RPE for micro bursts?

I struggle to find out, if my case is normal, or I have some weakness I should take care of. AFAIK:

  • heart rate and Vo2 intake pretty much correlates each other
  • micro bursts are just easier version of doing VO2 max intervals
  • that means, at the end of a well executed VO2max interval or micro bursts set, the heart rate should be very high

HR can be affected by lot of things, but I see descripted behaviour for few years now:

  • my max heartrate is 204, threshold heart rate around ?180?
  • I have big trouble finishing 3 min VO2max intervals (for example Kaiser) on 120% FTP, usually I need to decrease intensity (mostly to 115%) after first two intervals. My heart rate at the end of intervals is usually less than 190 bpm.
  • I have big trouble increasing heart rate while micro bursts. Usually I am overriding workount intensity to 105-110% while doing micro bursts. Heart rates at the end of the sets are around 180 bpm. Today, I did Bluebell +2 on workount intensity 105% and average HR at the end of the intervals was 173.
  • breathing while doing micro bursts is very heavy, legs are burning
  • my powermeters are calibrated and precise

Why is HR low when bursts gets though and breathing heavy? Why do I need to increase workount intensity while doing micro bursts, but I need to decrease intensity for 3min intervals? Is that expected behaviour? Should I train and monitor some aspect of my performance?

Anaerobic contribution is allowing you to bump up intensity.

Heart rate is being limited by the longish 1 minute recovery intervals in Bluebell (1:1 work to rest).

Try 30/15s like Rattlesnake.

What’s your cadence?

Difference in motor unit recruitment?

yes, I see anaerobic contribution, after first sets of micro bursts at 100% workout intensity my heart rates are at sweet spot zones… My usual cadence doing vo2max workouts is around 105 rpm.

I looked into my calendar, but did not find micro bursts at 2:1 ratio, all of them is 1:1. Probably they are not in my plans (targeted for MTB marathons). Is it better to shorten recovery than increase intensity?

The heart rate lags for micro bursts. Vo2 is always hard to do. How exactly are you riding a vo2 effort

Both ways are equally beneficial.

2:1 maximizes time at VO2max. This is generally the purpose of the Build phase.

1:1 with higher power increases repeatability. IMO there’s no substitute for 15/15s like Spanish Needle and Gardiner. They’re really good for helping you deal with the accordion effect in the back of a drawn out field. This would instead be the purpose of the Specialty phase.

When looking at metrics, the former might give you increased power numbers at various time intervals, e.g. 1min, 5min and FTP. The latter might not increase those numbers as much, but on a given ride, your NP/IF might be higher.

Your experience with longer VO2 intervals sounds a whole lot like you are lacking strength endurance.

I have experienced the same as you do. Short efforts such as 30/15s and the like wouldn’t get my heart rate high enough. Pretty much the reason why I switched to 2-3 minute efforts at 120% or 4-8 minute efforts between 108 and 112%. Though doing those takes some time and preparation. Which brings me back to my initial statement. If I were you I would do sustained power build. That will likely do the trick for you.

That is exactly my feeling for years! However:

  • after 4th executed Sustained power build phase I did not measure any progress in FTP, again as at previous ones
  • sport doctor after lactate tests told me I have very good lactate clearing ability (but don`t know relative to who). Build phase shoult train also lactate clearing ability, sweet spot is more focused on lactate production, right?
  • I see FTP progress mainly after SSB 2, wchich AFAIK is the phase to increase strenght endurance. About 10 W, currently I am about 4.1+ W/kg

Last 4 weeks I experimented, switched second part of my Sustained power build phase to SSB 2, but choosed workouts that will match TSS from build phase workouts. It was not easy, I feel stronger, but Ramp test next week will tell more.

Was it bad idea?

I get it, having a high FTP is nice and seeing it progress even more. Though I wouldn’t measure all progress via that one metric.

Anyway, bringing this back to your initial question: You provided heart rates and explained that short VO2 stuff doesn’t bring your heart rate up high enough. You also explained that you fail to do longer intervals. In my opinion there are three ways to tackle the issue(s).

(1) Do some anaerobic efforts before starting your short intervals. Also adjust the ratio work/rest ratio. So more work and less rest.
(2) Increase duration to 2-3 minutes at a high percentage (~120%).
(3) Increase duration to 5-8 minutes at a moderately high intensity (108-112%).

It might take some time but whatever you do, you will be able to solve the problem. After all we are all different. So it’s up to us to figure out what works best for us.

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micro bursts should be all out, google tabata intervals, etc. More Zone 6 as opposed to Zone 5, but you get the Z5 adaptations according to Dr. Tabata’s literature.