I’m starting to love these, this was yesterday. Working my way up making the sets longer up to 3x25 over this block after my initial stab at it I found I could progress length of the sets longer much quicker than anticipated;
Further to @kurt.braeckel point, given we are still in base phase for me this is meant to be a high-end SST workout not threshold or above. So if NP for each set is still 94% of FTP the way it’s configured with 2min under 30s over.
Some interesting reading here regarding O/U work as it pertains to some legendary runners. Hard for me to equate their pace to % of FTP, but it sounds like the under doesn’t need to be too hard, maybe even better to go on the low end of SS or high end of tempo. At any rate, these are amazing workouts that I benefit from and I love doing them for a good block.
Magic in the float
The new science by Brooks, Thompson, and others has produced a theory for why it works, and with it, insight into how to fine-tune Prefontaine and De Castella’s decades-old methods. Brooks’ studies suggest that the ‘magic’ in this type of training comes from the float, not from the higher-intensity work that preceded it. The primary function of the fast parts of the workout, it turns out, is simply to work you hard enough to cause your blood lactate to rise.
Once that has happened, you transition to the float. This trains your body to clear lactate efficiently, while still running at a brisk speed – though not so brisk that you are still accumulating lactate. In other words, what you are training is the lactate shuttle.
There is no single best way to do this. Rather, it varies with your goals, personality, and, ultimately, inventiveness. Prefontaine did it by running really fast 200s—fast enough to quickly build up a surplus of lactate then following them with recoveries that were a full 33% slower.
The second part of this is what’s interesting, the intensity of the float or under.
Now should I re-name this thread to “O/U progression” ? 
That’s essentially it. I like to try to build the ability to work hard after a hard effort, thus for me I found good workouts at doing 30s/2:00 or :45/3:00 and focusing on a somewhat harder Under rather than raising the “over” power.
At the start, a :30@110% over might not burn, but after 30 minutes of this work, it definitely does. Now, I think you could potentially scale it in the same way that coaches like KM apparently prescribe VO2max work in that you scale it back later in the workout, just going by “feel” the entire time, but with longer sustained intervals, it’s going to be a lot harder if you burn up matches at the start trying to get a certain burn, rather than just letting it build as fatigue builds throughout the duration of the workout.
So, in base, I’m looking to shuttle lactate and increase the power I can operate at while doing so (the Under) far more than I’m worried about hitting a higher power target during the over. And then I want to train how many overs/unders I can do, and then I want to spend more time over.
The issue I’ve had with TR’s O/U structure is that I think theirs spend way too much time “Over”, personally. A lot of their O/U workouts are great, but some of the later ones they prescribe just spend too much time above threshold (and usually at 105%) for what I think they’re trying to accomplish.
Kind of what I settled on last block of these was 92% - 110-113% with a 4:1 ratio of under to over time. Then adding more total TiZ. I started with a 2x20 with 2:00/:30 at 92%-110% and progressed to a 3x18 on 3:00/:45 92%-113%. These were achievable without crushing me. If I’d kept going, I would’ve gone to 3x20 and bumped the under to 94%.
If I was doing a race simulation workout, I would probably do a higher over (120-140%) and then float at a lower power like 85-88%. I do really like the “over unders” Chad calls billats in short power build, but I wouldn’t do those in Base because they’re friggin’ hard.
All MO, I’m not coaching anyone, so do what you think is best or what works for you.
KM normally gives a number for the overs. I think it is generally pretty close to 5 min power.
I know a top coach in the UK prescribes sweetspot rides with bursts. I believe they’re 15s sprints then straight back to SS.
Thanks! For me 5 min power correlates to 118%, so there you go. Everyone just go with Hunter Allen’s recommendation and ignore me. 
The point you raise about using PDC and a power number rather than a % of FTP is a good one. I was targeting 310W from an FTP of 275W. 5 min power was 330W.
Add: I just went back to my notes, and one of KM’s podcasts mentioned an over-under starting point of :30/2:00 with overs at 5-8min power, unders at SST.
For those that are wondering about the progression of these blocks; Super happy with results of this intensive aerobic block. Progressions at threshold are coming along really well and I can really feel the difference in ability to hold power for time, something that I was NOT good at being more fast twitch and anaerobic reliant.
Two weeks in already able to hold 3x20 when I was only scheduled to do 2x20 today.
Great work. If others don’t mind, I would be interested in reading your progress (and others who are doing an intensive block).
Do you mean 2min under at SST and 30s over at 5-8min power on PDC?
Yes. I started my over/unders at 2:00 92%/30s @8min power for 2x20.
Progressed to 3x18 of 3:00 @92%/45s @ a little more than 8min power.
After this discussion and notes review, I will play with overs at 5 min power next time, but want to have the unders be at 92-94% still.
So are you sprinkling in over/unders during your SST progression block? Or is this considered a new block and you are reducing the length of intervals to account for the increased intensity? If so, by how much?
See above for my over under progression. I did FTP intervals in my block as well, progressed from 2x20/5 up to 3x16/4 over 3 workouts.
My intensive block didn’t go great as my CPAP failed so my sleep was 
for two months and my club lost a club mate so I was struggling with motivation.
I hope to get FTP intervals out to at least TTE (a bit over an hour) next try (April).
I’ve done 4 weeks so far with an additional easy week in the middle. Usually something like this:
Tues - O/U progressing over duration, lately 2@105%/2@95%
Wed - Z2
Thu - 97% to TTE (e.g. 3×20/2×30)
Fri - Z2
Sat - 97% to TTE or over
Sun - Z2
I increased my FTP by 5w at the start of the block and have pushed out to TTE+20 mins so far. Making the easy days easy has been essential for me in this block, and I’m still riding close to the edge.
Thanks. Easy days easy is spot on. I would/will keep well away from the top of z2 on these rides.
I haven’t drawn up my next block yet, but it will be mostly focused on pushing out TTE with long sweet spot and tempo work. Just wrapped up my VO2max work, so planning to step back intensity a bit as I don’t have races coming up.
I will add the over/unders alongside FTP intervals (97-100%) during the next block.
Question for the crowd that’s done the VO2max blocks:
Background: I’m 43. Long running and triathlon training background and last three years only cycling consistently, putting in ~500TSS per week in 8-10 hrs on average this season.
I did 8 VO2max workouts in 18 days, rest zone 2, over the past 3 weeks. Entering recovery. Obviously pretty cooked.
I’ve blocked out this week for recovery with the exception of my group ride on Saturday which won’t be a big deal. Next week I’m tentatively planning kind of HVLI with some residual testing (two sub-1:00 tests) and then FTP/TTE 45 min power test next Friday.
About how long has it taken you all to recover from this block before you felt good for training? I usually bounce back in a week or less from my blocks, but never done the specific VO2max block before.
TIA!
I popped real hard my last VO2 block. Knocked me out for about 2 weeks. Other times it’s been a week and I could do real work again.
For me after vo2 block ( (2 weeks, 3x vo2 per week block) it is usually 1-1,5h week. After that I am able to do proper block.
It was 2 weeks for me as well. Did 2 weeks of 3 x VO2 then totally trashed for a week. Did an FTP test 6 days later (just the ramp) which went well and was able to do a short sweet spot ride right after but it cost me. Second week saw a few failed workouts and generally being lethargic. Third week I was back at it no problem.
I’ve got a question for the group too…
I just finished the SS progression over two 4 week blocks. Managed to extend out to 90 mins at 90%, which is astonishing to me, I’m really happy that I could. Before this phase, I ran through the full SS LV 12 week plan.
So, does it make sense to do a VO2 block next and then come back to a threshold block afterwards? Or should I stick to the threshold then VO2 pathway? I’ve got space for two more blocks before I shift to a specific plan for my a-race (middle distance triathlon) in June.
Looking at my WKO5 historical data, my mFTP as % of VO2 is about has high as it has been historical. I think that was in a recent WKO webinar as a good marker for a change in stimulus(?). Figure it makes sense to raise the ceiling before pushing the FTP power one last time.
