Riding to Failure

Hi all,

Does going to failure have any negative consequences? For example on VO2 intervals, clearly repeatability is key, however if you fail an interval does that come with a lasting cost? I remember when I did weight training going to failure wasn’t desirable due to the stress on your CNS, however unsure if there is a read across to aerobic exercise.

A corollary is the goal to avoid gasping during VO2 max repeats, what is the driver of that guidance?

Thanks for any input

The goal for VO2 intervals is to barely get through them really.

First third of interval, really hard.
Second third, really hard, unsure If I can get through this…
Last third, oh my god, I’m about to blow up but I just might make it to the end…

Your HR will be way up there. After many repeats of VO2 intervals, it will be nearing HR max, hopefully not exactly reaching there.

If. you start to fail them, by giving up before end or back-pedalling , it might be the power targets are slightly too high. It could also be you just need to grind them out and last to the end. Its a mental game as well as a physical one at this % of FTP for short periods.

As for does it have negative consequences?
For me completing all prescribed VO2 intervals results in a great fitness bump a few weeks down the line so not doing them 100% means less of a bump.
Also for me, if I give up in them I tend to develop a habit of giving up too early in rides and races. The mental training aspect of cycling can’t be underestimated and is so important for confidence.


@Benrlelliott my opinion is that if you are going to the point where you just can’t turn the pedals during your VO2 intervals, it’s probably too much. By too much I mean the recovery required from that type of effort starts to be more than the benefit you get from it. Eventually it starts to weigh on your motivation.

For me, the goal is to achieve gasping! Based on watching the oxygen going into & coming out of my body during this type of effort…I really only get to a plateau of oxygen consumption when I’m gasping for air. It almost feels like I’m suffocating or drowning.

But it’s not so bad that I can’t turn the cranks over like the end of a ramp test.

Don’t know if this provides any useful info for you or not.

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The goal of VO2 max workouts is a physiological response from spending extended periods of time at maximal oxygen uptake. If you aren’t breathing hard, you aren’t doing it right. The power doesn’t really matter, it just needs to be high enough and for long enough to get your heart rate way up and you breathing hard. I guess the ideal would be the lowest power required to elicit the physical response that you can repeat across the intervals that maximizes time at maximal O2 uptake. Very helpful!

As someone not anaerobically inclined, I prefer the 30s/15s or 30s/30s intervals as they don’t leave me feeling completely destroyed at the end.

For me the other benefit of VO2 max workouts, especially the longer intervals, is mental. They are really hard and you can probably hang on longer than you think. My ability to really push myself and dig deep is improved after build phases and the VO2 work in the SSBII LV phase.

I require additional recovery time (and feel more beat up) from VO2 workouts compared to threshold / over/under / and sweet spot that even have a much higher TSS load, though you might be the complete opposite. That might be something to consider with your schedule and expectations for how you would feel after a VO2 session.


I think this is the question. How much does stuffing yourself into that last interval help or hinder recovery or adaptation? If you get to 50% through an interval and you’re doubting completing it (assuming you’re familiar with VO2 intervals) is the stimulus of 30-90 more seconds worth risking grinding to a hault in a heap? Is there even a “cost” to blowing up? In which case as long as you’re doing the time at roughly prescribed watts, blowing up on the last interval, or having to take watts slightly down in the 2nd half of a workout isn’t an issue.

Having no issues doing my intervals, just curious.

if you aren’t gasping I think the argument that you aren’t at VO2Max would be legit. These should be horrible and DEFINITELY gasping for air.

Go to failure!


Haha - then there are some mixed messages in the workout text, or more likely smashing intervals isn’t good for reading my comprehension. Potentially just thinking less is the answer here

Edit: found the text in Bashful "…these aren’t maximal efforts to failure but repeats that push you closer and closer to your highest oxygen uptake where you simply couldn’t process more air. And that’s not the point where you’re gasping, but the point where your breathing is topped out at a level that’s high bu manageable. "

Great question.

Going to true failure may mean you’ll have preemptively scrapped the subsequent workout(s). No good, because lack of consistency erases potential gains from really hard workouts that you previously completed.

Endurance training at VO2max is riding that fine line where you know your body can barely handle it but your mind is screaming at you to quit. Knowing where that line is takes experience.

Back off from that line too much and you just don’t get gains, or your gains slow way down.


When I’m doing VO2, I find more often than not, I experience the exact opposite. My legs are filling up, HR is rising to a worryingly high number(s) and yet my mind is saying ‘Come on! One more minute. You can do one more minute!’

As Coach Chad says in some of the workout texts, the gains come when you invest and accept the fact that the stress you’re experiencing during the current interval will only serve to make the next interval even more productive.