My awesome wife just bought me a trek 2.1 for my birthday. This is my first real road bike. My whole life i've been on MTB regardless of trails or on the road. I noticed it is much quicker and so much better of a bike, but why do i feel like all the riding i did this summer meant nothing once i got on the road bike. I was coughing up flem again, and had tired legs at only half of my normal route. Is there such a difference between Road/MTB that it affects totally different parts of my body?