Posting here for traffic. I had covid in October and had awful breathing problems and couldn't work for three months. I'm fine now except that I'm so unfit, and randomly have periods/days of breathlessness. Absolutely no obvious cause behind when i have these periods (all this weekend for example). I might have a week of being completely fine next. On the plus side, I've got a good treadmill, and a rowing machine. On the minus side, healthcare here is such that I wouldn't know how to ask for advice about building myself up and I can't afford a gym or trainer. Caveat - please don't worry about me blindly following advice from here and hurting myself. I've got enough sense to self manage, but some tips from someone who's been here before me would be very welcomed. :)