Makes no sense. My 2 cents: From what I see on Strava my 1 1/2 hour rides are burning 100-200 calories if thats correct it barely burns off half of breakfast. and 2: runners they say run because theyre skinny, they're not skinny because they run. Their bodies are built for it, they excel at it and thus they are motivated to do it more. A lot of overweight people ride or run with some hopes of being like those runners but were never built like a gazelle. This does not mean they get no benefit from exercise though. Biking esp mtn biking is about manuevering your weight and hauling it on the bike. People are concerned about 2 lbs on a frame but are carrying 35 extra lbs in their gut. Its like having a 2nd bike on your back, again still doesn't mean excercise provides no benefit.