I'm excited. I started biking a month ago, just going to the gym instead of walking or driving. I had fell into a slump with my weight loss. I started out at 430lbs and got down to 320. I was back up to 350 and now am back down to 330. The gym is only 2 miles away and it killed me at the beginning. Today I went a full 8.5 miles without having to stop. I tried it Thursday but I could not do it, I had to walk a bit. I am happy I have logged 52 miles since Wednesday!!! Also since Wednesday I am down another 8 lbs.
Keep it up!! I remember when 5 miles was all I could ride. That was a little over one year ago. Today I went 62 miles with 1600ft of climbing. Keep riding every day and you will notice a steady increase in performance.
Good job! I think you'll find biking an excellent (and fun!) addition to the gym workouts.