wait "A test uphill will always give a higher power output than the flat and power to weight ratios will make the test less accurate."
why is this? if u are able to do lets say 300 watts for 1 hour going up hill why is that less accurate than being able to do 300 watts for 1 hour on a flat? (if i'm reading into it correctly?)
I think their reasoning is that on a flat you do have small downhills which can lead to lower power as a result of lower resistance. Whereas when going uphill you will likely be constantly riding against gravity and have resistance.
Ideally speaking, you should not let downhills lead to lower power, but it is a difficult thing to perfect and most people are unable to maintain steady power going from uphill/flat to a slightly downhill. So "technically" most people will have lower power as a result of riding flats, but I would not use the word "always".