What is “the right amount” of power decline, or HR or RPE increase?
Make the power, and VO2 will follow. What do you hope to gain by making it any more complicated than that?
Serious question as you seem to have a lot of knowledge on this stuff.
When I do longer (3,4,5 min) intervals I find power drops towards end of interval or on the later intervals even though breathing very high, HR at/above 95% max and RPE at 11 out of 10!
When is it time to stop…I.e. even though RPE, breathing, HR v high if cant hold (say) 105% FTP is it time to just stop as power not high enough for v02?
Where is the limit? FTP, 105%, 110%?
Adding an example to make it more clear the problem I have with constant power intervals.
Interval #1. Heart rate average less than 90% of max. I’m making the power, but doubt I’m at VO2max.
Interval #6. Half way through the interval I can’t make the power and have to stop.
Seems like a suboptimal approach to train for VO2max.
As some additional context - in case its not obvious, my anaerobic capabilities are relatively a lot stronger than my aerobic capabilities.
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How long are (were) your intervals?
If they were at least 3 minutes, I wouldn’t worry about your HR being less than 90% of max. Your VO2 had to be up there.
Could the difference in RPE/HR early in the workout be accounted for by higher contributions from anaerobic energy?
Possibly related, I feel lactic accumulation following the first interval of a vo2max session with steady intervals (>= 3 mins), even with a seemingly adequate warmup of low intensity + 3 x 60s @ target power. Thoughts?
Oh I wasn’t commenting on your workouts, I meant to reply directly to @evrevzbcm since they had declining power targets and gaps, and said that was all they could handle, and maybe not even that. If you can’t handle the power for the required duration then you’re going too hard, simple as that. Well, either that or you’re too fatigued and need to shorten interval length. But yeah if you’re fresh…
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I search the thread and didn’t see anything, but has anyone looked at the results of this study?
https://www.researchgate.net/publication/336641479_Optimizing_Interval_Training_Through_Power-Output_Variation_Within_the_Work_Intervals
It’s interesting that it uses a hard start idea but essentially repeats the hard efforts of 30s 3 times during the interval with easier periods between. Looks like the time >90% vo2 max was greater than the steady intervals but the RPE was lower. The efforts were described in terms of MAP, and I’m not quite sure what that means in terms of FTP for most people, but I guess it can probably be determined without too much difficulty.
It might offer another alternative approach to add to the toolbox - steady efforts, hard starts, short bursts and now variable intensity intervals. Has anyone tried these?
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Indirectly. Power falls due to willpower / fatigue. Beat myself and go more, shift into a harder gear and maintain cadence.
Many ways to skin a cat. Seems to me like the most important thing is keeping the blood lactate levels high enough that you need all the oxygen you can get, how seems less important
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There was an interesting observation by the study authors suggesting the recruitment of more muscle in the 100% MAP efforts increased oxygen demands that lasted over the entire interval.
These were also very structured variable intervals with more significant variations in power, rather than a more fluctuating approach we’ve probably all experience as we get fatigued:
30s 100% MAP
1m 77% MAP
30s 100% MAP
1m 77% MAP
30s 100% MAP
1.5m 77% MAP
rinse and repeat for 6 x 5m
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It has nothing to do with lactate. The key is to keep the demand for ATP high. The easiest way to do that is to not let your power drop too much for too long.
This is another variation to add to keep vo2max intervals interesting.
Vo2max intervals are hard (or should be). So anything you can do to increase motivation helps. And variation / trying something new is one way to do this.
In this study, they measured time at >90% vo2max. The best measure of effectiveness of different vo2max interval formats is power for some duration, or time trial performance. If I recall from some podcast or other that I’ve listened to (might be the TTS podcast with Michael Rosenblat), different vo2max formats can have the same impact on measured vo2max, but differing impact on power at vo2max. The consensus seems to be that longer interval formats (greater than 4 mins) are more effective vs shorter at increasing power. The intervals in the linked study above probably fall into the “long” category.
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yep - it was interesting that this study didnt end in some form of performance test but simply measure time >90%. vo2 max. Although it does seem that time >90% is seen as a reasonable proxy for measuring effective vo2 intervals?
I guess the bottom line was that 5 mins variable pacing had greater time >90% vo2 max than steady paced for the same duration, so adding these 100% MAP efforts may be a good way to boost effectiveness?
Also makes me wonder about the potential to use the same approach in threshold work - longer intervals at 95% FTP with short bursts up to 130-140% etc. I know lots of people use these already but maybe its actually a more effective stimulus for threshold work as well?
Rambling a little…sorry 
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This is a variant of over unders. I do something similar in some of my SS workouts.
The goal with the power spikes is to get more lactate into my system, and work on clearance. These SS over unders are more sustainable for me than threshold over unders.
Doing workouts like this also add some variation, vs just doing 1x60 at a flat 90%. Keeps things more interesting.
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I was also thinking of how it might change the stimulus from threshold bursts eg 95% FTP with 15-30 sec spikes well above the usual 105% of o/u’s? Would that perhaps push HR a little higher, increase the vo2 kinetics and push these workouts to a higher stimulus while the RPE stays more like a threshold session? No idea…
I think changes like this are likely to be marginal variants on a typical threshold OU session.
Yes, you may go to 120%+, but you’ll do that for a shorter duration vs going to ~105% like in a traditional OU.
I personally avoid threshold workouts. I find they put me in a hole from a fatigue perspective.
When I want to work on muscular endurance I do sweet spot workouts. And when I want to work on VO2Max, I do VO2Max workouts.
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It’s not.
For an untrained individual, even continuous, moderate intensity exercise at anything >50% of VO2max will provide a significant stimulus for increasing VO2max.
For a highly trained athlete, VO2max may not be able to increase any further no matter how hard you train.
You therefore can’t just set an arbitrary point such as 90% of VO2max and declare it effective (or ineffective).
What can be said, however, is that intensity matters - in fact, intensity (up to 100% of VO2max) appears to be a bigger driver of adaptation than anything else.
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I can see that - what would be the measure of ‘intensity’ in that then?
If spending time doing 5 min intervals and 1 approach yields more time >90% vo2 max at lower RPE than a steady effort, would that not suggest it’s a more effective way to create that intensity?
Perhaps, but maybe you really need to be training at, say, 95% of VO2max to get any benefit.
Think the guys in group 1 of this study would have experienced any significant improvement by doing intervals at 90% of VO2max?
Kolie Moore was on the Endurance Innovation podcast - the topic is VO2max. I thought it was a great podcast. It fills in a lot of details and is much more accessible as it’s not biochemistry heavy.
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Thank you for the link. Really great podcast and some new parts of wisdom from KM that I have never heard from him. Definitely worth listening.
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