intervention wasn't successful (not much difference between treatment and control groups). But conceivably, afib triggers is something that varies from person to person and perhaps a future design would tease this out.
Biggest triggers are caffeine, alcohol, and sleep deprivation (correlated with my sleep apnea events) for me. I see exercise is only reported as being slightly higher than caffeine here, but exercise (stationary bike, strength training) usually causes my episodes to self-correct; I usually attribute this to the more controlled breathing during exercise, but I have no proof. I also seem to have a much larger threshold of triggering AFIB with alcohol than I do coffee. I have to reach the moderately drunk stage to induce a flare with alcohol. If I keep things near a light-buzz, I can typically get away with no issues.
At that time, I was on an opioid pain killer for an abscess. The next time I was on an opioid pain killer, years later, I also had an afib episode. So I wonder if maybe I have some sensitivity to opioids.