Broken ribs suck big time. I got taken out by a car last year and broke 2 ribs. I kept going on the trainer only in zone 2 for about a month before being able to take a deep breath. Lots of walking as well, about 5 miles a day. I lost loads of power for sure. My FTP must have dropped 50W. i got it back a few months later, but the whole episode ruined a complete summer. I couldn’t swim or run for 10 weeks.