I used to swim and it was awesome! I had the highest PFTs of my life (130s). I wish I could still do it, but I have transportation and scheduling issues because of working and being a mom. Right now, I do the stairs at my apt. as well as jumping jacks (someone on here recommended them, thanks), push ups, crunches...I've found, for me, that anything using my arms is better than not. It gets me breathing harder because the muscles used for breathing are the same ones you use with your arms, so it stresses your breathing more than say, cycling. But, I do love a bike-ride, taking a walk...I'm not much of a runner, I wear out pretty fast - always have. OH! My daughter and I have a game that's good exercise. We stand at the edge of the driveway (at the street) and kick a ball as far as we can up the driveway to the yard. Then we run as fast as we can to get it and bring it back to the starting point. Then we do it again. Kind of like modified eraser drills. It's fun and she helps keep me going long after I'd lose interst.