Pacing Breakthrough - Advice for new rider / erg conditioned?

Coming to try out Xert from last year of TR and then this base season of a bit of unmotivated training on Zwift. I was training on Zwift on a set FTP and because I was on TR last year I didn’t really have any major capacitive efforts, instead relying on TR’s AI FTP. I have though pretty much relied upon Erg mode all year (to my detriment sometimes!)

I’m going to start by doing “A Pain” following reading a few forums, but as someone used to erg, how should I pace this?

3 sets of 13*30/15s. Am I pacing to hit the highest sustainable “on” power for the whole workout? This would mean trying to hit about 400-450 evenly. Smashing every 30s interval as hard as I can - maybe first one @ 800+, then suddenly falling off a cliff? Starting steady (380 - what xert wants me to start at) and then saving for one or two capacitive efforts close to the end of each set? Can I do any of these?

I just want to adjust the xert engine to my physiology as fast as possible to get appropriately difficult workouts as fast as possible.

Before you jump into “The Pain” :grimacing: I suggest you review my Onboarding post for newbies and trial users.
Onboarding steps for Xert Trial users and newbies - General - Xert Community Forum (

Also, consider one of the Fitness Test options in the Workouts Library as an alternative to the Ronnestad micro-interval approach. Search for “fitness test” in quotes.
I suggest riding any Breakthrough test workout entirely in Slope mode, exceeding targets if able, and be prepared to spin up (stand if you want) and go for broke on any longer interval designed to be ridden to failure. Right before you are about to fail, try a max sprint effort for at least 5-7 secs.

The reason for Slope mode is to ensure you can fully express your fitness signature. While many hard workouts can generate BTs, if your signature is understated the workout will be too easy in AUTO mode (ERG control). For example, one way to know The Pain That’s I’m Used To wasn’t tough enough is if you get through all three sets intact and feel you could have done more. Instead, you should feel spent during one or more sets and may not complete all three.
If you do decide on The Pain how you ride the first set will tell you what’s required for the next two. :wink:
Another reason to do the entire workout in Slope mode is smart trainer responsiveness during micro-interval transitions. This isn’t a factor when you control the resistance with gears/cadence.

I did read the guide; I took Option A - I have about 6 years of training data that has pulled over, indoors and out, but as I have no capacitive efforts since the Gran Fondo World Championships last September there is a lot of decay (50-60 watts off my threshold, about 100-120w off my 4-5min, and 500w off my peak).

I wanted to do “The Pain” because I’ve just taken a recovery week and want to train and have time to train on Monday, not just to test and the breakthrough workouts are all very low TSS with one cap effort - I dislike doing these in week-to-week training which is why I stuck to TrainerRoad last year.

I am content with the concept of slope mode - but I suppose I’m asking about pacing a workout to normalise my profile. There is a difference between pacing a set of vo2 intervals in slope mode and doing a timed capacitive effort.

A couple things to consider –
Your Power Duration Curve in Xert is actually a combination of theoretical and actual power performed. IOW under the ideal conditions your performance under pressure indicates you could achieve indicated values on your curve.
Peak Power, for example. is typically power meter based but that value can get bumped up from a max effort expressed during MPA drawdown where you are well below your 1sec power.
The primary component to signature validation is measuring your performance under fatigue.
This article best explains the ways signature values are extracted during activities and why a paced effort like a RAMP or 20-minute test isn’t required.
Breaking Through the Xert Way! – Xert (
Also note with the latest signature algorithm updates (Nov 2023) suggest leaving the decay setting at Optimal for best results. Signature adjustments will occur without frequent BT events.

As far as BTs go, you are just as likely to generate one on a tough workout, ride, or virtual race that includes moments of maximal efforts under fatigue.
See this topic for a variety of examples – Let’s See Your BREAKTHROUGHS! :boom: - General - Xert Community Forum (

With EBC Android there is the option to ride a workout, end it, select another, and keep riding to record multiple workouts as one activity. OTOH there is nothing wrong with multiple activities to reach a particular XSS goal for the day.

I appreciate your continued effort - but this is why I started a thread. You haven’t answered any of my questions, and neither does any of the instructional media and/or pages.

In fact reading through the forums I can’t find a single thread where someone gets an answer to their question.

I even asked it a second time, but you ignored it again.

Apologies - it may be that nobody on here speaks English as a first language - and that could be confusing things.

I think I might just not have the patience for this, or it might be that the software only makes sense in another language or if you accept that you’re basically going to be an alpha / beta tester.

Thanks anyway

If all you want is to achieve a breakthrough you can do any, just needs to be failure / all out. It also depends which part of your signature you want to update most… if it’s PP and HIE go for the higher efforts (and breakthrough quicker), but if you want a better TP estimate you really want to draw down MPA over a longer time, so more evenly paced is better. Or do both, just not on the same day

Being in slope mode helps, as said, also to get a more ‘natural’ failure pattern.

Only other thing to consider is that quite a few users report inflated signatures from repeated on off intervals, myself included…though I haven’t checked since the latest updates… potentially something to do with how quickly /accurately different powermeters report the ‘off’ intervals (I.e, some may not adjust down quickly enough / over report rest interval power… which is fine for a few intervals but when you do 13+ in a row to BT I can see how it may distort things…). Anyway, I personally tend to only include longer / continuous efforts now (or flag those that are too ‘on off’)

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If you have concerns about riding workouts in slope mode vs ERG control it’s really not much different. Targets stay the same. Gears/cadence control how well you attain/maintain targets.
Yes, you will need to experiment by riding some workouts in Slope mode to see what’s required.
You want to determine which gears/cadence combo works best with your bike/trainer for high and low watts.
There isn’t any special pacing involved for breakthrough workouts. You either complete the workout as defined or you don’t. The important component for a BT is whether you can exceed MPA at any given point during the activity (workout or outdoor ride), how long you can exceed it, and how often.

So I did the 3x 13*30/15s. Initial asking power was 400, so I did the first set at 100%, second at 105%, third at 110-115% and a couple of sprints to bring my peak back up.

All very easy and manageable, HR didn’t get above threshold until the last set. It brought me up by 20ish watts on TP; still quite a lot low.

I’ll just let the Xert thing slowly adjust to my fitness I guess by overperforming on each of the intensity days I schedule.

I still just don’t really get when the workouts are expecting me to go all out on a set or pace it, or pace it so as to complete the sets.

e.g. Imagine a workout with 5*5@110%ish. Am i going into that trying to pick a power to sustain for 25 mins total, or am I going in trying to produce a 5min pb power in interval 1, or ramping for a pb in interval 5? If I spank out 500w for rep 1, I’m barely going to get above FTP for rep 2.

I’m so used to just being given a power to hit and focusing on that. None of the trainerroad workouts are set up for any variability in output.

This is a good question/thread!

The original Ronnestad study that used micro-intervals was prescribed this way (Iso-effort in the paper). Participants were told to sustain the highest effort they could across the entire workout. I can appreciate this approach in place of the more usual work-clamped approach, since (IMO) these sort of all-out workouts should be done by feel.

Other studies from Billat & more recently from Ronnestadt & colleagues will often mention “time above 90% HRmax” and/or “time above 90% VO2max” - if that’s the goal, then this 'fast start & fade approach may work well, since it will quickly accelerate your HR/VO2 towards 90% of max, and it will remain >90% even as the amount of power you can generate declines. To me, the constant elevation of HR/VO2 after the ‘hard start’ strongly suggests (to me) that MPA is a true phenomenon.

I’ve done many of these efforts over the years, having done a bit of each:

  • 30/30’s to failure… starting easy & progressively increasing my effort:

  • 3 x [13x 30/15] going as hard as I can out the gate & then fading later:

  • 3 x [13x 30/15] with Iso-effort, aiming to reach failure at the last interval or two of each set. When I can baaaarely reach MPA at the tail end of all 3 sets, that’s when I know I’m in top form. I’m most proud of these efforts - they’re very rare, at least for me.


Did you do this in ERG mode? If it felt easy, then your signature is likely underestimated. I don’t usually look very much at my power when doing 30/15 micro-intervals. I usually go by feel, such that I’m at a 10/10 effort by the last couple of intervals for each set. But either way, I’m usually above 85% HRmax for most of the workout…

Most (nearly all) of the Xert workouts are not designed to take you to failure, with the exception of workouts that have the “Breakthrough” tag. Going all out can be good for race prep or for validating your signature, but other than that, they can be unnecessarily difficult & potentially cause unnecessary excess fatigue.

If you’re looking to get a Breakthrough, then you’ll need to hold your 5 min power for at least 5 min. For me, my 5 min power is ~127% FTP, so 5x5 @ 110% wouldn’t be enough for me to generate a BT unless I were to go by feel and push harder than 110%. Side note, this is also why Xert doesn’t recommend many workout intervals by %FTP, since 110% can mean very different things for different athletes.

I did it on “automatic”, which turned out to be ERG. I assumed therefore that Xert wanted me to do the intervals on erg, and so just increased the intensity. I probably should have done it more and earlier.

I understand “how I need to breakthrough”. What I’m trying to understand is: What is Xert telling me I should do? How do I know when it wants me to ride an interval at 10/10, ride the set at 10/10, or Ride the interval or Set at a given power? There is nothing in the workout or player that tells you this.

AUTO mode in Xert EBC supports both ERG controlled intervals and Slope mode intervals when a workout is tagged MIXEDMODE.
The difference is you’ll use gears/cadence to reach a target value while in Slope mode.
As a slope-based interval begins, trainer control passes on to you. This requires monitoring the rainbow gauge target/watt arrows on the EBC app or gauge and power chart targets on the Remote or Session Player. You’ll need to shift gears and/or cadence to hit the intended targets.

The rainbow gauge on the Session Player includes four indicators to help guide you along on intervals and alert you to potential BT events.


  • Target watt arrow (try to match your gear/cadence watts to this when in Slope mode).
  • Cadence Optimizer (suggested rpm range for target watts).
  • Purple band on the rainbow (will expand if a BT event draws near).
  • MPA gauge (will drawdown or fill back in based on strain level and time spent above and below TP).

Notice when you view a workout like A Pain That I’m Used the chart indicates expected results with your current signature applied. Example:

Where the MPA drawdown line meets a target value indicates likely failure points – if you get that far into each set.
This particular workout is rated 4-1/2 diamonds with 140 Difficulty score (Hard, top of scale).
Many users won’t be able to complete all intervals in each set successfully to the very end.
It depends on your current training status and pain capacity. For example, someone at 2 stars TL will have a hard time completing a 4+ diamond workout to full compliance. You don’t need to do that in order to trigger a BT during this workout. What matters is you tried your best and were able to continue pushing through while MPA is drawn down.

If you prefer to try a BT workout designed to be ridden entirely under ERG control when in AUTO mode, try this one.

Notice how MPA drawdown dips below expected failure points. You should fail during those intervals. If not, it means your signature is understated.

If you’re following Xert recommendations, just follow the workout power targets… from the training advisor… it does give power targets… and they are different for each workout depending on intended difficulty, focus, program phase etc… (The choice you have is whether to ride in ERG or not, but follow the target either way).

This assumes your signature is up to date. If you want to know in advance how hard a workout will be (eg to check whether your RPE is in line with that ‘expected’ for the workout) you can look at both difficulty score (higher is harder) and / or look at the workout graph to see how close MPA comes to target power (closer = nearer BT = harder). If a high difficulty workout, or one that brings your near BT feels easy, there’s a good chance your signature is too low

Xert doesn’t ‘recommend’ breakthrough workouts which are the only ones that are all out. You will get a small warning when your signature is ‘stale’, but it’s still up to you to get a BT however you want

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Ok I have had it with this beta level software.

Workout scheduled in the planner. Log in a bit early as my timeline changed - hey thats xerts flexibility right?

No. I can only warmup. I can’t start the workout. I can’t skip the warmup. There is no way to do this. Now I can’t do my session as I won’t have time this afternoon because they didn’t think that anyone might want to just log in an go straight to a workout.

I spent 25 minutes searching for a solution. There is nothing in the wiki. Nothing in the blog. Nothing on the forums.

I have no idea who coded this but I am so angry with them; almost to the state that I hope the company goes bankrupt.

If you schedule a Session it starts at the scheduled time.
You can always use Play Now from the Training page (and elsewhere) to start a workout on demand. You can also clear a selected workout/session from the Training page and pick something else.

See details in my Onboardiing post –

Nope, no way to clear it and start the workout from ebc. Not possible once in the 30 mins pre workout.

Why is there no skip warmup button?

Why has no effort been made to make anything in anyway user friendly?

EBC syncs to whatever you have selected or scheduled on XO (
When you change selection on XO, swipe down on EBC app to resync with XO.
Are you using iOS or Android EBC?

Why is there no skip warmup button?

Agreed, That would be a useful function when riding a session solo.
Sessions were designed to support group workouts so a scheduled Start time supports a warm-up period for those who join the session before it starts.
As it works now the only way to shorten a warm-up is by editing the Start time. For example, schedule a session to start 10 minutes from now as you get ready to workout. However, it’s simpler to use Play Now from the Training page.

So planning workouts ahead of time is only reserved for group workouts? what moron decided that?

I didn’t ask set or decide a fixed time. The engine told me to do this workout. I just did 30/15s, yet it told me to do vo2 and sprints the next day. i tried to schedule some z2 but nope - no workouts available.

I mean this is aside from the eye bleach ui, no consideration of hr, 3s interval lag on every set…

You can pre-select whatever you want on the Planner which defaults to a Start time you normally train on same day of the week. I.e. you plan to do the indicated workout at the time noted.
You can ignore this on the Training page by selecting Play Now whenever you are ready to workout.
Play Now queues that workout for selection on EBC.
The workout doesn’t actually run until you start it on EBC.

I appreciate your persistence, but I did this. It loaded it into ebc with the 30 min warmup with no way out. Reset the whole process 5 times. Cleared it in xertonline. No, only warmup until scheduled time.