Originally Posted by
grantelmwood
An 8 mile ride with 15% hills is harder than a 100 mile ride on a cute little bike path for kids and grannies
You sure about that? For a fit athlete with an appropriately geared bicycle, hills shouldn't be too inherently difficult. Unless you are under-geared, one's effort is independent of the terrain in which they ride.
Granted, my perspective is from a modern, competitive cyclist of 15+ years using modern technology (power meters, electronic shifting etc).