Originally Posted by
Mr. Underbridge
Basically, the typical MTB just doesn't seem like the best tool for the job if all your miles are ridden on roads. But by all means, do it if you like it - you'll certainly get a good workout!
I'm not sure this last sentence is correct. The typical gearing on a road bike should give you a better workout than you'll get on a MTB ridden on the road. If you're using the taller road gears for more speed, that is. (IOW, If you're using the "tool" properly.) I often max out the gears on my MTB, not very often on a road bike.