When is the best phase to use these type of intervals (30/15, 40/20 etc)?
is it during base phase?
I find this one of the best written perspectives on when to use polarized:
That is the opinion of one coach. Here is another with a similar opinion with respect to road racers:
Very true… here’s a fun fact to go with it. The human mind processes narrative information at up to 10x the rate of normal spoken delivery. It’s a major reason why we sometimes struggle to pay attention to each other - the mind tries to fill the spaces while awaiting more info from the speaker.
Eh… isn’t that what they do in prison?
True. Even more so when you are phased out because of the VO2Max work. My first attempt (in my life) at the short intervals with turnarounds - or better on intervals.icu wasn’t that bad. But next attempt was on a longer hill just going straight.
Depends. I am fairly light and can climb in my Z2 with reasonable cadence up to around 10%.
Can’t say for sure. Like the anaerobic zone, I try to stay out of it as much as possible. 
Cool, you can see the down and up little bumps all the way up the hill! Only myself (as the one and only admin) and people who follow you (on Intervals.icu) will be able to see that ride. You should post a screenshot here.
I don’t think I will manage that on the hills near my house. Traffic to deal with unless I go really early in the am. And I am not that good at downhills or cornering!
Thats amazing unless you have really easy gearing! 
Damn you 
Fantastic breakdown and read, Brendan! I really appreciate your contributions!
Thanks for linking these. Paraphrasing Friel:
“Intermediate and the less experienced of the advanced athletes may make great gains by training with the THR group’s method—lots of time at about AnT. This way is somewhat similar to what Coggan proposes with his “sweetspot” training methodology with 2 x 20-minute intervals at 88-93% of FTP with 5-minute recoveries. I’ve seen a lot of athletes improve by training that way.”
The above covers MOST of us. There are many ways to skin the cat. No one way of training applies to everyone. It’s f-ing useless and tiring to sit here and see all these threads pop up about Sweet Spot vs POL and which is BETTER. As the study indicates, and Friel talks about, each methodology can work better for a certain type of athlete. There isn’t a magic training methodology that we should ALL be following.
If you’re hitting a plateau, change it up. Maybe you need some HIIT, maybe you need some POL, maybe you need some rest. Change it up.
On past 9-10% grades (long ones, 1-2 miles) its solid sweet spot to upper threshold work to stay above 5mph with 34x32 gearing at 60-70rpm and less than 3W/kg (~250-270 FTP and 95kg). Looked at this one and it made me want to go back and climb Mt Fig again! If I drop down to lower tempo the speed falls to ~4mph. This year I’ll see how it goes with 34x34 gearing. I love these long and slow medio climbs, they have been great from a training point-of-view and the views are incredible
I’m running a 34x32. Is it easy enough to fit a 34 cassette or would it require new cables or adjustments or anything? I ride 105 with a long rear derailleur.
you can try it and likely will work. I upgraded to Ultegra 8000 and the shifting improved with the new derailleur.
I’ll give it a go 
worst case you buy a new rear derailleur. My 6800 series rear was a little banged up from a couple crashes and bike falling over at coffee shop.
For a month or so I was running 34 and 53 chainrings up front with 8000 and it worked just fine.
Aha, thanks for pointing that out! Still new to intervals.icu. Lazy to fix it for now (it was 20ish minutes above LTHR) not too bad for the first attempt. However, it felt little bit too easy and I had to start really hard.
@simonicusfacilis, @Sonny, @iamholland: 3W/kg, 9-10%, 70ish cadence. It just depends what one calls reasonable cadence I guess And gearing is semi-compact 36/28.
Ah. I am on 39 x 28. No ways I am doing 10% Z2 with that! Steepist climb near my house is 9% for 3.5km so guess thats ok
Is there any documentation that points out at which intensity the Ronnestad “15 seconds recovery valleys” are supposed to be done??? I think in this video at some point he says that the 15 seconds should be done at roughly 50% of the 30sec intensity spikes. So for exampe 65% of your FTP if the spikes are done at 130%. I can´t find the exact spot in the vid at the moment.
This seems too high for me and would also not be fitting to the rattle snake workout (40% valleys). But maybe I´m mistaking…!?
I read a lot on intervals, from TR forum, Seiler and Ronnestad protocols, this is really interesting.
So I decided to give it a go.
I have successfully finished Brasted last Tuesday, despite I did Mills+1 earlier the same day… Workout was hard but only spent 2.5min in HR Z5 (>90% HRMax)
Today I have tried Rattlesnake+2 expecting to kickstart HR but it struggled to raise in HR Z5 during the entire workout. I have raised intensity during first set from 100% to 103%. Done second set at 103%, 3rd set at 104% and last set at 105%. It was hard, but still HR only spent 29 seconds at 90%Max during the entire workout.
Note my doubled HIIT day impacted my next HIIT workout on Thursday 
I will avoid any doubled HIIT days now
Now I am thinking longer workout may be more appropriate to me in order to get HR longer over 90%Max. I will give it a try on Thursday, if I succeed to recover properly.