no. it's a genuine question, i definitely noticed it recently.
Me too, starting to think MTBing might be a "fat person sport". Like darts or, as some other people have said, walking.
Because most mountain bikers are only mountain bikers for three of four hours on a sunday and do **** all exercise the rest of the week. That's not a good way to keep the pounds off.
Or often, even less then once a week. And then they are surprised/come up with a load of excuses why they can't keep up.
OK riding up hills is more intense than hiking up them, but overall it's much less effort than fell-running, aerobics, boxing etc.
Dunno, I've got my heart rate up to 211bpm on the bike. Don't think I've ever got it that high in boxing (not that I measure it). I think the problem is a lot of people see a hill as hard work that just leads to the next descent. Rubbish. Climbing is fun. People who flee to the comforts of their granny ring at the slightest hint of an upward incline are kinda annoying, they just hold up everyone else because they don't want to try?