Originally Posted by
Saving Hawaii
But this has nothing to do with exertion. If I go over to the local MUP and do sprints all day on my road bike and my mountain bike, I'll have much better times on the road bike but I'll have tuckered myself out pretty evenly on both. The road bike goes faster but the resistance that your legs are working to overcome is essentially the same. You just end up traveling a few extra miles in the same amount of time. And frighten more pedestrians.
The highlighted statements above are scientifically impossible...
There's a huge difference between walking up a hill without a bucket of water and walking uphill with a full 20 pound bucket of water. The latter requires more energy. Mustering more energy is called, "physical exertion". Cycling is all about fun, excitement, and physical exertion. Heavier cyclists, carrying heavier loads, exert more energy by necessity. This is particularly true whenever going uphill and during acceleration. It's also true whenever you traverse rough terrain. That's only because on uneven surfaces, you have to constantly overcome the higher portions of the road. Sort of like constantly climbing little microscopic hills. This requires the cyclists to overcome resistance almost continually. The heavier the load, the more resistance the cyclist has to overcome. Road bikes generally weigh less than mtbikes. Therefore, they quite naturally require less energy to cycle.