Originally Posted by
Alias530
You can't say a road bike is better exercise.
You could say something like... for constant exertion without interruption, road bikes are easier to put constant strain on your body, because when mountain biking on trails you can't always be pedaling.
But if you're pedaling the same pavement, at the same power, you will burn the same calories. If it's easier to go harder on your road bike it's either a mental thing or your road bike fits you better.
No, it's better exercise. I put out the same mental effort and both and the road bike kicks my ass and is funner. That is the bottom line. It's not close.