I was 54 when i had my surgery 4 years ago, I was in very good shape and exercised frequently (not as extreme as you), never smoked, they actually found my 5.2 Ascending AA after I broke my leg after falling from my MTB. Based on my body size (aneurysm was considred too large) and physical shape (minimum risk duing surgey) my surgeon encouraged me to have it fixed as soon as possible, had to wait unil my leg healed from surgery a bit since they want you walking right after. I actually wanted it done immediately, couldn't handle the stress of knowing I had a ticking bomb. The main thing you have to watch is your BP, they never said anything to me about Heart Rate, and they limited my weight lifting mainly because when you push we tend to hold our breath and during heavy exertion while holding your breath BP spikes puntually to very high levels (I shared a video in this forum, different discussion, of an expert explaining the reason and how high your BP can get to at that moment). of course I was also limited on my exercise due to my broken leg. The surgeon gave me >99% probability of no complications, I was out of the hospital in about 5 days, back to work in 3 weeks. I am back at exercising everyday with annual check ups (I have a bicuspid valve which contributed to the AAA) to check on my valve.

Hope everything goes well for you