Naw, that would be my ticket. Heavy smoker for thirty years, A PFO discovered after the stroke in 2008. Run away tachycardia in 2013, the cardiologist in the followup saying the only thing that saved me was a strong heart (must have been what cardio exercise I did have in life). I have been in constant afib for four years. Cardizem and huge dose of metoprolol to control rate which keeps me from doing a lot of exertion (heart not getting to an aerobic speed).
So yeah, I have a hard time after a three minute round but I was out shoveling snow earlier this week.
It can be easy to judge someone on appearance and it is true that many with a lot of muscle mass can develop problems in life. My back went first, doing silly human trick stuff.
Cheers
GC