We’ve mentioned this in our podcasts. It’s ok the toss in a Bullet with Butterfly Wings or Spinning Walls or Adventure of a Lifetime in place of your standard low intensity workout:
https://www.xertonline.com/workout/ngc9lal4p6vifzsu
https://www.xertonline.com/workout/6sjivxpsrdqffqr8
https://www.xertonline.com/workout/3qzq9bd4af1642ex
Interesting that the literature seems to suggest longer “sprints” than those currently used in the Xert Library. In the article that you’ve mentioned above, as well as a published article that I touched on last month in Pez Cycling News also used 30s sprints in their protocol.
Using the study above, I created my own #MIXEDMODE workout that follows the general format outlined in the study:
I found that the 30s sprints were very difficult, much harder than I was originally anticipating. Executing the workout perfectly as defined should have resulted in a Road Sprinter focus (1:38), but I was only able to manage a Puncheur focus (3:34):
I may give this workout another shot in a couple of weeks and see how it goes.
Only 14 days and done with “elite” cyclists.
You could think of this as confirming that signature (or fitness) decay is relevant & useful. After just 2 weeks of a LIT camp, there was already a 4% difference in Sprint Power and 5 min power between the group that did only LIT and the group that added sprints into their LIT training. “Use it or lose it”, haha.
Just a thought 
30s efforts have relatively similar high and peak strain and so can be quite taxing.
Hi @ManofSteele, I have created some similar LSD sprint workouts, and my setup wasn’t transitioning back to erg mode after the sprint, it seemed to be stuck in a 3% slope following the sprint. Do you have any suspicions why?
Which app are you using?
Xert EBC for Android
Which version?
Version 4.2.4.1
It’s ok the toss in a Bullet with Butterfly Wings or Spinning Walls or Adventure of a Lifetime in place of your standard low intensity workout
If I pull “Bullet with Butterfly Wings” in my planner it renders me yellow for almost a week. In comparison with the endurance workouts which leave me in the blue.
So this would basically prevent me from doing e.g. my climber workouts which are specific to my focus type.
I wonder how can this be “ok”?
Yup! This is how the platform works - if you only only only ever do low intensity endurance rides, you’ll never be yellow status (yellow status indicates that your high/peak systems are fatigued and need to rest).
If you’re in a base period (where you aren’t doing much High Intensity), then it doesn’t hurt to throw in some sprints, since (I assume) you’re doing predominantly low intensity training anyways. That’s the idea here. If you’re already doing other HIIT work, then this may not be a viable strategy for you.
As your high/peak training loads grow, you’ll be able to recover more quickly from those efforts. IOW, as you add more sprints/high intensity training into your training, you’ll actually be able to more quickly recover from those workouts. For example, at the height of your outdoor season, that same workout might only put you in the yellow for 2-3 days. Hope that makes sense.
Thanks Scott, with that bit of context you added the above statement makes sense.
As @ManofSteele mentions it’s going to depend on your current status stars count and TL intensity distribution. but try dropping Bullet further on down the line and watch what happens when you pretend to skip days in between.
In my case (currently at 3 stars) I’ll see anything from 3 days yellow if dropped on today versus only on the day dropped if I place it on the second green day in the future. YMMV
Just to be clear (and in fact to double-check my understanding, as I have a doubt now ), my read of documentation is that it’s not the total trading load (3 stars or whatever) that drives how long it takes to recover from high intensity, but specifically the high and peak training load and form, given they are each tracked independently. That’s how I interpret this page anyway
So you could be 5 stars, with it all being low training load (zero high and peak), and it would take just as long to ‘recover’ from a sprint workout as someone with 1 or 2 stars (also with zero high and peak load). Anyone starting with zero high + peak training load that added say 10 XSS of peak strain would then have the same (negative) peak form, and then require the same amount of time for form to recover to be >0
Suspect @ManofSteele will correct me if I’m wrong
Hi ridge,
I’d assume that your “high/peak training loads” is then higher than mine.
With Scotts statement I just even discovered that training load is distributed between low, high, peak, I wasn’t aware of that before.
I am also around 3 stars, but looking at the charts its distributed like
Low TL: 73.1
High TL: 0.6
Peak TL: 0.1
Indeed, lots of low intensity for me. That matches pretty much what Scott says.
Therefore no sprints during endurance rides for me and rather doing my climber workouts a bit more consistently.
Here for more than a year and still learning…
Indeed, we understood it the same way.
You’re exactly right. This is why it doesn’t hurt to throw in a HIIT workout every once in a while even during the winter/base period.
Here for 5(?) years and still learning too 
How should we interpret the low power intervals between the sprints in Bullet With Butterfly Wings? This is how it looks for me.
A zone-based system has the other workouts in my active recovery zone (60-80% of LTP) whereas 100-120% LTP would be in my endurance zone. Training with FatMaxxer and keeping DFAalpha1 > 0.75 also puts me at 100-120% LTP for power output. Would these workouts be too low intensity? Is my LTP possibly too low for what the workout is prescribing?
Is there any literature on how long it takes the body to switch from carbs back to fat after a sprint?
