Hi Nadanoel,
My background is similar. Almost 82yo.
Diagnosed with AF/tackycardia at 71yo.
Ablation at 79 yo... it failed.
Now on Metoprolol.
Exercise is so important for us "'ol Foggies". I reluctantly gave up jogging at 72. I now do Tai Chi ("the moving meditation") and walk almost daily. HIIT is better for us than steady running/jugging. Because I live in a neighborhood with steep hills, Prescott, AZ, it's perfect for getting my HIIT in ... I just push to go quickly up one hill, then "coast" as I progress down the other side. Keep movin'.