http://www.trainingandracingwithapowermeter.com/...using-power.html?m=1

ETA: Not only does WKO4 include a function to make it easy to calculate an exponentially-weighted moving average, it can also estimate your VO2max to within +/- 2% (in average), and from such values estimate the percentage of VO2max required throughout any workout (e.g., 30 s on/off intervals as described in the article above). For those without access to such advanced tools, though, all of the lessons from this old article still apply.

Tha k you for chiming in I was hoping you would. Only reason I asked is because I came across this: https://www.wattkg.com/short-intervals/

Seems similar to USRPT maybe?

Trainer road gives you a mix of both.

It does- their oly plans and above however are all 3min v02.... in fact they rarely deviate away from that

Even if you are going really hard in the beginning of each interval, it still takes 20 to 40 seconds to bring yourself up to a level that stimulates adaptations at VO2max. If you are doing 1 min intervals you get a very short time at the correct level.

You didn't specify what the rest period is. If you shorten the rest or keep the rest period at a higher intensity, you may be able to bring yourself back up the the correct level quicker during the subsequent intervals.

So 5X5' with 5 min recovery would get you ~4 min of stimulation for the first interval, depending on how you did your rest you may get 4:20 to 4:40 worth of adaptation for the last 4 intervals. ~22 min at VO2max

30X1 with 1 min recovery would get you 20 to 40 seconds of stress for each interval if you went really easy on the recovery, 40 to 50 seconds if you kept your effort higher near threshold.
~15-18 min at VO2max

Obviously there are other things happening at that power level as well.

https://journals.plos.org/...journal.pone.0073182

A quote from the link above: "The conventional wisdom is that intervals of 3–5 minutes are especially effective in evoking increases in exercise capacity. Consistent with this idea, the nine studies that generated the biggest increases in VO2max (∼0.85/min) generally used intervals of 3–5 minutes and high intensity continuous training."

(Not a reply to Dr. Coggan)

This review is about "subjects [that] had to fall within the range of untrained/sedentary to recreationally active" to be included and their VO2 values ranged from ~26 - 52 ml/kg/min. I didn't see the mean VO2 listed, but assuming it's somewhere in the middle of that range...you don't have to get picky about what you do to improve. The whole point of this thread is being picky. Spartacus doesn't sound like a duffer on the bike.

The subjects in the Rønnestad study linked a few posts above had a mean VO2 of 66 ml/kg/min (not low!) and their training was interspersed with low volume. That probably translates a little better to the OP. When 'time at intensity' is equal between groups, it *seems* that the awful looking shorter intervals with appropriately shorter rests should not be overlooked in favor of the often regurgitated 3-5 minute Z5/Z6 sets. My career path has changed and I don't really keep up with this stuff though, so Dr. AC may have a handful of links to smack that down though.

And anytime I see "Hickson" my legs and stomach start to quiver.

I used to prescribe short on/offs quite a lot. We were all Billat fans. Athletes loved it, easy on the mind. And you see progress quickly, those on wattages go up fast.

However, this progress in training rarely translated into better race results. I came to the conclusion that one crucial aspect is missing: building mental toughness. 3-5min intervals are tough. And for many racing scenarios they are specific. How often do you go 30s hard, 30s easy for 20minutes?

It's this suffering that's missing. And in the dark-red zone mental toughness is key. And one has to train it, raise the suffer threshold. You may perform better on a graded test in the lab but out there, I don't know.

These days I only use them for building fatigue resistance like at the end of a long workout.

But what do I know ....

What about say 1:15 - 1:30 on with :20 complete rest, how would that be?

If you mean stopping completely between each interval, on a trainer your wheel would stop and you would waste time trying to spin it up and risk slipping the wheel on the roller. Personally I think you would waste 20 second just spinning up then take another 10-15 seconds to get into the zone so there would be 30 seconds wasted and then 45-60 seconds in right zone. If you kept pedaling really easy to keep the rear wheel moving you'd probably not waste the spin up time.

On the road you'd probably wouldn't need 10 seconds to start up so you'd probably get 60-65 seconds of work done.

That's just my thoughts, I've never tried it. I could be completely off base on this one.

You could do an interesting experiment and see how long it takes your HR to respond to increases and decreases in power. That may help guide you in that training.

As stated in one of the links AC provided, a person would probably put a lot to time into quadrant 1 and 2 so if that's what they needed, it may help them.

I did some 40/20's here
https://connect.garmin.com/.../activity/2772633464
and here
https://connect.garmin.com/.../activity/2824369567

You can see how little my HR went down with a large reduction in power for 20 seconds and how quickly it came back up. The power goal was way above what I was capable of so I was just going as hard and evenly as I could.

For me, HR in the 150's is really hard

I think that should tell you something right there.

Exercise at/near VO2max is an extreme physiological situation, as evidenced, e.g., by the fact that plasma catecholamine levels will be several fold *higher* than in someone who just suffered a heart attack, major traumatic injury, or significant burns. If you want to really drive up VO2max, then sooner or later you have to be willing to suffer. You can try to game the system by manipulating the work:rest ratio, but there really isn't any good evidence that this is superior to just tackling things "head on", i.e., by exercising at/near VO2max over and over again.

TL, DR:

PPP: Sooner or later, you have to increase the power.