I'm one of the few people who isn't working on losing weight. Not that I don't have some spare pounds to shed, mind you... I just don't mind.
5 years ago I was lifting weights but doing nothing for cardio. 3 years ago I started riding seriously again and 20 miles was a long day on the bike. Last year I did my first double century in over 15 years, and this year I've already done 7 century rides or longer.

I'm 250 pounds and I've been down to 235 in the past year. My distance riding suffered immensely when I put forth the effort to lose weight. I was tired all the time, I had a tough time riding more than 200k at a time, I was constantly hungry. At 250 pounds I have no problem sustaining 17 hours in the saddle, and the important numbers (BP, RHR, cholesterol, etc) are no worse off than when I was 15 pounds lighter.