Is the health benefit/caloric burn determined by mileage or by time spent cycling/effort exerted?
When I was swimming for weight loss I read somewhere that it didn't matter how far you swam, just how long you swam (as long as you were really swimming). That a poor swimmer burned as many or more calories as an efficient one.
Does having a heavier bike that is more work to ride a better workout than a bike that rides smooth as silk?

