Do what you like to do and do as much of that as you can without getting overtrained. If you're having fun, you're more likely to get the volume up. I mostly do the boring Z2 stuff on my rollers, weekdays. Weekends are for fun and the real training. Did my 2nd Sunday ride of the year yesterday, hilly ride, almost no Z1 or Z2, lots of Z3 and almost as much Z4. I'm way out of shape but I'm on my way back!.
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Results matter