Differences in VO2 Max - How big is the gap?

I assume you meant that Garmin doesn’t specifically use your 5-min maximum power to estimate your VO2max. That is correct. I also didn’t mean to say that, and I wasn’t replying to your post. I was commenting in general.

Garmin’s algorithm does allow it to estimate VO2max from sub-maximal efforts, I think. Other people probably know more.

Your 5min max power in w/kg would serve as an excellent proxy for vo2max. Despite these calculators, you’re not going to have an accurate estimate without an actual maximal test. Just give it some thought and you’ll realize why. It’s like the AiFTP.

1 Like

Agree. But I think for many of us, exact VO2max value in itself isn’t very important. Rather, FTP as percentage of estimated VO2max using 5-min max power effort (i.e. fractional utilisation) serves as good indicator whether to focus on threshold or VO2max work for next training block.

Fractional utilisation = FTP / 5-min power x 100

  • below 75%: ceiling (VO2max) is already high, good time to raise the floor (FTP)
  • 75-85%: either do mix or focus on one, whatever is current preference
  • above 85%: FTP is close to limit relative to VO2max, need to raise ceiling before can improve FTP further

This is useful background knowledge if trying coaching yourself and goal is to improve overall fitness. Of course, when goal is racing and peaking for specific dates, then it is better to follow plan that shifts training specificity as target date nears.

3 Likes

Anecdote.

When my VO2 was ~60, my FTP was ~3.8w/k. When my VO2 was ~70, my FTP was ~4.5w/k. I tend to have a low fractional utilization.

In practice this is the difference between a 100k z2 ride averaging ~30kph vs ~34kph.

1 Like

Yeah but the point is, to know either of those numbers, you need a real test. For ex, you actually have to ride as hard as you can for 5min. Or say 20min to estimate ftp, etc.

And to OPs question, the delta between your about 60 test and about 70 test is about 20% in ftp. You obv had a lifestyle/training change to induce the improvement, and let’s assume 70 is your upper limit.
So if 60 was your upper limit (fully trained and at 60), then a person who is fully trained at 70 is in a totally different ballpark. 20% is a massive difference

Between this thread and the “post your CTL” thread I’m kind of wondering why I even race. Or continue training. Doesn’t seem like it will ever matter.

3 Likes

There’s more to racing than numbers. If you want to be a world tour pro, sure, you might want to let that one go, but age group local races can be fun and keep you fit. There’s plenty of ways to be competitive without a huge VO2 max number. At least that’s what I keep telling myself lol!

5 Likes

If you don’t have the power numbers or time to train you have to find another way to make the gains.

There are a few riders locally who can compete and sneak out occasional wins while being objectively less fit/strong than other riders.

If you pick your races well, get a super aero position and get really really good at hiding from the wind and picking your moments you can definitely be competitive against people with a higher FTP.

2 Likes

This is always an interesting thing that I’ve seen everywhere but doesn’t seem to jive with my experience the past several years. For me, the only times my FTP has increased significantly are (1) after a training camp/volume block and (2) after a VO2 block.

Through periods of heavy FTP intervals my FTP doesn’t move. My TTE can almost double (~40min to ~70min) but FTP stays the same (+/- 5 W).

But within a month after completing a VO2 block my FTP will go up 10-15W.

So if I followed this advice and waited till my FTP was over 80-85% of my 5min power then I’d never go to a VO2 block and thus rarely/never see FTP improvements. So I’m always interested in if this is something that people actually have experienced in their own training or if it’s just something that’s often repeated but doesn’t stand up to actual experience.

1 Like

Good question, and to be honest, I have learned it myself from this forum in various topics.
Anyway, now that you asked it, checked with ChatGPT and this is answer it gave (copy and paste):


1. Physiological Basis

  • VO₂max sets the upper aerobic limit:
    VO₂max represents the maximal oxygen uptake and indicates the total aerobic capacity of an athlete.
  • FTP (or lactate threshold) represents sustainable power:
    FTP reflects the ability to sustain a high fraction of VO₂max over time, governed by lactate clearance and muscular endurance.

The fractional utilization metric helps identify whether an athlete is limited by aerobic capacity (VO₂max) or endurance at a given percentage of that capacity (FTP).

Key Sources:

  • Coyle, E. F. (1995). Integration of the physiological factors determining endurance performance ability.

Coyle discusses the roles of VO₂max, lactate threshold, and cycling efficiency in determining performance.


2. Research Supporting FTP as % of VO₂max

  • Seiler, S., & Kjerland, G. Ø. (2006):
    Quantifying training intensity distribution in elite endurance athletes.

Seiler and colleagues note that elite endurance athletes tend to have a fractional utilization of 80–85%, whereas less-trained athletes are closer to 70–75%. This distinction highlights the importance of training interventions to improve either VO₂max or threshold depending on the athlete’s profile.

  • McLaughlin et al. (2010):
    Relationship between VO₂max and endurance performance.

This study emphasizes that fractional utilization is a key predictor of performance, as it represents the percentage of VO₂max at which an athlete can sustain prolonged efforts.


3. Training Recommendations in Practical Literature

  • Training and Racing with a Power Meter (by Hunter Allen and Andrew Coggan):
    • This book extensively covers the relationship between VO₂max, FTP, and performance. It discusses using FTP as a percentage of VO₂max power to guide training focus.
    • It notes that a fractional utilization of 75–85% is common in trained cyclists and can help tailor VO₂max vs. threshold training.
  • The Cyclist’s Training Bible (Joe Friel):
    • Friel highlights the need to balance VO₂max and lactate threshold work, with fractional utilization serving as a guideline for prioritizing training blocks.

I would also doubt whether the FTP/vo2max ratio is that trainable and not simply more down to personal physiology. Just like @mwglow15 , my experience has been that 5min max power and FTP move hand in hand.
September 2023: 5min 430W, FTP 330W, ratio 76.7%
December 2023: 5min 440W, FTP 340W, ratio 77.2%
March 2024: 5min 455W, FTP 350W, ratio 76.9%
September 2024: 5min 473W, FTP 360W, ratio 76.1%
January 2025: 5min ~485W, FTP 370W, ratio 76.2%
I have similar kind of anecdata from my clubmates. I very much doubt I will EVER get even close to a 85% ratio! That would most likely require a lot of muscle loss so that my anaerobic capacity would go down and I would lose a lot of my 5min power, haha. More likely is that I will further increase my 5min power in relation to my FTP since I have now started going to the gym after a few years’ hiatus, with the goal of some hypertrophy → more sprint power and anaerobic capacity.

3 Likes

Research results apply at group level. Individual variability can paint completely different picture, even when including data from number of clubmates – you likely have similar terrain / peak dates / goals / specificity that dictates type of training you do. I am not coach nor physiologist, I don’t know really.

But it certainly correlates with my experience:

  1. when started structured training, ratio was 69% (this datapoint we can skip, knew nothing about pacing, or anything about endurance)
  2. in 2 years, with TR SSBHV plans, moved to 74% (TTE ~40min → fragile FTP)
  3. now, after focusing 3 years on long distance riding, it reached 86% (TTE ~70min → durable FTP) and I really can’t increase it anymore with Z2/SS/Z4-centric training

Two datapoints (2) + (3) only show ratio shifting due training regimen. To actually prove that it works, I need now 3rd datapoint with longer high intensity block shifting ratio lower again. As it happens, I am in middle of reverse periodisation block (3 weeks of anaerobic intervals down, 3 weeks of long VO2max intervals to go). After anaerobic block, AI FTP remained same, even if volume was 1/3 of usual, I actually expected it to go lower.

My point is that I would find it pretty odd for anybody’s FTP to go up and yet 5min power to stay the same or even go down. Never seen that in anybody!
Take W’ or the theoretical “battery” of kJ you can do over FTP. For me it’s stayed pretty constantly around 30-35kJ, as I have been able to do 100-115W over FTP for 5 minutes or 300 seconds. If my 5min power stayed the same at roughly 485W, to achieve even a 80% ratio of FTP/5min I would need to increase my FTP to around 390W. Alright, that is a very large increase! But even barring that, this would mean that my W’ would have actually decreased, as I would only be able to do (485-390)W*300s = 28.5kJ of work over FTP. Why would raising my FTP cause my anaerobic capacity to decrease like that?

My point is that I never see anybody’s W’ actually decrease if they train in a well-rounded way. If they purposefully lost muscle or never trained any anaerobic efforts, sure, but I am not sure anybody here is advocating for that (and I don’t know why such regime would be in any way good for magically increasing FTP). And building up your anaerobic capacity back up is easy, it should increase quite swiftly in 1-2 months of targeted training.

Right, and this is not what research says either.

My understanding of this ratio is that once you reach either edge of it (<75% or >85%, not exact numbers, individual abilities still apply), it becomes harder to move further outside this range in same direction.

On my example: I have reached 86% and now it is hard to increase FTP without improving VO2max first, although I still can increase TTE. I have tried 2 years with very long SS, very long 95-98% FTP, 8-16min 102-105% FTP, over/unders. Or in other words, my training intensity distribution has been tilted for a long time due my preferences and as consequence, I can’t improve further until I work on my weaknesses. Basically, exactly opposite of “train in a well-rounded way” :slight_smile:

EDIT1: or in your case, if you prefer/need short power, have you tried reaching 70%?

EDIT2: there are more nuances going below 75% than I understand (a la improving anaerobic contribution, not only VO2max)

1 Like

It’s interesting that you have managed to move so radically from 74% to 86%. You describe that you have increased your FTP a lot over the years with very long SS, over-unders etc. So basically extended threshold work – threshold being applied pretty broadly here. I have also worked on my threshold quite a bit but I have never found it to have an effect on my FTP :smiley: Perhaps I have not extended TTE quite as long as you have, but I have progressed to 2h TiZ at around 92% FTP (once doing that in one single interval – not fun!) and FTP TiZ to more than 1h, with the longest continuous effort at 60min. But those kind of training blocks have always been followed by blocks with more work on raising my vo2max, as the threshold training has not moved my FTP up in a meaningful way. But after the vo2max block, the FTP has always risen along with the 5min max power. I know I would like threshold work to raise my FTP as targeted vo2max work sucks big time, haha.

I also haven’t tried “reaching 70%” because this isn’t anything I’ve targeted – to my mind, both 5min and ftp are simply good proxies of your aerobic fitness and they generally seem to move hand in hand. Increasing W’ from 34kJ to 37kJ would bring a modeled increase of 10W to my max 5min power, so that is one way, but such anaerobic gains seem to be pretty temporary and thus only good for a race specific block before the season. And there is a limit to how much anaerobic capacity can be increased, anyway – partly genetic, partly also dependent on your muscle mass.

2 Likes

In my case, it is only expected: focusing on long distance rides, 2x/week taking train to other side of country and then cycling back to home in 8-12h with no stops except for getting more water. Rest of training is to support these rides. In a sense, goal is already achieved, I can do it for 3 months in row, without burning out, with recovery week, of course.

But obviously, no cycling goal can be complete without braggable FTP :grin:

Here I am quite mediocre, I’m afraid – compared to volume, my W/kg is average. I see my weaknesses but addressing it would eat into my long distance volume and motivation. Previous years I have tried improve it with SS/Z4 during winter, current year took reverse periodisation approach. I don’t expect to reach to more balanced ratio but hopefully can at least push ceiling little bit to chase FTP again :stuck_out_tongue:

Yeah, certainly, all the research can explain background but in the end you still need focus on your target specificity.

This is my experience as well. FTP training is training at FTP but it doesn’t improve my FTP, just my TTE. Then a VO2 block bumps my 5 min power up and after recovering my FTP jumps up as well but sort of resets my TTE back to the 45-50min range.

This might be different if I had a big jump in my training volume or I significantly shifted my training balance. But even over 2-3 months of SS and FTP training my FTP typically doesn’t move.

Maybe that’s it – you are near your personal fractional utilisation limit like me (not necessarily in same range as posted above) but you need different ratio value as indicator?

Asked this from ChatGPT, it gave quite longish answer, with TL;DR version:


Individual fractional utilization (FTP as a percentage of VO₂max) varies due to a combination of genetics, training history, and physiological adaptations. Genetically, some cyclists naturally have a higher ability to clear lactate and sustain efforts near their VO₂max, while others may struggle despite a strong aerobic capacity. For example, athletes with more slow-twitch muscle fibers tend to have better endurance and a higher fractional utilization, while those with more fast-twitch fibers excel in short bursts but may need more training to improve sustained efforts.


In my case, I assume it is down to good lactate clearance – I very rarely feel the burn with high intensity efforts, limitation is almost always down to muscular fatigue or inability to suck in the oxygen. This qualitative shift happened after 3-4 months of focused Z1/Z2 block while recovering from injury.

How are you testing ftp when you’re all doing these vo2 blocks. If you are or were using ramp test to estimate ftp, it seems pretty obvious that vo2 intervals (which directly train you for ramp test) increase your ramp test result, and consequently your estimated ftp (because it’s a set percentage of the ramp test results). Similarly unsurprising that ftp intervals don’t improve your ramp test much but push out TTE (when you’re already reasonably trained).

Think about it and it’s not very surprising

2 Likes