Here's a great video on the subject.

I'm 77M with a 4.6 cm ascending. I go to the gym for resistance training and cardio. But, I do more reps with lighter weight, and never push the last rep or two. In other words, don't strain. Never hold your breath while straining. That was my natural inclination earlier in my life. That creates tremendous pressure on the aortic wall...very dangerous if you have an aneurysm. I don't think pushups are recommended from what I've read...

For cardio, I do a 45 min. low intensity stationary bike, 3 to 4 times a week. You don't really need to push it. You should be able to carry on a conversation.

If you haven't already discovered Perplexity, it's a great source for researching anything. It's a search engine that gives you answers, but footnotes the source material, so you can read the research yourself. It's amazing!

Sounds like you're doing great!