I am border line stage 3 and was diagnosed 3 years ago. I don't require oxygen at this time. Exercise is extremely important and you have to see what works for you. I walk 3 miles three days a week,I get up early and walk at 7am. I bought a regular push mower and I mow the yard once a week. At first it took me 2 days to complete but now I can mow in about a hour and a half, taking water breaks as I go. Weight is an issue because the more you weigh the harder it is to breath. I eat a lot of protein and with the excerise I manage to maintain a healthy weight. Take a lot of breaks if necessary because as you go you will see you will need fewer breaks and you will take pride in you success.