Thanks rmur. So true that the difference between .75 and .85 IF is significant, given how you arrive at that IF. For example when I do 2x20 I have to ride 9 miles o/b to my favorite climb (ravaged by the Tea Fire btw ), and by the time I build in the time it takes me to descend after the first 20 my IF is in the .7x range, not the .8x-.9x range unless I drill it out and back, unlikely because the road is v twisty.rmur17 said:good post. Personally I've found a large difference in sustainable load (CTL) at an avg. weekly IF of 0.75 vs. 0.85- even though that doesn't sound like a large change on the face of it. But ex. phys tells us the response isn't at all linear.
At 0.75, I could handle around 140 CTL, at 0.85 it seems 110 is much closer to my limit. If I were riding a lot of L2 down around 0.65 and had the time, I suspect I could get into the 170s or higher. Just idlely working that out, at an avg. IF of 0.65 that would take around 4hrs/d on average or 28hrs/wk. Not impossible if one was doing nothing else but probably a colossal waste of time for an amateur/master.
In the end I do get 40' of L3/4, but I wrap some L1/2 around that lowering the IF dramatically. I do 2x20 or 1x40 3xs per week, but I do them w L2-7 wrapped around them, w my roll out/back as stated above, or before/after a group ride.
Right now I can get away with that in that at this stage of my life I have more time on my hands and flexibility in my schedule. If I were in the OPs shoes I'd be doing the HIT thing, namely 5' warmup, 2 x 20' w 5 rbi, and a 5' wd. In fact I wish I had a PM when I was younger and time-constrained as I would have a far more efficiently and better trained athlete following a HIT approach.