Our bodies react at least a little to any discernible and undetected stressors. This could be indigestion, over-eating and having a distended stomach, swallowing air while you sleep, constipation and/or slow motility and infrequent BMs, caffeine, histamines, nicotine, illegal drugs,over-the-counter cold medications with ephedrine and other stimulants, anxiety, ruminating (thinking over and over the same thoughts or worries), insomnia, vitamin and/or mineral deficiencies or imbalance (electrolytes, for example)....I could fill a page easily. Oh, even comorbidities that flare up can set one's heart off.
However, it is incumbent upon each of us to attempt to learn what makes our hearts react with palpitations and outright arrhythmias. (Note that a palpitation is a sensation, maybe even followed by alarm or dread, that the heart is not beating properly. It is NOT necessarily an arrhythmia.) Trial and error are the best way to figure it out. Keep comprehensive and reliable records and notes that you can use to guide further experimentation.
If it helps, I was active all my adult life. I was in the combat arms in the Canadian Armed Forces, but also a competitive runner. Latterly, I took up paddle-boarding, cycling, and snow-shoeing. I didn't do any of it lightly. My cardiologist simply opined that I have an 'irritable' heart. It got tired. And cranky.
AF is a progressive disorder. For everyone who has it. The sooner you deal with it positively and constructively, the better the outcomes over time. For example, you describe your AF in terms that would have us and cardiologists label it as 'paroxysmal'. It comes and then you revert yourself to sinus rhythm. For many of us, we can keep that up for years. Eventually, though, things will slip just like tectonic plates do, and the your living experience is likely to change suddenly for the worse. People such as yourself with paroxysmal AF have a much better result with rate control at first, and then by getting an ablation to isolate the pulmonary vein ostia, where the veins return oxygenated blood from the lungs and empty into the rear wall of the left atrium. Atrial muscle tissue migrates into the ostia in many cases and becomes responsive to the electrical signals that come from that location. The result is extra contractions, unwanted ones. The ablation will scarify the tissue around that area using radio frequency or other methods. The 'stockade' of burn marks, lesions, will not permit the spurious signals to get past them, so the atrium continue only to beat with the correct signal that is left to it.
Others will chip in with their comments. You'll get a lot of help and some hand-holding. It's a sobering thing to learn that your body is time-limited in one way or another. This is just one of the ways.