Originally Posted by
Carbonfiberboy
Well, it's because endurance doesn't kick in until you start to endure. It's kind of a definition thing. You can't expand your limits without pushing your limits. OTOH, you don't really need to ride long except once a week. So focus on that weekend ride. For that ride, if you're alone, ride out until you are quite tired, then ride back. Push your limits. Randoing is the Dark Side of cycling. Embrace your dark side. Suffer.
Then your weekday 1 hr. Z2 rides will be just fine. You'll need them to recover and just get in the weekly miles. I like to see around 150 miles/week for randoing on non-brevet weeks.
I'm not sure what would be accomplished by adding 1 hr. Z2 rides in the schedule. They are too short to build endurance, too slow to build power, and simultaneously too short and too slow to burn fat. If I had time to ride for 1 hour/day on weekdays, I'd do either intervals or Z3/Z4 3 days per week and sit on the couch recovering the remaining 2. (Adjust intervals to couch ratio as needed, based on observed fatigue and performance.)
P.S. Just so we're all on the same page here, are we talking about Z2 meaning 80% to 90% of heart rate at lactate threshold, e.g., if my LTHR is 160, then Z2 is 128 to 144? There are multiple competing definitions. According to this one, I have be super tired and/or consciously restrain myself on every small hill to keep from getting out of Z2 and into Z3/Z4.