I had a strange thought today...

I am 40 and have always been somewhat heavy, and I am currently very overweight. At various points in my life I have applied myself and found that I have a metabolism that supports strong, extended cardio exercise, which seems unusual for someone of my BMI.

On Sunday I completed a 42 mile ride averaging 14mph and on Monday did an aggresive spin class. My legs were a bit stiff, but never sore. Earlier in my life I did cycling, sprint triathlon, and crew, all carrying a little to a lot of extra weight.

I have also noticed that a significant percentage of moderate to fast paced group riders in this area are middle aged and somewhat overweight.

Is it possible that generally (not morbidly) overweight people have a bias towards cardiovascular capacity or endurance?