my base building rides are a bit harder than they should be. I'm usually aiming at a certain KJ goal (if you care why, i'll expound) which is typically 3000-3300 right now. So, time often becomes the next factor.

If I only have 3 hours, after a 10' warm up, I usually aim @ around 85%, knowing that on decent legs, I can hit my KJ goal in that time frame.

On the weekends, I have more time, so I'll typically take the intensity down a bit and ride closer to 4 hours, but still aiming for similar KJ goals. These rides, albeit longer in durration, are typically lower in TSS, and are easier on my body/brain.

So I prefer 1 of each per week. that's 7 hours and 6000-6500 kjs and about 380 TSS points in 2 rides. After this, I just fill in when I can with either 2 more solid training days of tempo/SST OR 1 good day and 2 days of either less time or intensity. Either way I'm looking at 10,000-11,000 kj weeks right now.

As fitness imporves, the duration or the rides wont change much, but the TSS should come up steadily as I begin to increase intensity gently over the coming months.