In a comprehensive review on training, Midgley and McNaughton’s first sentence state’s “The maximal oxygen uptake (VO2max) has been suggested to be the single most important physiological capacity in determining endurance running performance” (2006). Based on this notion, training for distance runners has become fixated on the concept of VO2max. Training to enhance VO2max is the subject of numerous review articles and popular coaching material. A whole theory of training has evolved based on the idea of training at the speed that corresponds with VO2max, and at certain percentages of VO2max (Daniels, 2005). Given the emphasis on this particular parameter one would assume that it must be very closely tied with performance and fatigue. It’s not.

In the following paper the limitations of VO2max will be discussed. Including the legitimacy of the variable itself, why it arose to such prominence, the efficacy of basing training paces off of it, should we even train to improve it, and how closely it ties to performance.

How the VO2max concept developed:
The ability to measure oxygen consumption first arose in the early 1920’s. It was in 1923, when A.V. Hill and his partner H. Lupton came up with the idea there being an upper limit on oxygen consumption. In an experiment which consisted of Hill running at various speeds around a grass track while measuring VO2, it was found that Hill reached a VO2max of 4.080 L/min at a speed 243m/min (Bassett, 2000). Despite increases in speed, his VO2 did not increase, leading Hill to conclude that there is a maximum limit to oxygen consumption, or in his words:

“In running the oxygen requirement increases continuously as the speed increases attaining enormous values at the highest speeds: the actual oxygen intake, however, reaches a maximum beyond which no effort can drive it… The oxygen intake may attain its maximum and remain constant merely because it cannot go any higher owing to the limitations of the circulatory and respiratory system” (Noakes, 2008, pg. 575).

These findings led to two lasting conclusions. First, that VO2max is limited by the circulatory and respiratory system. The second conclusion was the result of trying to device a laboratory test for determining VO2max, in which thirty years later, Taylor et al. decided that during a graded exercise test, a VO2max was obtained when a plateau occurred in VO2 (Noakes, 2008). However, in Taylor’s original definition, a plateau was not a true plateau but it rather consisted of a VO2 increase of less than 150ml/min from one workload to the next. These findings led to the idea that in order for a true VO2max to be reached, a plateau of the VO2 should occur.

Understanding how the VO2max test came about is important as it impacts the way we currently view and use the parameter. The fact that VO2max was first measured during exercise by one of the pioneers of Exercise Science in the 1920’s goes a long way in explaining the level of importance ascribed to it. Whenever a new parameter is discovered or introduced, a large degree of emphasis is put on that parameter in the research. The initial reaction by many scientists is to ascribe a great deal of significance to the newly discovered parameter, as if it will answer all of the questions that we have. It is almost as if it is human nature to go through this process of discovery and then exaggeration of the importance of the new finding. This can be seen in many instances in a wide degree of scientific fields. In Exercise Science, this may best be demonstrated by the rise of the anaerobic or lactate threshold during the 1970’s, 80’s, and 90’s. With the ability to portably test lactate, research was centered on ways to improve lactate threshold and the various methods to test for it. Coaches also devised ways of using lactate testing as a way of manipulating the training of their athletes. Whenever something is new, it is overemphasized, before it usually settles into its rightful place of importance over time.
Due to the very early development of the VO2max concept, a large amount of early research and study was focused on it, escalating the importance given to the parameter. In addition, theories were developed utilizing the VO2max concept very early on. The problem is that early development of the VO2max concept created a situation where there was enormous amount of data and research surrounding it, in essence creating a concept that is too large to break down. It is almost as if the field of Exercise Science was built upon the VO2max concept.

Recently, the legitimacy of VO2max both as a measurement and the acceptance of VO2max as a practical measurement of cardio-respiratory endurance has been called into question. Their contention is that VO2max is not actually a representative measure of the maximum ability to transport oxygen, but is rather controlled by a central governor. In Tim Noakes’ Central Governor Model (CGM), the CGM predicts that the body regulates exercise to prevent myocardial ischemia during exercise. This is accomplished by limiting the blood flow to the periphery which the brain accomplishes by regulating muscle recruitment (Noakes & Marino, 2009). Therefore, VO2max reflects this regulation of muscles recruitment. In essence, a central governor acts as a regulator for exercise instead of exercise being limited by some parameter.

There are several theoretical arguments for this model. Noakes and other CGM proponents point to the fact that fatigue is seldom catastrophic like would be predicted in traditional models. Instead, the body uses various feedback information and past experiences to modulate power output or in the case of running, pace. The idea of pacing being prevalent in endurance events and the fact that a finishing kick, or endspurt, occurs are given as further evidence to support this model (Noakes, 2003). Interestingly, evidence of alterations in pacing strategy and EMG, which measures muscle activation can be seen from the very beginning of performance, such as that seen when racing in warm versus cool weather, which leads credence to the anticipation model of fatigue (Noakes, 2008).

An increase in muscle activation is also seen during the last segments of races, which should not be able to occur if the muscle is “failing” due to fatigue. Noakes’ hypothesis is that at the end of a race, the body’s feedback says that it is near completion so that is can push slightly more into its capacity (Noakes, 2008). Evidence for this hypothesis can be seen in a study by Tucker et al. that found that when completing a 20-km cycling trial in normoxia versus hyperoxia, the improvement in power output in hyperoxia was proportional to the increase in iEMG that also occurred, which the authors cited as evidence that control of muscle activation was one way in which performance was regulated (2007).

Another interesting point raised in the CGM debate is the effect hypoxia has on Cardiac Output. Exercise in hypoxic conditions show a reduction in peak Cardiac Output, due to both a decrease in HR and SV (Calbet et al., 2003). According to the conventional model Cardiac Output, since it is regulated by muscle oxygen demands, should not be reduced. However in the CGM, Cardiac Output is reduced as a regulatory mechanism and is determined by the work done by the muscles (Noakes, 2004). Thus, a reduction in Cardiac Output in hypoxia is due to a decrease in muscle activation, which when supplementary oxygen is taken, Cardiac Output immediately increases to normal levels (Noakes, 2004). This immediate increase in Cardiac Output demonstrates that there is a regulatory mechanism in control and one has to question why Cardiac Output is reduced at altitude when oxygen demand by the muscles should be higher.

In regards to VO2max and how it is tested, Noakes has pointed out that in most cases the original requirement of seeing a plateau in VO2max during an incremental exercise test does not occur (Noakes, 2008). Demonstrating this lack of plateau, in a study on world class cyclists only 47% reached a plateau, prompting the authors of the study to state that their limitations might not be oxygen dependent (Noakes, 2008). It is amusing that some authors have commented that motivation may be the reason some athletes do not reach a plateau (Shephard, 2009). This could be a valid statement if the subjects were sedentary, however since the above study was with world class cyclists, it seems a bit ludicrous to suggest that motivation during a maximum test would be a problem in such athletes. In addition, in other studies, one by Hawkins et al., there have been individual variations in VO2max levels between the traditional incremental test and a supramaximal test (Noakes, 2008). While in the average of the whole group there were no differences between the tests, the fact that certain individuals showed different VO2max is interesting and shows that the traditional test does not always give the highest VO2.

Combining the fact that a plateau does not occur in many subjects and the fact that some individuals reached higher VO2max values during a supramaximal test than the standard incremental one, the use of the standard incremental VO2max should be called into question. Other studies show that knowing or not knowing when a test or trial will end significantly effects physiological parameters, which lends credence to the aforementioned idea. In a study by Baden et al. they demonstrated that Running Economy significantly changed, along with RPE, during a submaximal run based on whether the group knew they were running 20 minutes or whether they did not know, even if they ended up running 20 minutes (2005). The VO2max test is one in which participants do not have an exact finish distance or time, so it is possible that this degree of uncertainty could affect the physiological parameters measured. The study also points to the importance of feedback and anticipation and that it can affect physiological variables.

One final point on VO2max testing is why variation exists based on exercise testing mode (Basset & Boulay, 2000). A runner tested running versus another modality such as cycling will have different VO2max values. There is great individual variation too, between 0 and 13% in the aforementioned study. If we recognize that regardless of exercise the oxygen cascade from the air through delivery via Cardiac Output are central adaptations and should not be different between the exercise modes, then the change in VO2max must either happen on the muscular level or it is regulated via muscle recruitment. This would explain why elite cyclists reach higher percentages of treadmill VO2max when testing cycling VO2max compared to lower level cyclists (Basset & Boulay, 2000). Lastly, the fact that muscle mass activation seems to be the major reason for variations in VO2max among a whole variety of testing methods, shows that muscle activation may play a significant role in determining VO2max, at least to a certain point (Dalleck et al., 2004).

Considering this new theory of fatigue, and the fact that the requirement used for reaching VO2max does not occur in many subjects, the use of VO2max as a testing parameter is called into question. In addition, if VO2max is regulated, then the question arises if it accurately reflects cardio-respiratory endurance. If we accept this to be true, then using VO2max and percentages of VO2max for training might not give the training response that we think it does.

Efficacy of basing training paces off of VO2max

With the rise of VO2max research, training is based on the parameter in two ways. First, training at the speeds that elicit VO2max has become the magic training intensity which supposedly elicits the most improvements. Secondly, training at percentages of VO2max has become en vogue as a way to quantify training intensity.

In regards to training at VO2max, this arose because of a review of research that showed that the largest improvements in VO2max occurred when training at an intensity that corresponded with the parameter, irregardless of duration of the exercise (Wenger & Bell, 1986). This finding was subsequently used to demonstrate that training at VO2max was the best intensity for improving endurance in all groups of people. There are two problems with this conclusion. First, the studies findings are generalized to all groups, even though, as we will talk about later, VO2max does not improve in well trained individuals. Secondly, VO2max and endurance performance are used almost synonymously, which is not true, as discussed earlier VO2max may not even measure cardio-respiratory endurance and is certainly not the only factor in endurance performance.

Despite these concerns, training at VO2max has risen to prominence. In looking at the research, there are countless studies and reviews that focus on training at this intensity (Midgley et al., 2006). It has gone so far, that maximizing the time spent at VO2max has garnered much attention (Midgley et al., 2006). Researchers have studied the various interval training programs with the sole goal in seeing how much time at VO2max each subject spent during the training, which in itself is interesting because it shows the emphasis on the parameter instead of performance. The thought is that time spent at VO2max is the stimulus needed to improve VO2max. However, this theory has not been substantiated by research. For instance, in a study by Billat et al. after 4 weeks of training using an interval program designed to elicit time at VO2max, VO2max and, more importantly, performance did not improve (1999). In addition, even in untrained people, the original review by Wenger and Bell stated that improvements in VO2max at high intensities were not dependent on the volume of training (1986). Despite these facts, researchers continue to press on with the idea that time spent at VO2max is the key ingredient for improved endurance, even though no research backs up this theory.

Using %Vo2max to quantify intensity is an accepted practice in research and is used in many training programs, such as those prescribed by Jack Daniels and Joe Vigil (Vigil, Daniels, 2005). The problem with this approach is that each individual will have a wide range of adaptation, even if training at the same percentage of VO2max. This occurs due to differences in the individuals physiology. For instance, lactate threshold can occur at wide range of %VO2max, even in trained individuals (Brooks and Fahey, 2004). As an example, if two trained runners both performed at a fixed intensity at 80% VO2max, one can be below lactate threshold and one above. This would substantially impact the energetics of the workout, as can be seen in a study that showed there was a 40-fold range for increases in lactate levels at 70% VO2max among individuals (Vollaard et al., 2009). In a recent study by Scharhag-Rosenberger et al. they tested whether exercising at the same %VO2max resulted in similar metabolic strain. They found large individual variance in the lactate response at the fixed intensity, even if groups were matched for similar VO2max values. This led them to conclude that the use of percent VO2max values for training or research should not be used if the goal is to have similar metabolic strain by the exercisers.

In addition to lactate differences, other factors such as the individuals substrate use, fiber type, and other physiological variables will all vary considerably at a fixed percent of VO2max. This was demonstrated in a recent study by Vollaard et al. (2009). The study showed that while on average improvements were seen in a variety of endurance parameters after six weeks of endurance training, the individuality of the response was widespread with some showing even negative responses to the training, even though the training was at the same 70%VO2max intensity for all subjects (Vollaard et al., 2009). The study showed that there was a wide range of adaptation in maximal and submaximal tests including VO2 parameters, muscle enzyme activity, and metabolite levels. An interesting finding in the study is that low responders for an increased VO2max were not low responders in other parameters. The change in VO2max did not correlate with the change in performance on a time trial, which is a significant finding demonstrating that perhaps more attention should be paid to changing in performance instead of manipulating physiological parameters such as VO2max. One has to question the training recommendations based on training designed at improving parameters such as VO2max, with the assumption being that performance will improve because of it, when studies show that change in VO2max are often not linked with a change in performance. This phenomenon of varied response is not new and can be seen in a wide array of training situations, such as altitude training for example (Chapman et al., 1998).

Knowing the wide variance in adaptation that can occur when training at a fixed percent of VO2max, its use has to be called into question. In fact, the author’s of the study questioned the use of %VO2max as a way to standardize intensity and suggested standardization on parameters that more directly effect power output. These findings combined with those by Scharhag-Rosenberger et al. suggest that the use of %VO2max should be eliminated if the goal is to standardize an intensity. One has to really wonder about training programs that use %VO2 to prescribe training as what adaptations will take place are almost a crapshoot. This does not seem like a scientific way to train, as it is portrayed. In practical terms for trained distance runners, it probably makes more sense to standardize paces in relation to their recent race performances or based on percentages of goal race pace in well trained runners.

Should we train to improve VO2max?

As mentioned previously, studies have shown that training at VO2max elicits the most improvement in VO2max. This has been used as reasoning for training at VO2max because, as previously discussed, VO2max is the traditional measurement for endurance. The logic is that if VO2max is increased, endurance performance increases. This may not necessarily be the case. In addition, the question arises if VO2max actually improves in well trained runners? It doesn’t.

Showing the separation of VO2max and performance, the Vollaard et al. study found that the change in VO2max was not related to the change in time trial performance (2009). Studies demonstrate improved performances without changes in VO2max (Daniels et al. 1978). Also, studies show that VO2max can improve without changes in performance, which is seen in a study by Smith et al. that showed improvements in VO2max by 5.0% without an improvement in performance over either 3,000m or 5,000m (2003). In addition, in looking at long term changes in performance in elite athletes, changes in performance occur without subsequent changes in VO2max.

In highly trained athletes, many studies have shown that VO2max does not change, even with performance improvements. In one of the only studies done on a large group (33) of elite runners, Arrese et al. tracked changes in Vo2max across three years. Performance improved by an average of 1.77% in men, and .69% in women, with VO2max remaining essentially unchanged (~76.56 vs. ~76.42 in men, and ~70.31 vs. ~70.05 in women) (Legaz Arrese et al., 2005). Similarly to the case study by Jones, this points to improved performance in elite runners without changes in VO2max. Furthermore, it has been shown that among homogenous groups, such as well trained runners, VO2max does not correlate well with performance and can not be used to distinguish what runners are faster (Legaz-Arrese et al., 2007).

Further evidence can be seen in two case studies on elite runners. In a study on a female Olympic level runner, Jones showed that while the athlete’s 3,000m time improved by 46 seconds, there VO2max decreased from 72 ml/kg/min down to 66 ml/kg/min (Jones, 1998). Another study by Jones, this one on the current women’s marathon world record holder, found that while VO2max varied some based on the time of testing, it was essentially stable at 70 mL • kg–1 • min–1 from 1992 to 2003 (Jones, 2006). The fact that Radcliffe’s Vo2max was essentially stable despite her training volume and intensity increasing substantially is intriguing. Her training increased from a modest 25-30 miles per week (and her VO2max was already 72 at the time) to 120-160 miles per week. The fact that VO2max did not change despite this massive increase in volume and intensity points to the short time course of changes in VO2max.

The rapid change in VO2max can even be seen in untrained individuals. In a study by Smith and Donnell, they evaluated the changes in VO2max over a 36 week training period (1984). VO2max substantially increased by 13.6%, but all of those gains were seen in the first 24 weeks of the study with no further increases during the final 12 weeks. Similarly in a study by Daniels et al. in untrained subjects VO2max increased during the first 4 weeks of training, but did not increase after that even with a further increase of training, despite continued improvements in performance (1978). Given the evidence that VO2max does not change in elite runners and does not correlate with performance, training focused on improving VO2max does not seem like a logical idea for well trained runners.

Vollaard et al. may have put it best when they came to the conclusion that “Moreover, we demonstrate that VO2max and aerobic performance associate with distinct and separate physiological and biochemical endpoints, suggesting that proposed models for the determinants of endurance performance may need to be revisited (2009, pg. 1483)”. There recognition that aerobic performance and VO2max are not direct equals or even well linked is a step in the right direction and needs to be acknowledged to a much greater degree. Combining these findings with Noakes’ CGM creates a situation where VO2max may not be measuring what we think it is. Adding the facts that using %VO2 to classify training results in a wide range of adaptations and changes in VO2max do not occur in trained athletes, one has to question basing entire training programs on VO2max.

The bottom line question that needs to be asked is why is so much of training focused on a variable that does not change in well trained athletes, barely changes in moderately trained, levels off after a short period of time, and does not even correlate well with performance? Does this sound like a variable that we should be basing all of our training off of?



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    1. Quentin. on December 17, 2009 at 10:04 am

      Excellent, enjoyed reading this. As a cyclist it has always seemed more logical to me to base training on FTP than MAP and your article seems to me to support this view.

    2. Stan on December 17, 2009 at 11:03 pm

      Great article, thanks for sharing this info. Here is why I think the same:

      I got tested for Vo2max when I was about 17 when I was seriously racing triathlons.

      Now I race in the winter (similar sport to xc-skiing) and I am 10 years older. Got tested for Vo2max lately and it incresead from 65 to 68. But when you look at the results, the value jumped to 68 only in the very last minute of the test where I was pushing outside of my limits. It was on 65 for about 5min before that.

      And Vo2max is nothing more but your total capacity divided by your weight, so unless you lose wait it ain't gona improve. And I am basing that on my old coach wisdom as he believed based on seeing lots of results data from various athletes that the maximal capacity is what you pretty much get from God and from there you can't do much about it (assuming of course you are not a couch potato and start running all of a sudden.)

      Also, this findings make Greg Lemonds accusations of Alberto Contador totally invalid as this shows that you cannot say that someone needs to have a certain Vo2max to go at a certain speed.

      What do you think?

    3. stevemagness on December 19, 2009 at 12:54 am

      Quentin- Thanks for checking out the blog. I'd agree, basing training on FTP seems like a more sound approach.

      Thanks for the personal experience.
      I'd agree completely that you cannot say that someone needs to have a certain VO2max to reach a certain speed. As Tim Noakes says, as long as your in the club (of having a moderately high VO2), it doesn't matter how high it is. Meaning, we can't predict whether some guy with a 70 VO2 is better than someone with an 85.

    4. Anonymous on December 19, 2009 at 7:34 pm

      Are comments moderated?

      Please have your highly informative articles proofread by a grammarian before turning them in:

      > while the
      > 3,000m time improved by 46 seconds,
      > VO2max decreased

      (and more)


    5. Anonymous on December 20, 2009 at 4:17 am

      excellent article. Thanks for the infomation. I will use this with my runners I coach.

    6. benrattray on December 22, 2009 at 1:46 am


      Agree completely that there is an over-emphasis on VO2max, although that does not seem to be the case much here (Canberra, Australia).

      You should however be careful with some of your conclusions. For instance, you can see an increase in VO2max in elite athletes through a season, and when they prepare for a major race – e.g.

      Similarly there is evidence that training at vVO2max increases performance more than when you only train at a slower speed – e.g. look up Interval training at 95% and 100% of the velocity at VO2 max: effects on aerobic physiological indexes and running performance

      As well as instances where VO2max is the best predictor of 5km performance – e.g.

      So im just suggesting that even though overall I agree with you, you have written quite a one-sided story that I think could be balanced out.

    7. stevemagness on December 22, 2009 at 2:22 am

      Ben, Thanks for the comments.

      Good article by Billat. I agree that VO2max can potentially change in elites. The majority of studies, both case studies and several year studies looking at VO2max show that it rarely changes in elites. I prefer the year to year studies where there tested at the same time in the competitive year.

      Testing of VO2max from one point to the next is sometimes suspect because you don't know if they initially had an "artificially" low VO2max because they were coming off of break or reduced training or a base period of only mileage,etc.

      I agree that training at vVO2max can improve performance. The point of the article is that it most likely is NOT because of the mechanisms that many claim it to be, mainly an increase in VO2max. For most of those studies, could it possibly be performance increases b/c they are training at a pace that is specific to the race they are training for and therefore increases specific endurance.

      The point of the article is to get away from a training program based solely on VO2max paradigm and shift to a performance based one, which in the end is what matters.

      Agree though that it's one sided. That's why it's not a straight, traditional lit review.

      I guess in the end, I'm not saying VO2max is totally worthless, just that in the training and in the research literature it's importance is overemphasized, largely because of tradition and the fact that it can easily be measured. I see it similar to what happened with lactate. When fatigued happened initially, we saw that it corresponded with lactate increases. WHy? Because we could measure lactate. Years later, we've realized that it doesn't cause fatigue.

      Thanks for the thoughts.

    8. Fat Rat on December 22, 2009 at 11:44 pm

      Hi again Steve,

      It just seems you have a bee in your bonnet about the "science" which I don't quite get. There is good and bad science, just as there are good and bad coaches, and there are good and [mostly] bad messages coming through TV advertising every day in order to sell a product.

      You wrote: For most of those studies, could it possibly be performance increases b/c they are training at a pace that is specific to the race they are training for and therefore increases specific endurance. Well, yes, but why can't that be the same as some physiological measures that science is reporting?

      Most people don't really behave differently. Most (essentially all) will increase their VO2max between an untrained and trained state. The capacity to train different factors that contribute to overall performance may indeed alter between athletes, but the need to meet metabolic requirements within working muscle is fairly standard.

      I have heard Noakes speak numerous times, and been fortunate enough to sit with him and chat about things. He certainly doesnt think that VO2max is unimportant, but he does argue in a provocative way in order to get attention and makes some good points about the overemphasis on such a measure (or any particular isolated physiological measure.

      In the latest post you have made comment about effeciency in terms of mechanical, metabolic and neural. I'm not exactly sure what you mean by this as in order to have an effeciency, two measures have to be linked, but I look forward to the future post. Both neural (e.g. force relative to EMG) and metabolic (e.g. running speed (distance covered) vs O2 cost) are commonly measured.

      I'm curious to read your economy paper, the comparison you make to cycling economy is not really that pertinent since efficiency (measured correctly, not like the Armstrong debacle) is generally related to power output, and both power and cadence are less closely linked to speed (or distance covered) than similar measures in running.

      Look forward to future posts, its interesting, and you are making me think.

    9. stevemagness on December 22, 2009 at 11:59 pm

      Fat Rat-

      I agree. I come off as too harsh on many occasions.

      I'm in the middle of my thesis and just finishing up 100pgs of lit review on the science of distance running, so that's where I think the sources of my frustration comes. I don't think any measure, like VO2max or LT or whatever is completely useless. I sometimes say they're 'useless' to emphasize the point I guess. I just think many are overemphasized or have been assigned too much importance.

      It arises from the large disconnect between scientists and coaches. During my lit review, the vast majority of the journal articles favor a high intensity/VO2max centered/low volume training approach. When, the coaches all prefer the opposite. And as a somewhat accomplished athlete who also has coached some very good individuals, its frustrating seeing this emphasis by the majority of the scientists when it runs so counter to what works in the real world.

      Also, from a coaching perspective, I really think the application of science, at least in the United States, is bad. Coaches have developed training programs based solely on VO2max, Lactate Threshold, and Running Economy. I think that application is a mistake.

      I'll explain the efficiency when I get a chance. It's a complex subject and I want to make sure I have everything straight first.

      Thanks for the comment. In the end that's my goal, make people think. I'm fine with being wrong or off on a subject. I'm just always looking for a better way.

    10. Fat Rat on December 23, 2009 at 12:30 am

      fair call.

      in case you havent seen it – you may get frustrated with some of this VO2, oxygen emphasis, but the overall story is that even in terms of the physiology adaptation, there are more than two ways to skin a cat.

      -Wang et al, 2009 – Similar expression of oxidative genes after interval and continuous exercies MSSE 41(12): 2136

    11. Anonymous on December 24, 2009 at 11:26 pm

      For running, what is the equivalent to cycling's ftp?

    12. NYCbiker on December 28, 2009 at 11:17 pm

      Thanks for a very interesting article.

      While I agree with most of your points, I don't agree that VO2 max has no bearing on performance. (or the gentleman's point about Lemond)

      Lactate threshold is highly trainable, and it is not uncommon to see 30%, 40% or even 60% increases in an untrained athlete’s lactate threshold with training. In the cycling world a popular method of training is to train to increase lactate threshold. This is done by targeting intensity (as measured in watt output) at about 80-90% of LT. As the athletes LT rises, the intensity of training is raised so that the athlete continues to train at 80-90% of LT. This has been shown to increase the lactate threshold, and subsequently performance, considerably. But there is a ceiling and the ceiling is V02 max.

      It is pretty common to see an untrained athlete with an LT around 50% of their VO2 max. With training they can get their LT up to 80% or even 90% of V02 max. But the VO2 max is their personal limiter. One can never get their LT intensity to rise above their V02 max intensity. If two athletes have different VO2 max's and have trained their LT to the same percentage VO2 max, the athlete with the higher VO2 max will be the better performer. So if you can increase your VO2 max and ALSO your LT as a percentage, then you’ll see an increase in endurance performance and not just VO2 max. At least that is what we have seen in bike racing. Can’t comment on running.

      The other thing about cycling is that other than time trials or triathlons, bike racing is not a steady state endurance event; it involves both endurance and surges. We do VO2 max specific training intervals because there are many times in a race when one's ability to sustain efforts at VO2 max determines the winner of race.

    13. Anonymous on December 29, 2009 at 8:10 pm

      I am so sorry to have posted inaccurate info. I used Jack Daniels' name in regard to the VO2 myth – worng, so wrong. It is Dr. Anfrew Bosch.

    14. Anonymous on January 23, 2010 at 6:48 am

      Hi Steve, interesting article. Like many who have posted here, I don't think VO@Q measurements are toatally useless. However, I do take your point that it has become obscenely over emphasized in the literature. I think that this is because it is easily measured and is reproducible. As always, rather than measuring what is important, we ascribe importance to what we measure.


      Specifically, I think that

    15. Daniel Riou on October 14, 2010 at 1:40 am


      I'm from Quebec, and here we have what we call VAM or what you would call MAS (maximal aerobic speed). We find it with a clinical test named: léger-boucher test. It consist of running 2 minutes at each speed: 7km/h, 8km/h, 9km/h,… without rest. If you reach 20km/h, then your maximal aerobic speed is 20km/h. Then, mas is used as you would use VO2Max. If you want to improve your MAS, you do intervals between 95% and 105% of your MAS. It pretty much makes sense because it integrates the running economy into VO2Max.

    16. Luc aka Pieds Nus on December 17, 2010 at 11:36 am

      Hi Steve,

      I'm Luc from Barefoot Ted's forum. I am from Quebec as well and like Daniel wrote almost everyone training seriously is using VAM (in France they call it VMA) and the prescription of our training speeds are % of VAM. As it takes into account running economy (e.g. 2 runners with different VO2max could have the same VAM, the one with the lower VO2max has a better running economy).

      I always thought that Jack Daniels' VDOT was also taking into account the running economy as well in the tables that we're using to determine our VDOT on the basis of races results. Was I wrong?

    17. marty on January 30, 2011 at 6:48 pm

      interesting reading. where you talk about figuring out training paces in relation to recent race performances/% of goal race pace]? does this apply to well-trained runners of all abilities? can this approach be utilised by any well-trained runner, whether an elite or a club runner? how does one calculate? cheers marty

    18. Dave Shaw on December 29, 2011 at 1:00 am

      Great read. I have never put much stock in VO2max and this articulates that idea for better than I ever could. I have always been a follower of FT training as that's where the rubber meets the road so to speak.

    19. Derick Williamson on January 19, 2012 at 12:53 am

      Pleased to have discovered this site. Keep up the questioning and the dialogue.

      One thought to add to this post and several others I've skimmed on the site re: Vo2 max; I think a lot becomes clouded in the outcome of Vo2 max and not what actually goes into Vo2/Vo2 Max. The simple Fick Equation of Vo2=CO*a-vo2 diff. When looking at workout design and the ultimate goal of the workout and subsequent adaptations athletes and coaches rarely think through which variable they are working to improve and if indeed that variable is the actual limiting factor.

      Does enhanced muscle recruitment improve the a-vo2 diff thus the working skeletal muscle can actually use more o2 for work? If so, what is a workout that will achieve this? Is HR or SV a limiter, if so what workouts will result in significant venous return and potentially enhance eccentric ventricular hypertrophy?

      I tend to agree with your attitude toward Vo2 max and it's influence to absolute performance but I do have to throw in, that there are components of Vo2 that often get overlooked but could be beneficial to training design. Of course there are plenty of other variables to consider for performance but as it relates to Vo2/Vo2 max, I think it is beneficial to move away from the max outcome and focus more on what goes into the product.

    20. mamun mizi on November 7, 2012 at 7:04 pm

      Just wish to say your article is as astonishing.
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    21. Anonymous on September 14, 2013 at 2:13 pm

      Thank you for this thought-provoking piece.

      However, for "keep fit" runners such as myself, the goal isn't necessarily to improve race performance, but merely to improve cardiovascular health by means of exercise.

      Is VO2 max a sensible parameter to target to improve one's health? I realise this is not your focus, but I would welcome any pointers anyone can give me on that question.

    22. Katheryne Clark on April 9, 2014 at 10:13 pm

      I would like your thoughts on Anonymous' questions too! 🙂

    23. James Carroll on October 31, 2015 at 2:05 am

      I am a strong supporter of VO2 max as the primary factor. For example, racing sled dogs have extremely high VO2 Max ratings and are ultra-endurance race competitors, covering 1,100 miles over periods in excess of nine days. Have you ever reconsidered researching historical evidence of Australian Aboriginal men that were daily chasing kangaroos or waterbirds barefoot? In south-western NSW about 20,000 years ago, there is evidence (footprints in mud) of Aboriginal men sprinting at 37 kilometres an hour, and still accelerating (barefoot). We of as humans have lost much of this ability. The human calf muscle is the key component, which makes all the difference over distance.

    24. Erma Casias on January 12, 2016 at 10:50 am

      Thanks for writing this good post. I hope you will write more.

    25. Arman Miah on April 7, 2016 at 8:00 pm


    26. […] What’s the value of VO2 testing for setting zones for newbies and elites? (also check Steve Magness blog for a more detailed criticism of zone training and the issues with VO2max) […]

    27. […] a cyclist. There are some very interesting sports science debates ongoing about aerobic capacity, particularly its measurement through VO2 max, and whether this measurement is the correct one for comparing performances. Ross Tucker suggests […]

    28. MUSCLE QUALITY AND “CARDIO” | Exercise Coach on October 3, 2017 at 12:52 pm

      […] reflect no change whatsoever.  How can this be true?  Well, maybe because VO2 max testing is not a reflection of cardiovascular fitness at […]

    29. […] throughout an athlete’s career. A higher V02 max = better health and performance. However, there has been a trend to devalue the absolute benefit of VO2 max for distance runners¹ in favor of a different metric: running […]

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