From what i could find:
4x16 is in zone 2 (80-100% FTP), so Tempo / Sweet spot / Threshold
4x8 = 108% FTP
4x4 = 120-105% FTP
30/15 = 120% FTP
However, the right % of FTP is actually as hard as possible but not too hard so you cant complete the interval. For example what i do with the 4 min intervals, i start at 120% FTP and just try to maintain as much as possible, which means my power will drop, but the whole point is to have you working at a high percentage of VO2max. So even if your power drops, maybe just increase cadence and just try to ride the interval out and keep that heartrate and breating at the point that matters.
And if youre doing a 1 hour workout, 4x4 leaves a lot of time unused, so i make it 6x4, why not.
He doesn’t. The aim is to ride at the highest intensity you can manage for all four intervals. So you need to experiment to find the answer for yourself.
Indeed, you should always be developing and learning. Things don’t need to be perfect to have an impact. Repeating for a few weeks really helps you see what power you can hold.
I think is easy to get too fixated on ERG mode and riding at fixed power. I only have power indoors on my indoor trainer.
Imagine you’ve got 4 hills to get over. It takes 2 minutes to descend each hill before climbing the next. Each hill takes between 7-9 minutes but if you go hard on the early hills you will fade on the later hills and overall it’ll take you longer to complete.
The pacing you are trying to get right is a bit like this. You are trying to achieve the highest average power across all 4 hills. It’s another way of saying the highest average pace. This means not going too hard on the early hills as you’ll fade badly later on.
Try the workout not in ERG mode. You may surprise yourself and how you workout the pacing.
I believe that Seiler says to “solve the equation “. Each of those intervals are done as hard as you can. I believe he also talks about accumulating time at 90% of HRMax.
Here’s some advice after spending last season doing various high-intensity workouts in a polarized approach. None of this is scientific or based on anything other than my own observations.
There are a few ways to get an idea of whether you’re truly operating at or very close to VO2 max. Heart rate is part of the equation, but your respiratory rate is also a great indicator and I believe both should be used to determine your goal intensity, not just % of HRmax.
Hard-starts are an awesome way to expedite the above. I found that it takes me anywhere from 60-90 seconds to get to what I believe is VO2 max. You might only accumulate 3 minutes of TiZ in a 4-minute interval. Take this into account when factoring in TiZ targets and progression.
Throw target-wattages away when doing micro-intervals, also throw ERG mode away and ride them au-naturel. Just go as hard as you can for the 30 seconds or whatever it is.
Power targets can be helpful on longer intervals so you at least have an idea of where to start
Don’t do the same workout more than 2x w/o either changing duration or power, always be progressing
These workouts are hard and very demanding both mentally and physiologically. If you’re missing power targets or RPE seems unusually high and things just don’t feel right, it’s ok to shut it down. Doing 4 minute repeats at threshold is not benefitting you if you can’t hit your VO2 power. Know the difference between mental weakness and some sort of physiological limitation.
Schedule regeneration/rest/recovery weeks. I like to do 3 on 1 off (off meaning, a light/easy week…not actually one full week of no riding). This gives me a mental (and physical) break from the demands of VO2 work.
If you have any questions I’m happy to answer them, I did a lot of polarized training last season and I loved it. My bread and butter VO2 work were in the 3-5 minute variety, but some 30/15’s were done indoors on the trainer and were also excellent.
Same here. How important are the recovery periods between the intervals? Do they matter a lot? Say you want to do 4x8min on some local climbs, but recovery depends on the road between those climbs. Is this a problem when not all ‘recovery’ time is equal? Say between 4-15min? Or just focus on time above 90% when doing the intervals on those climbs?
If that’s the nature of the hills, that’s the nature. Shorter recovery means you get up to that 90% VO2 max region quicker. You want enough recovery that you can work that next 8 min hill. But even if you’re getting longer recovery between you will still be accumulating time at a high percentage of VO2 max. If you enjoy doing it that way and it motivates you to do it consistently. Then go for it. You’ll know if it’s getting you fitter or it’s time to try something different.
The only thing I’d note is that recovery time does affect the power output. I have done these with 4 or 5 minute recoveries (can’t recall which) and completed all 4 at an average of 299W; when I did them a couple of weeks later with 2 minute recoveries, I did the first 3 at an average of 298 but couldn’t hold that longer than 6 minutes into the last one.
Mind you, tbf I did the 4-5 minute recovery ones outdoors, as old school hill repeats, and I’m always a touch more powerful outdoors, so that may have been a factor as well.
Maybe start the first min of the climb somewhat harder to get to the 90% sooner? And then keep the power more steady (around 102-106%ftp?). And monitor the heart rate to keep it above 90%? Or should I aim higher in power target? But in a 8min effort at around 105% FTP, total time at vo2max would not be that bad I guess?
FWIW, want to start a 6week polarized approach with Z1 work and 2 vo2max sessions a week (30/15 and 5-8min intervals outdoor on some climbs?
Working a bit harder on the lower half of the hill for the first minute or so certainly won’t do any harm. Just don’t overdo it.
I don’t use power outside. I do have a pretty good idea on pacing and where it’ll take the HR. I wouldn’t worry too much about power up the hill. Keep working and watch your HR head up towards that 90% figure. As you close in within a few beats back off on the effort but not too much.
If you haven’t already you’ll gain a view on how quickly your HR climbs for a given effort and know what pace to aim for, for your 8 mins or so.
For 8-minuters I’m in the 4-minute rest interval fan club. For high VO2 work like 3-5 minuters I’m doing 1:1. If you were targeting max power you’d probably want to go 1:2 (4 minute on / 8 minute rest).
That’s interesting because I think the original study only had 2 minute rest periods in between. The two minute rest period is something I have heard elsewhere as being a common approach. Fully accept that for max power efforts you are looking for complete recovery between efforts though.
That’s simply not enough rest for me so I did 4 minutes of recovery. You want to be able to complete these intervals, resting for a mere 2-min doesn’t allow me to do that. You could certainly experiment though…
FWIW, I also do a 30-second hard start on these to get HR elevated quickly.
I have done a lot of intervals with a 2 minute rest over the last couple of years, but recently introduced 4x8 to my repertoire. It’s not easy and when I have done the majority of them out of racing season my FTP has not been stable so it is hard to put a figure on the intensity. But I have got good at pushing myself to get through the later intervals. In my last 4x8 my heart rate at the start of the interval increased from 119 for the first to 132 for the last. At the end it was 152 for the first and 172 for the last. I was able to increase my power on each interval too. I think I could have probably increased the intensity of the first interval, but was really pleased with it as a workout.
The 8-minuter’s are interesting and require more experimentation with regard to power output and modulation. If I do them indoors I’ll do the main interval at 105% of FTP and go from there. When I was doing them I found that it usually took around 90 seconds to hit 90% of HRmax.
The hard start really helps get that heart rate up quicker so you spend more time in that 90% or higher range.
Ive started doing 8 min intervals recently on a polarised model, using long rest periods still (about 1:1 work to rest), gradually trying to reduce them though
I average about 90% max HR for the 8 mins, takes me about 2mins to reach it using a steady power for the interval
So far i am feeling improvements, and holding a bit more power for my 8 mins. Ramp test at the end of this 4 week block will tell me for sure. This is the 2nd 4 week block of trying out polarised for me, lots of zone 2 which im enjoying, gives me good opportunity to work on my TT position on the road