Holding steady VO2Max

I struggle to hold VO2Max during workouts without going over to anaerobic or falling back to threshhold. For whatever reason, there’s a 20-30 watt range that I can get comfortable above or below, but struggle to hold. Beyond the obvious answer of “practice, practice, practice…”, is there a good way to get more comfortable in this range?

On a related note, if an interval set is supposed to be sets of 1 minute VO2Max intervals but the intervals end up being 20 seconds anaerobic, 20 seconds VO2Max, and 20 seconds threshhold, am I still making the necessary adaptations?

For VO2 intervals I think the most important thing is to try to hang on to that gasping for air sensation. Higher power is what will get you there but what you are really going for are the cardiac adaptations that come from forcing your heart to pump lots of blood very hard.

So I think that should probably be okay as long as you are hitting VO2max (which that gasping sensation is a good indicator of) then you are good to go and probably getting the desired adaptations.

There is a camp of coaches, researchers, and athletes that think the best way to do these intervals is to do a hard start (maybe 20ish seconds of 150% FTP) and then let the power fade as you hold onto that gasping sensation. The hard start is to get you to max O2 uptake quicker and then you hold that regardless of what the power says.


Every power has some anaerobic contributions. For reference your 1 min effort (we are talking about max effort) has roughly 50:50 relation of anaerobic contribution and aerobic (this is simplification as it’s highly individual thing). So to train aerobic side of things you have to “burn” through anaerobic part. 1 min intervals in vo2 max zone are usually too short train aerobic side of things. So you do not spend enough time with given power to create sufficient oxygen deficit. If you shorten the rest a lot then you have more chance for training that vo2 max part. So basically you are working on your anaerobic side not vo2 max. Use longer intervals (at least 2 min long and rip them as hard as you can) or very short rest (like 15-30s).

If you are not accustomed with this type of efforts and new to cycling, do not care about that - everything will work for you for a some time.

There are quite a few papers where the protocol is completely RPE based, and power is monitored. Others like to just look at time in HR zone.


Noting that I’m not new to cycling or VO2Max efforts, today’s workout was Bluebell +1: These are pretty typical for my VO2Max intervals.



I would say do the same but with 3-5 min intervals and it would be a very good vo2 max workout in terms of structure and adaptations. Start hard, close your eyes and feel the waterboarding effect, gasp for air, pray for survival and repeat. In my personal opinion 1 min on 1 min off is not great workout if you really want to push your central adaptations and really increase stroke volume. VO2 max is not power zone but state and you want to maximise time in this state. This maybe helpful (and read whole blog).:

Of course there is empiricalcycling podcast and anthology about vo2 max (like 6h about why and how from physiological perspective) if you really want deep-dive.

But this is my personal opinion and experience. With this approach my 5min power and vo2 max improved significantly in two years so I know it works for me and it’s only thing that validate the approach :slight_smile:

1 Like

I’d ask ‘is this needed for your race/event/goals’? If you go anaerobic but win the race - does it matter?

Giving actual advice - focus on HR vs. watts as someone already mentioned. I would further this to ask - does it get worse further into the workout? If you can do it fine for interval 1-3 and struggle at #4 then just try to add more and more time in #4 before you pop and give up.

Lastly - just pick different workouts that have maybe less time per interval and more intervals, then start ramping it all up

Worth noting that we’re on the TR forum, and I’m using a TR plan. TR plans have served me well so far, so I’m going to stick with what is working.


Barry you need to redefine your understanding of VO2 max (it’s not a wattage or an HR number), then you will be better equipped and able to answer your own question.


So these are 1 minute intervals? I find the spike at the beginning is typically not intended even though as Jarrson says, a hard start is a technique. It’s usually you overshooting the target in anticipation of the ramp up. You might try working on that start as I think you are kind of in no mans land. A smoother start may allow you to hold it longer. If you are saying 1 minute intervals at 120% is difficult then perhaps 120% is too much for you right now. VO2Max doesn’t just start at 120% and 1 minute intervals are actually very short as it relates to VO2 Max work. There are numerous new workouts that start VO2Max at 106% and above, but are doing 5 minute intervals that you might try to see if you can work on increasing the duration of your effort while slowly progressing the intensity from 106% to 120% or wheverever you end up. Snowshoe Fire is the beginning of a progression with duishuk and haw knob that go up to 113%. I’m sure there are others to continue the progression, but those were the ones I saw in my plan.

1 Like

Let me try this again -
Many TR workouts feature intervals requiring 120% of FTP (as measured by the TR ramp test protocol) for periods of 30 seconds to 5 minutes. While I am comfortable holding 100% intervals at a steady pace, and can hold intervals at 140-200% of FTP at a steady pace (obviously shorter duration), I find it difficult to hit and hold 120% without substantial variability in my power.
My question: If my intervals look like the graph included above, am I still getting the desired adaptations, or do I need to work harder on hitting and holding the 120-125% target without as much variance as I currently see?

Is there a specific reason you are spiking at the beginning? I would say you should try and hold as steady as possible and reduce variance if possible. I’m attaching a screenshot of the workout for comparison.

My guess is that you will get adaptations, but not optimal adaptations. You should be focusing on breathing hard and spinning fast and you might need to slightly lower the intensity to start that process.

Its easy to overthink actual power vs target power. And more importantly a TR workout labeled “VO2max” might actually be about repeatability above threshold (106-120% FTP Coggan Classic vo2max zone), and not actually accumulating 10-30 minutes at 95-100% of vo2max (maximum aerobic capacity).

1 Like


120% is not the top. I did a workout today at 127%

I think the key is that you stay in a vo2max state. Hard to explain that without the comparisons to power. However if you are dipping down into threshold, that’s not what you want.

I’ve just done 4x4 at 103% FTP. At 85rpm definitely at threshold level both by breathing and heart rate. Upped the cadence to 110 and whilst HR was still high threshold my breathing was definitely into VO2 max territory. It feels to me that somebody is slamming a valve shut before I’ve got enough air in.

The 1-min intervals in the Bluebell +1 example are not long enough to push vo2max adaptations. The 6x1-min intervals are really about glycolytic repeatability / anaerobic stamina. There is considerable variation in power between people, so they are best done self-paced. A starting target for many will be in the range of 120-150%, for example when I do 1-min repeats my target is 135-145% depending on how many I have recently done.

One source of confusion is that prior to adaptive training, TR labeled most workouts by power zone, not by adaptation goal. And that can be confusing above threshold. In particular because there is so much individual variation above threshold. Its why Coggan Classic zones were updated to Coggan iLevels about 5-6 years ago.

1 Like

Outdoors. Gearing varies, cadence typically 90-100.

If you struggle to purposefully maintain a vo2 max power range it’s prob too high of a target. Vo2 max power range should be able to be held for many minutes with training (up to maybe 10-15). It’s a range of course tho so just tone it down a bit and I’d suggest aiming for longer intervals of lesser intensity. Based on FTP, maybe 110% for 3-6mins. Should be able to stretch that towards 10min or so.

If I was going to do 1min on 1 off I’d prob shoot for 135-150% and I could see later reps of that starting to unravel on the consistency of holding the power. But this shouldn’t be happening at like 1min effort at 105-120%.

I’m not suggesting yours doing it wrong, I am implying it shouldn’t be that hard to purposefully hold that power for a min.

As far as getting fit, yeah doing what you’re doing will still get you fit. I wouldn’t read too much into what studies in a lab said. I think if your throwing it down hard for a min multiple times in a row, you will be breathing hard enough to be training your vo2max (and power). Controlling the effort probably will allow you to perform more reps and therefore have more training time at vo2max. That’s the potential benefit you may be missing out on with the spiky power.
I’m a big fan of 30/30 as well (30s at ~150% ftp then 30s easy x many reps). Maybe give them a shot if you like spiking the high watts for short. Goodluck