Originally Posted by WhyFi

Again, I think that you're missing the forest for the trees - by all means, get better rest, but I don't think that this is a problem that you need to actively fix otherwise. You're going to have days where you feel off and days where you feel like a world-beater - that's natural. You may be better at one time of the day than at others - not necessarily a big deal, being off by 10w morning vs evening wouldn't be a blip on my radar.

Further, you don't really want to go out there and ride at the same output/pace all of the time, anyway, whether that's full gas or café pace. You really want to switch it up. Hell, at this point, making a point of having easy rides would probably benefit you more than just trying to hammer all the time.