Backpedal vs Scale down workout

This mornings workout was Avalanche Spire +3 and during the last three intervals I had to take a breaks by backpedaling. I am not disappointed because I am finishing up a cold (hopefully). My question is it better to take a short break and continue the workout at 100% or to scale down the % and not take the break. I am sure this will happen again in the future and wanted to hear what others do. Thanks

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This is covered in a podcast that I need to find and boil down to a handy list.

I have the same question. Usually with VO2 max intervals I find I can do well enough on the first ~2/3 of a workout but then fail mightily on the last ~1/3 if I leave it at 100% intensity. I suspect it’s much better if I can do whole intervals at 95% than to use 1-2 back-pedals at 100%. I no longer have time to listen to podcasts, but I’d love to hear the podcast portion where this was discussed!

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This is a great resource for starters.

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Yes, better to reduce intensity.

My notes from recent podcast where training at VO2max is discussed:


My only comment on this article is on the intensity reduction section; the articles states “this bailout falls lowest on the list of recommended modifications since you might miss the overall objective of the workout.”, while it is a recommended way of adjusting VO2Max sessions (up or down) to ensure you can successfully complete the intervals, while still staying within the VO2Max range, and this recommendation is repeated in the text of most if not all VO2Max sessions. It would probably be more exact to say something like “unless you make sure your workout intervals remain within the required range for the type of workout you are doing, this bailout falls…”

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That is a good observation. Maybe @Bryce can review the comment and consider if an adjustment is appropriate?

Hey everyone!

In general, it is better to maintain the prescribed intensity by taking a quick backpedal mid-interval. If a backpedal or two isn’t cutting it, then drop the intensity. When reducin intensity, you can drop up to 5%, but if you reduce any further you will start to lose the intention of the workout.

If you feel the need to reduce more than 5%, even with brief backpedals mid-interval, then your FTP may be too high, or you are attempting a VO2 Max variation that you aren’t ready for. You can always do -1 versions of the workout if neccessary.

I hope this helps!

Hey Bryce let me try to explain the problem with that general recommendation for some of us… starting with this TR blog post about VO2max workouts:

In comparison to VO2 max, your FTP generally falls between 78-85% pVO2 max, with pVO2 max falling around 118-128% FTP. This is the reason why VO2 max workouts from TrainerRoad use 120% FTP as the basis for short, intense intervals. Erring near the lower end of the spectrum, these workouts allow you to do more work while still at a very high percentage of pVO2 max. That’s what really matters — spending time training at high percentages of pVO2 max.

(except the recent podcast 191 VO2max deep dive part 2 clarified what really matters is spending time at high percentages of max aerobic uptake)

  • vo2 target of 128% ftp = 1/.78 when ftp is 78% pVO2max
  • vo2 target of 118% ftp = 1/.85 when ftp is 85% pVO2max

What happens when you fall outside the norm, and “erring near the lower end of the spectrum” is still too high?

Lets run some new numbers… This year partly due to focus on non-cycling knee rehab, my pVO2max dropped like a rock and is uncomfortably close to ftp. Last summer my ftp was something like 85% of pVO2max, and this year ftp has been hovering around 90% pVO2max. One indicator of being in this detrained pVO2max state is a failed ramp test.

Doing the math when ftp = 90% pVO2max:

  • vo2 target of 111% ftp = 1/.9 when ftp is 90% pVO2max

so for all outliers with low “field/workout tested” pVO2max relative to ftp, erring near the lower end of the spectrum means reducing target from 120% to 111% if ftp = 90% pVO2max. And then during the workout your 5% reduction comment applies.

p.s. I’m using failed ramp tests as a leading indicator that pVO2max is falling too close to FTP, and a follow up “repeatable power at vo2max” workout is required. Once pVO2max is detrained, it is time for a vo2 booster block to get back on track.

Hmmm, yes, but that does not match with coach Chad’s general guidelines in VO2Max sessions. It’s not really important however.