Anaerobic Workout Failure - Threshold Success

I’m currently on General Build - Low Volume after an increase of 7% in FTP to 255.

I’m finding I’m failing or having to dial down the Anaerobic workouts to get through but I can handle the Threshold workouts without failure or dialing back the percentage. I substitute the weekend workouts for a Saturday group ride and Sunday hills ride.

My goals for the next few months are a (B event) 136km - 1,500m road ride and a (A event) 125km - 3,000m MTB ride.

I will be finishing General Build - Low Volume before the road ride and moving on to the Century - Low Volume to work towards the MTB ride (well, that’s the plan).

Should I be focusing more on Anaerobic workouts to build the required VO2, concentrate more on the Threshold workouts or just keep doing what I’m doing and the Anaerobic will build?

Any thoughts are appreciated.

Hey Stuart!

It is completely normal to be stronger at one type of interval relative to another. Don’t sweat it too much; your anaerobic capacity will increase the more you work on it. For now, I’d recommend dialing down the intensity 3-5% until you find a level that feels hard but managable. Then apply that reduction to all anaerobic/ VO2 workouts. Then, as you progress, you should hopefully be able to inch your way closer to 100% intensity :+1:


Thanks Bryce, I’ll give that a go and dial down from the start and see if I can hold on :crossed_fingers::+1:

1 Like

how is this working out? i am having the same issue. VO2/Anaerobic are killing me but I am able to complete all my tough threshold and SS workouts.

I was having the same issues. Dropping my VO2max stuff to 115% worked for me

1 Like

I start with a reduction of 5% for the workout and then decrease by another 5% if I’m struggling towards the end. The more you do the less of a reduction is required.
I heard Coach Chad say that he needs to work up to these types of workouts if he hasn’t done them for a while, so I figure it’s fairly normal.

1 Like

Training VO2max can be done with different intervall types where you change either length of work or rest between intervalls and the effect of training kicks in after 40-45sec. Then you want to reach a total time in zone for about 15 minutes / session. One intervall type is not considered to be much better than any other… more than event specifics of course…

To enable the VO2max intervalls you might be in need of increasing your power output at the VO2max level or extending the time at the power output in order trigger wanted effect.

You can take different approacheson this, you can look at the different VO2max excercises and try out what type of VO2max training is working best for your, remember, time in zone… could be shorter 3-5 min intervalls or 4-8 min intervalls… this differs in TRs specific race plans…

Or you can target your anaerobic system, looking for anaerobic sessions that have higher peaks and some more rest, targeting your capability to increase power output or anaerobic sessions with a bit lower but more repetable power output.

Personally, I use WKO4 for analytical needs to specificially tailor my intervall intensities and do custom made workouts in TrainerRoad…


How did this work out for you with these intervals? I’m finding it impossible to handle some of the General Build workouts in the final weeks right now but I can smash the steady state, sweet spot and threshold efforts without any issue. Feeling really lost and disappointed with myself after each of them and it is terribly demotivating.

Think it has to do FTP increases. As far as I understand it, you can only bring your FTP up that close to your VO2max. After that, you have to bring your VO2max up, but this might be harder and more genetically restricted than FTP improvement.

If a VO2max workout is set to be at 120% FTP, but in reality your FTP has moved up closer to your VO2max, 120% might now actually be over your VO2max, and feel impossible.

Recently I’ve had a lot of success by dropping the intensity on the VO2max intervals. I was feeling similar to you, frustrated and disappointed with my performance on these sorts of intervals with a few failed VO2max workouts. But during one of the podcasts Coach Chad talked about it being acceptable/required for some people to back off on these from the beginning, it is more about getting your breathing rate up instead of hitting an exact power number. So I did some reading into it and found several sources saying the same thing. So I started backing off on the intensity a bit and have been completing these workouts at a lower intensity ( obviously while still breathing really hard) and my FTP and 10-30min power have all increased over the last couple of months.

I determined that I have to back off the 3min intrrvals at 120% of FTP by 6% (so effectively 114%), however I can do intervals at 112% for 4min and anaerobic workouts with 120% for 70sec and short breaks without having to back off at all. So try the various lengths for VO2max work and find an intensity that works for you. Just make sure you’re going hard enough to get up to at least 90% of your max heart rate and you should see power improvements over time.

1 Like

This is so encouraging to hear as I was seriously feeling like it was just outside the realm of my possibilities to complete these sessions. The breathing thing is really interesting in particular. When I’m breathing for VO2 max intervals, it’s not just the heaviness of the breathing but the rhythm that changes. I’m generally panting to keep up with the workload rather than using heavy breaths, even if I try to slow the rhythm it doesn’t work.

The session that crushed me was Ansel Adams. It felt like I wasn’t recovering at all between those shorter 50s intervals, and then the 2 min break between sets also wasn’t enough. HR flew through the roof in the second set and I blew up half way through the third. Going to try nudging the sessions down in the future because I really am noticing this is a major weakness of mine.

The breathing is the worst part of Vo2Max workouts for me! I often remind myself that “if you’re not gasping for breathe, you aren’t working vo2max”. It gives me a little solace knowing that I’m getting better by panting through this pain and struggle.

One interesting new metric is the 95% vo2max that is found in WKO4. It shows how you aren’t reaping the benefits of intervals if you aren’t going hard enough. So I fully agree that lowering the % is feasible, there are also other well respected coaches that don’t even give wattage targets to their athletes (I’m not one of them but I find this interesting) but rather say: go out and vo2max. After a while, you know what that means.

The interesting thing is that it shows you how much of the good stuff you’re getting.

Here’s a 3m interval I did. It looks pretty good:

Here’s the analysis showing that I really only get 95% of the WKO4 metric, which Tim Cusick says is the good stuff that you really want to elicit adaptation:

(see percentages in bottom right of screen: Time above 95% = 2m7s)

So, I think circling back, make sure you’re going hard enough, and maybe even reduce the time sometimes as opposed to the intensity.

Someone else mentioned this above, change up the types of intervals. I’d look and see from 3-8m where you are the weakest, and look at race/event demands if you are doing any, and pick some new durations from there. Don’t just do the same thing over and over and over again.

Good luck!!

Well, what’s interesting is that 2-3min intervals at lower FTP% (with equal rest to interval duration) are doable for me. It’s the shorter ones in quick succession like Ansel Adams that I’m finding particularly hard. I cannot control my breathing with those and just explode.

When I tried the workout yesterday, it felt like I hit the end of a ramp test by the middle of it. I’m guessing that means I need to bring that intensity down from 130% to 125% or as low as 120% to complete the whole workout without blowing up. Then it’s just a matter of building on that to improve it. Like I said, this seems to be my major weakness, as I had similar blow ups with all my races this year.

ah, those are anaerobic, different beast than vo2max!

those will HURT, no matter how you spin it!

1 Like

I think the legs can do the anaerobic work. My issue was my heart being in overdrive and not being able to keep going. Perhaps I’m holding too much fatigue? Or I’m just not used to that kind of work? Or maybe that motor just isn’t up to snuff yet and I gotta do some better training to build it up. Like I said, I’m feeling lost with it since the steady state stuff isn’t an issue.

hard to tell without seeing everything you’ve been doing. if you’re on training peaks I’d be happy to take a look. can link up here.

With anerobic workouts with such small recoveries it’s more about developing that repeatability and not just the max power side of things. I find that there are two things I have to develop to get repeatability 1) a strong aerobic engine which helps you recover quickly during those short recovery intervals (if you’re easily completing your SS and threshold intervals this is probably in a decent state). 2) the mental fortitude/awareness to focus on just the interval you’re in and knowing that you can eek out one more interval (or the final 10sec), and you continue eeking them out until your done. To me this is harder to learn because we focus so much on the physical preperetion and often forget how much is affected by our mind.

One way to learn it is selecting progressive workouts, maybe start with something similar to Ansel Adams -3, which progresses from easier to harder intervals so you can notch some small victories before moving on to the next harder levels (and harder workouts in subsequent weeks). Also mentally acknowledge those small victories, I will even verbally congratulate myself after really hard sets that I’ve completed well. I can then remind myself later that I completed those intervals, which helps to break mental blocks on types of workouts that I dread.


Focus was definitely the biggest factor! Retried the workout I failed last week again this week and finished it without reducing the power intensity at all. There were some other factors involved here too (reduced cadence from 105 to 100 for the intervals, rode in the evening and had coffee–rode first thing in the morning without coffee last week–for starters), but really, stress at work and having that nagging on my mind made it impossible to focus last week when I failed Ansel Adams. I’m feeling a lot better about myself this week now that I was able to prove to myself I could complete this sucker.

1 Like