Its a long story and more a topic for the health problems thread but the short answer is cardiac rehab after a heart attack.
I do 30min daily cardio with specific heart rate goals/limit 7 days a week plus 1 hour 3 days a week (mwf) of monitored cardio (at the hospital while hooked up to an ekg)
I also do 1 hour of yoga 5 days a week(m-f). This one is voluntary rather than doctor ordered and yoga is more a mix of cardio and calisthenics but leans more cardio to me. I could quit the yoga but it's the only one of the 3 activities I actually enjoy doing.
So I end up doing 2.5 hours of cardio mon, wed, fri, 1.5 on tue/thur and 30min a day on sat/sun.
I dont know if that's a lot or not cus I've never been big on doing gym cardio so it seems like a lot to me. Until recently I've always relied on my physically demanding job plus activities to cover my cardio needs but for the last 2 years I been working a sedentary office job so gotta do it.
I'm starting to add wt training with a little home gym I got setup