The main issue with exercise is avoiding any exercise that leads you to hold your breath and/or grunt, that is common when trying to maintain back stability, sometimes while doing planks, crunches or lifting heavy weights. It is known that during those moments your BP rises significantly and high BP is the worst enemy of an aneurysm. That is why cardiologists normally tell patients to limit weight lifting to 30lbs. I have posted videos in this forum about exercising and aneurysms, look through my posts and you will find them. One of them is from a cardiologist who does research in the subject the other is by Dr Andy Galpin with Dr Huberman, it is not about aneurysms but how and why straining makes BP increase and by how much

On the other hand keeping your body healthy it’s paramount in case you ever need surgery to repair your aneurysm. I had mine repaired in 2020, I was 54 and my aneurysm was 5.2 cm. I was in very good physical shape and my surgeon gave me >99% of having no complications. I was out of the hospital in 5 days back to work in 3 weeks