I am trying to get 4 hours of cardio per day following a modified version of Lyle McDonald's rapid fat loss. The first hour I do incline treadmill at 15% grade at 3.0 mph. This is about 9.65 METs. Is it difficult to reach 9.65 METs using a bicycle or elliptical?
10 mets on a bicycle is the equivalent of ~ 14 mph. This is a fairly easy pace and should be easy to sustain for a while, unless you have never really ridden a bike much other than a beach cruiser around the block.
Here is a link for a met exercise equivalency chart, there are dozens of them scattered around the web that show MET's for various exercises.