Next Article in Journal
Quantifying Accelerations and Decelerations in Elite Women Soccer Players during Regular In-Season Training as an Index of Training Load
Previous Article in Journal
Muscular Strength, Power, and Endurance Adaptations after Two Different University Fitness Classes
Previous Article in Special Issue
Optimization of the Critical Speed Concept for Tactical Professionals: A Brief Review
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:

Utility of Verification Testing to Confirm Attainment of Maximal Oxygen Uptake in Unhealthy Participants: A Perspective Review

Department of Kinesiology, California State University, San Marcos, CA 92096, USA
Author to whom correspondence should be addressed.
Sports 2021, 9(8), 108;
Submission received: 1 June 2021 / Revised: 26 July 2021 / Accepted: 27 July 2021 / Published: 30 July 2021


Maximal oxygen uptake (VO2max) is strongly associated with endurance performance as well as health risk. Despite the fact that VO2max has been measured in exercise physiology for over a century, robust procedures to ensure that VO2max is attained at the end of graded exercise testing (GXT) do not exist. This shortcoming led to development of an additional bout referred to as a verification test (VER) completed after incremental exercise or on the following day. Workloads used during VER can be either submaximal or supramaximal depending on the population tested. Identifying a true VO2max value in unhealthy individuals at risk for or having chronic disease seems to be more paramount than in healthy and active persons, who face much lower risk of premature morbidity and mortality. This review summarized existing findings from 19 studies including 783 individuals regarding efficacy of VER in unhealthy individuals to determine its efficacy and feasibility in eliciting a ‘true’ VO2max in this sample. Results demonstrated that VER is a safe and suitable approach to confirm attainment of VO2max in unhealthy adults and children, as in most studies VER-derived VO2max is similar of that obtained in GXT. However, many individuals reveal higher VO2max in response to VER and protocols used across studies vary, which merits additional work identifying if an optimal VER protocol exists to elicit ‘true’ VO2max in this particular population.

1. Introduction

Maximal oxygen uptake (VO2max) as determined by the Fick Equation represents the maximal ability of the cardiovascular system to transport oxygen and the capacity of the periphery to extract oxygen to support aerobic metabolism. It is apparent that VO2max is related to endurance performance and, more importantly, premature mortality [1]. Because of this link between VO2max and health status, the American College of Sports Medicine [2] recommends 150 min/week of moderate intensity continuous exercise or 75 min/week of vigorous exercise to enhance fitness and improve overall health status, although attainment of this guideline in U. S. adults is relatively low [3].
Despite the fact that VO2max has been measured in laboratory and clinical settings for a century, there is no standardized exercise testing protocol to assess it as the specific work rate increment, stage duration, and gas exchange sampling interval vary across studies. In addition, there is no robust approach to ensure that VO2max is attained at the end of incremental exercise which is problematic when this value is used to prescribe exercise, assess training responsiveness, or describe health status. In turn, relying on an imprecise estimate of VO2max can have negative effects upon the accuracy of these applications which can change the course of decision making made by practitioners or scientists regarding client health. Various primary (oxygen plateau) and secondary criteria (maximal values of heart rate, respiratory exchange ratio, rating of perceived exertion, and blood lactate concentration) are widely used in this capacity, yet each has its limitations (for additional information on this, please consult Schaun et al. [4]) that may make them ineffective in ensuring that VO2max is actually attained by each participant.
Implementation of a second exercise test completed after the incremental test was first identified by Thoden et al. [5] in active adults who required an ‘exhaustive test’ to be performed after the incremental protocol. Later work [6,7] showed that completion of this subsequent higher intensity bout (called the verification test (VER)), performed a few minutes or up to 1 week after the incremental exercise bout, led to similar mean estimates of VO2max, thus confirming a plateau in oxygen uptake and, in turn, attainment of VO2max. For example, in 16 distance runners, data [8] showed that 26 of 32 VO2max tests performed on a treadmill reveal similar (≤2% different) estimates of VO2max between ramp and subsequent verification testing. In seven healthy men, Rossiter et al. [9] demonstrated that VER at 95 or 105%of peak power output (PPO) performed 5 min after ramp exercise elicits similar values of VO2max, leading these authors to recommend either protocol as a suitable way to confirm VO2max attainment. Overall, these data show that VER is a robust procedure to confirm attainment of VO2max in healthy active adults.
Despite these data, a valid concern of VER is that its supramaximal effort would be inappropriate for those who are inactive or at risk for chronic disease who lack the exercise capacity due to aging, presence of comorbidities, or desire to sustain such demanding efforts long enough to allow VO2 to attain a maximal value. However, results from inactive adults [10], older adults [11], and those with obesity [12,13,14] demonstrate that it is well-tolerated and feasible in these populations and leads to similar estimates of VO2max as the ramp test. In addition, data show its efficacy to confirm attainment of VO2max in adults with metabolic syndrome [15] as well as heart failure [16]. Recent data also show that implementing VER reveals more precise determinants of increases in VO2max in response to high intensity interval training in adults with metabolic syndrome compared to graded exercise testing [17]. So, similar to healthy adults, use of VER seems warranted to confirm attainment of ‘true’ VO2max in persons with chronic disease.
A recent systematic review [18] summarized data concerning efficacy of VER in healthy participants and concluded that this is a robust approach to confirm the value acquired from incremental exercise. However, having a more accurate estimate of ‘true’ VO2max in this active population may not be that important as their cardiorespiratory fitness is superior, leading to enhanced health status versus less fit populations. In response to exercise training, an increase in VO2max as low as 1.5 mL/kg/min has been identified as being clinically significant in persons with chronic disease [19]. Thus, in persons having low VO2max and, in turn, diminished health status, any small inaccuracies in VO2max assessment may elicit different responses to training and/or inaccurate diagnoses that may modify choice of various treatment options implemented to improve individual health status. In addition, VO2max is frequently measured as a primary outcome in exercise training studies due to its strong relationship with health status [1]. Moreno-Cabanas et al. [17] concluded that ramp testing misrepresents the training-induced change in VO2max in a majority of individuals with metabolic syndrome, and they emphasized the necessity of VER to better represent the VO2max response to training. However, to our knowledge, no review article has summarized efficacy of VER to confirm VO2max incidence in unhealthy participants. Some studies show that VER leads to similar estimates of VO2max versus graded exercise testing, whereas others show significantly higher VO2max when VER is performed. These equivocal findings may cloud judgment as to whether this additional test should be performed to elicit a ‘true’ VO2max and merit development of a review article to provide a thorough overview of feasibility of VER in clinical populations.
This review summarized findings regarding efficacy of VER to confirm attainment of VO2max in unhealthy and/or inactive participants which, to our knowledge, has not been done. The main questions answered by this review include: (1) is verification testing able to confirm attainment of VO2max in this sample, (2) is it safe and well-tolerated, and (3) is there an optimal intensity or structure of VER to employ to confirm attainment of VO2max in this particular sample? Results from Murias et al. [20] obtained in young and older men concluded that VER is unnecessary to confirm VO2max attainment as mean VO2max values from this test and the preceding ramp test were not significantly different. Recent work from this laboratory [21] also revealed that VER using supramaximal workloads significantly underestimated VO2max, so these authors did not recommend these intensities for VER testing. Nevertheless, these results were acquired in active adults that do not apply to individuals with lower cardiorespiratory fitness. Moreover, no individual results were presented which is important since attaining a ‘true’ VO2max is an individual phenomenon. Recent work in adults with cancer [22], hypertension [23], and obesity [13] reveal that a sizable amount of individuals exhibit an underestimation in ramp-derived VO2max and a higher VO2max value when supramaximal VER is performed, which supports its efficacy in inactive individuals. However, across all studies, the participant population, testing protocol used, and criteria employed to confirm VO2max incidence vary, which does not allow identification of a standard VER protocol in clinical populations. Overall, detecting a ‘true’ VO2max is paramount, as this value can be used to prescribe personalized exercise training, assess efficacy of exercise training, and classify health risks.

2. Materials and Methods

2.1. Search Strategy

We conducted a literature search from February to April 2021 using databases including PubMed, Google Scholar, and SPORTDiscus. The key words used were ‘maximal oxygen uptake,’ ‘VO2max,’ ‘maximal oxygen consumption,’ AND ‘verification testing,’ and ‘supramaximal.’ Additional articles were also identified by using the references lists of selected articles. Inclusion criteria were studies written in English using incremental exercise testing leading to VO2max followed by verification testing to confirm attainment of VO2max at submaximal up to supramaximal intensities. In addition, studies using participants who have or are at risk for chronic disease were included, which encompassed the following populations: inactive adults or children; adults with obesity; older adults >50 years; and adults or children with underlying disease including cancer, diabetes, cardiovascular disease, etc. These criteria were chosen as a recent review paper extensively summarized the efficacy of verification testing in healthy adults [18]. Studies were excluded if submaximal protocols were used to assess VO2max, as well as those not acquiring gas exchange data.

2.2. Outcomes Identified

From each article, we extracted the following information: The traits of the participants including age, health status, physical activity status, and body mass index, which was calculated from height and mass if not presented. In addition, we denoted the exercise modality completed, as well as the specific traits of both the incremental and verification test as well as the recovery duration between these tests. As far as the physiological outcomes, we identified the relative VO2max from each protocol, as well as HRmax and test duration of the incremental and verification test.

2.3. Data Analysis

Results are presented as mean ± SD where appropriate.

3. Results

3.1. Summary of Studies

Table 1 presents a summary of the 19 studies included in this review, consisting of 783 adult men and women and children. The populations included in these studies were children or older adults (n = 2) who are inactive (n = 2), overweight or obese (n = 5), had cancer (n = 1), congestive heart failure (n = 1), metabolic syndrome (n = 1), hypertension (n = 2), cystic fibrosis (n = 3), spina bifida (n = 1), or had spinal cord injury (n = 2). Across participants, age ranged from preadolescent up to adults over 60 years of age. Seven studies contained participants who were inactive, and five studies had participants who were recreationally active. Eleven studies included participants with BMI values greater than 24.9 kg/m2, whereas seven studies included participants with BMI below this value.

3.2. Methods Used to Assess VO2max during Incremental and Verification Testing

Table 2 denotes the methods used to assess VO2max from graded exercise testing and the subsequent verification test. Fourteen studies utilized primary (VO2 plateau) and secondary criteria (RERmax, HRmax, RPE, and/or blood lactate concentration) to verify attainment of VO2max from GXT, although five studies did not report that any VO2max criteria were used. Cycling was the modality used in 14 of 19 studies, with 1 study employing arm ergometry [23] and 4 studies using treadmill exercise in overweight to obese adults [12], adults with hypertension [22], athletes with spinal cord injury [24], and children with spina bifida [25]. The most widely used protocol to assess VO2max during GXT was a traditional ramp test (n = 10 studies), although in nine studies, a step incremental test was used. Studies were characterized by various intervals between protocols, with durations as brief as four minutes to as long as a few hours between tests. Two studies required VER to be performed 24–48 h after completion of GXT.
As far as the intensity of VER, 2 studies used a submaximal protocol [16,26], 15 studies used supramaximal work rates ranging from 105–115% PPO or above maximal TM velocity, and 3 studies [12,26,27] used workloads equivalent to PPO. Eight studies included specific criteria to identify differences in VO2max between protocols which were developed through reliability testing or predicted changes in VO2 for the change in work rate.

3.3. Differences in VO2max between Ramp and Verification Testing

Table 3 denotes VO2max values measured in response to GXT and VER for the studies included in this review. Results from 13 of 19 studies [5,9,10,11,12,13,23,24,25,28,29,30,33] revealed no significant difference in mean VO2max between protocols, although in 7 of these studies [9,10,12,13,25,28,29], individual participants revealed meaningfully higher VO2max (≥3% higher) with VER compared to GXT. Nevertheless, in six studies [14,22,26,27,31,32] the VER-derived VO2max was significantly higher than GXT, with participants’ VO2max ranging from 19–40 mL/kg/min. In one study in cancer patients [21], VER-derived VO2max was significantly lower than from GXT.

3.4. Differences in HRmax between Ramp and Verification Testing

HRmax values from GXT and VER are demonstrated in Table 3. Similar to VO2max, the majority of studies exhibit no differences in maximal HR between protocols. Results from one study in obese adults [12] revealed a higher HRmax in response to VER, although another study [9] showed lower HRmax with VER versus GXT.

3.5. Exercise Duration of Verification Testing

Table 3 shows durations of VER reported in the studies. The shortest duration was equal to 1.5 min [13], with this VER protocol lasting up to 7 min in obese adults performing this bout at 80% PPO [26]. Twelve of nineteen studies were characterized with VER duration less than 3 min [9,12,13,14,15,21,23,26,27,28,29,32], with five studies having duration equal to or less than 2 min [12,13,15,23,28].

4. Discussion

Despite the widespread testing and application of VO2max in the fitness, clinical, and research setting, there is no universal approach to confirm its attainment from graded exercise testing. Verification testing is another widely adopted method to perform this function, yet it has been criticized for requiring an additional intense effort that may be inappropriate in those who are not active or healthy. A prior review by Poole and Jones [34] emphasized the widespread implementation of verification testing to identify a ‘true’ VO2max rather than ‘VO2peak’ in healthy active adults. In contrast, recent work [19] in active young and older men concluded that verification testing is unnecessary due to lack of differences in mean VO2max between the incremental and verification-derived value. The current review adds to this dogma by summarizing existing results from a large population of unhealthy adults and children completing verification testing following a GXT. Obtaining the most accurate VO2max value in this population is vital as it may lead to misrepresentations in their health status or responsiveness to training, which may in turn lead to inappropriate courses of treatment. Results reveal that most studies show no differences in aggregate VO2max between protocols. However, six studies show that VER elicits significantly higher estimates of VO2max, which supports its use when utmost accuracy is required in determining a ‘true’ VO2max on that day of testing.
Identifying differences in VO2max between GXT and VER requires that scientists are aware of the magnitude of error in VO2max estimation for both protocols. The error inherent in repeated VO2max testing ranges from 2–9% [7,14,28,35], with the error in acquiring gas exchange data from a metabolic cart being small (40 mL/min for the Parvo Medics system). This suggests that the remainder of the error is biological and likely related to participants’ ability and motivation to tolerate near maximal exercise. We recommend that scientists perform repeated testing to develop typical error values for their lab and use these values when comparing individual VO2max values between protocols rather than only comparing aggregate values. This approach, albeit time intensive, is preferred since relying on other laboratories’ criterion values is inappropriate due to differences in exercise protocol, equipment, patient population, pre-test dietary and physical activity restrictions, and time averaging intervals, which likely induce small changes in oxygen uptake.
A primary criticism of supramaximal VER testing is that this effort is too intense for inactive, unhealthy, or deconditioned adults to tolerate, resulting in a very brief duration of exercise and greater potential to not attain VO2max due to slow O2 kinetics. However, data from multiple studies [12,15,28,29] using supramaximal VER with exercise duration <2 min exhibit no differences in VO2max between protocols, similar to studies [9,10,29,30] in which VER duration lasted between 2–4 min. A recent study in hypertensive adults [22] used a multi-stage verification protocol eventually requiring a supramaximal workload. Results showed a significant underestimation of mean and individual VO2max values in response to GXT compared to VER. In nine obese adults with VO2max equal to 35 mL/kg/min [26], VER at 105% PPO elicited significantly lower exercise duration (167 s) compared to VER at 80% PPO (418 s), although there was no difference in VO2max between tests. However, VER performed at 80 (+0.16 L/min, 5% higher) and 90% PPO led to a higher VO2max value (+0.24 L/min, 7% higher) versus GXT, although this latter result was a trend (p = 0.06). Bhammar et al. [29] reported that a minimum exercise duration to attain a plateau in VO2 in response to VER in patients with hypertension was 80 s. These results seem to indicate that the appropriate or minimum duration required to allow attainment of ‘true’ VO2max using VER in unhealthy adults and children is similar to that recommended for healthy and active individuals. Thus, it is possible that submaximal intensities or multi-stage protocols may optimize VO2max values compared to GXT, although additional work in larger samples is needed to confirm this result.
Our review corroborates results from healthy, fit adults [17,36] showing no difference in HRmax between GXT and VER. However, a subset of data presented in this study [36] from participants with average cardiorespiratory fitness, exhibited significantly lower HRmax (−3 b/min) in response to VER compared to GXT. This is likely a result of the stepwise protocol used in this study that is characterized by a work rate less than PPO eliciting VO2max combined with a relatively long exercise duration (~20 min) versus the traditional 8–12 min ramp protocol. In contrast, obese adults performing VER at 100% PPO expressed significantly higher HRmax (+3 b/min) versus GXT [12], which may be attributed to their unfamiliarity with vigorous exercise during the initial incremental bout. To identify a ‘true’ VO2max, Midgley and Carroll [37] denoted a difference in HRmax < 4 b/min between GXT and VER. This value encompasses the magnitude of differences in HRmax described in the above studies, so it is likely that these discrepancies in HRmax between protocols are not clinically meaningful.
Considerations as to the exact characteristics of the recovery interval between GXT and VER include the intensity of the verification test, duration of GXT, cardiorespiratory fitness of participants, as well as a potential need to reduce the overall time of the session. Our review (Table 2) shows durations as brief as 2–5 min between protocols [24,25,27,30,31], 5–15 min [13,14,15,22,24,28,32,33], to as long as several days between protocols [10,27]. A recent systematic review [17] concluded that there was no effect of recovery interval on the difference in VO2max between protocols, which would suggest that any duration is appropriate. It is also apparent that some studies require an active recovery between protocols [13,15,23,31], whereas a passive recovery is completed in other investigations [11,14,22,25,29,32]. We recommend that scientists perform preliminary testing to identify an optimal recovery protocol for their specific population, and if this is implausible, then we recommend that they duplicate previously used procedures for that population.
Verification testing is only appropriate to identify ‘true’ VO2max if it is safe and well-tolerated by the participant completing exercise testing. This factor is especially critical in persons unfamiliar with vigorous exercise who may face enhanced risk of complications during vigorous exercise. In male and female survivors of cancer, Schneider et al. [21] reported no adverse events in their participants performing VER at 110% PPO. Furthermore, use of VER in adults with heart failure [15], hypertension [29], and metabolic syndrome [14] was described as “feasible” and “well-tolerated” in these populations at risk for or having heart disease. In children with cystic fibrosis [33], it was labeled as “safe.” Although further work is needed to substantiate this, empirical results suggest that VER following GXT is a safe and well-tolerated procedure that does not induce contraindications to exercise testing in persons who are inactive, have known disease, or exhibit enhanced risk of cardiometabolic disease. This guideline encompasses all VER protocols requiring efforts at submaximal, maximal, or supramaximal work rates. The only disadvantage to VER seems to be the extra time commitment required of approximately 15–20 min, including the recovery between protocols. However, this extra time is acceptable if the primary goal of testing is to acquire the most precise estimate of VO2max, which is critical in “at-risk” individuals when VO2max testing is used to identify health status or determine the effects of exercise training.
There are a few limitations to this review. First, the marked diversity in patient populations used and the specific GXT and VER protocol completed preclude us from making universal recommendations regarding an optimal verification test. Nevertheless, it seems that submaximal or supramaximal work rates can be employed with little difference in resultant VO2max values expected versus GXT. Second, with exception of a few studies [11,14,21,31], the sample size of individual studies is relatively small, which reduces the generalizability of these findings. Consequently, we recommend that scientists follow experimental procedures used in single studies that utilized their target population. Third, the use of VER following GXT likely elicits the highest estimate of VO2max on that day, yet it is possible that additional testing on subsequent days could elicit higher estimates of VO2max, as recently shown [38]. However, requiring multiple sessions of exercise including GXT and VER on many days may not be appropriate in unhealthy participants due to time and health related challenges.

5. Conclusions

In conclusion, results from this review demonstrate that verification testing typically leads to similar estimates of VO2max versus prior incremental exercise in unhealthy adults and children having a range of conditions that diminish health status and overall function. This result is informed from verification testing requiring submaximal, maximal, and supramaximal intensities, and it is apparent that each protocol is able to verify VO2max attainment in this particular sample. However, many participants reveal higher VO2max in response to VER compared to GXT, which substantiates its use when the most accurate estimate of VO2max is needed. Moreover, it is a safe and well-tolerated protocol that does not induce contraindications to exercise, and its only shortcoming is the additional time required of the participant. It is evident that some individuals do show higher VO2max in response to verification testing. This merits implementation of this additional test when detecting small differences in VO2max are paramount, for example, to identify potential health risks or describe the efficacy of exercise training in specific clients to augment health status. Failure to do so may lead to inaccurate courses of treatment which may diminish health status of patient populations.

Author Contributions

Conceptualization, T.A.A.; Methodology, T.A.A. and D.E.; Software, T.A.A. and D.E.; Validation, T.A.A.; Formal analysis, T.A.A.; Investigation, T.A.A.; Resources, T.A.A. and D.E.; Data curation, T.A.A. and D.E. Writing—original draft preparation, T.A.A. and D.E.; Writing—review and editing, T.A.A.; Supervision, T.A.A.; Project administration, T.A.A. All authors have read and agreed to the published version of the manuscript.


This research received no external funding.

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

All relevant data are presented in this paper.


The Corresponding Author thanks prior Research Assistants for help in collecting the data reported from his lab in this review.

Conflicts of Interest

The authors declare no conflict of interest.


  1. Blair, S.N.; Kohl, H.W., III; Barlow, C.E.; Paffenbarger, R.S., Jr.; Gibbons, L.W.; Macera, C.A. Changes in physical fitness and all-cause mortality. A prospective study of healthy and unhealthy men. J. Am. Med. Assoc. 1995, 273, 1093–1098. [Google Scholar] [CrossRef]
  2. Garber, C.E.; Blissmer, B.; Deschenes, M.R.; Franklin, B.A.; Lamonte, M.J.; Lee, I.-M.; Nieman, D.C.; Swain, D.P. American College of Sports Medicine position stand. Quantity and quality of exercise for developing and maintaining cardiorespiratory, musculoskeletal, and neuromotor fitness in apparently healthy adults: Guidance for prescribing exercise. Med. Sci. Sports Exerc. 2011, 43, 1334–1359. [Google Scholar] [CrossRef] [PubMed]
  3. Centers for Disease Control, Division of Nutrition, Physical Activity, and Obesity, National Center for Chronic Disease Prevention and Health Promotion. 2020. Available online: (accessed on 13 May 2021).
  4. Schaun, G.Z. The maximal oxygen uptake verification phase: A light at the end of the tunnel? Sports Med. Open. 2017, 3, 44. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  5. Thoden, J. Evaluation of the aerobic power. In Physiological Testing of the High-Performance Athlete; MacDougall, J.D., Wenger, H.A., Green, H.J., Eds.; Human Kinetics: Champaign, IL, USA, 1991. [Google Scholar]
  6. Niemela, K.; Palatsi, I.; Linnaluoto, M.; Takkunen, J. Criteria for maximum oxygen uptake in progressive bicycle tests. Eur. J. Appl. Physiol. Occup. Physiol. 1980, 44, 51–59. [Google Scholar] [CrossRef]
  7. Midgley, A.W.; McNaughton, L.R.; Carroll, S. Verification phase as a useful tool in the determination of the maximal oxygen uptake of distance runners. Appl. Physiol. Nutr. Metab. 2006, 31, 541–548. [Google Scholar] [CrossRef]
  8. Rossiter, H.B.; Kowalchuk, J.M.; Whipp, B.J. A test to establish maximum O2 uptake despite no plateau in the O2 uptake response to ramp incremental exercise. J. Appl. Physiol. 2006, 100, 764–770. [Google Scholar] [CrossRef] [PubMed]
  9. Astorino, T.A.; White, A.C.; Dalleck, L.C. Supramaximal testing to confirm attainment of vo2max in sedentary men and women. Int. J. Sports Med. 2009, 30, 279–284. [Google Scholar] [CrossRef]
  10. Dalleck, L.C.; Astorino, T.A.; Erickson, R.M.; McCarthy, C.M.; Beadell, A.A.; Botten, B.H. Suitability of verification testing to confirm attainment of VO2max in middle-aged and older adults. Res. Sports Med. 2012, 20, 118–128. [Google Scholar] [CrossRef] [PubMed]
  11. Wood, R.E.; Hills, A.P.; Hunter, G.R.; King, N.A.; Byrne, N.M. VO2max in overweight and obese adults: Do they meet the threshold criteria? Med. Sci. Sports Exerc. 2010, 42, 470–477. [Google Scholar] [CrossRef]
  12. Sawyer, B.J.; Tucker, W.J.; Bhammar, D.M.; Gaesser, G.A. Using a verification test for determination of VO2max in sedentary adults with obesity. J. Strength Cond. Res. 2015, 29, 3432–3438. [Google Scholar] [CrossRef]
  13. Astorino, T.A.; De La Rosa, A.B.; Clark, A.; De Revere, J.L. Verification testing to confirm VO2max attainment in inactive women with obesity. Int. J. Exerc. Sci. 2020, 13, 1448–1458. [Google Scholar]
  14. Moreno-Cabañas, A.; Ortega, J.F.; Morales-Palomo, F.; Ramirez-Jimenez, M.; Mora-Rodriguez, R. Importance of a verification test to accurately assess VO2max in unfit individuals with obesity. Scand. J. Med. Sci. Sports 2019, 30, 583–590. [Google Scholar] [CrossRef] [Green Version]
  15. Bowen, S.T.; Cannon, D.T.; Begg, G.; Baliga, V.; Witte, K.K.; Rossiter, H.B. A novel cardiopulmonary exercise test protocol and criterion to determine maximal oxygen consumption in chronic heart failure. J. Appl. Physiol. 2012, 113, 451–458. [Google Scholar] [CrossRef] [Green Version]
  16. Moreno-Cabanas, A.; Ortega, J.F.; Morales-Palomo, F.; Ramirez-Jimenez, M.; Alvarez-Jimenez, L.; Pallarea, J.G.; Mora-Rodriguez, R. The use of a graded exercise test may be insufficient to quantify true changes in VO2max following exercise training in unfit individuals with metabolic syndrome. J. Appl. Physiol. 2020, 129, 760–767. [Google Scholar] [CrossRef]
  17. Costa, V.A.B.; Midgley, A.W.; Carroll, S.; Astorino, T.A.; de Paula, T.; Farinatti, P.; Cunha, F.A. Is a verification phase useful for confirming maximal oxygen uptake in apparently healthy adults? A systematic review and meta-analysis. PLoS. ONE 2021, 16, e0247057. [Google Scholar] [CrossRef]
  18. Blackwell, J.M.; Doleman, B.; Herrod, P.J.J.; Ricketts, S.; Phillips, B.E.; Lund, J.N.; Williams, J.P. Short-term (<8 wk) high-intensity interval training in diseased cohorts. Med. Sci. Sports Exerc. 2018, 50, 1740–1749. [Google Scholar] [CrossRef] [PubMed]
  19. Murias, J.M.; Pogliaghi, S.; Paterson, D.H. Measurement of a true VO2max during a ramp incremental test is not confirmed by a verification phase. Front. Physiol. 2018, 9, 143. [Google Scholar] [CrossRef]
  20. Iannetta, D.; de Almeida-Azevedo, R.; Ingram, C.P.; Keir, D.A.; Murias, J.M. Evaluating the suitability of supra-POpeak verification trials after ramp-incremental exercise to confirm the attainment of maximum O2 uptake. Am. J. Physiol. Regul. Integr. Comp. Physiol. 2020, 319, R315–R322. [Google Scholar] [CrossRef]
  21. Schneider, J.; Schlüter, K.; Wiskemann, J.; Rosenberger, F. Do we underestimate maximal oxygen uptake in cancer survivors? Findings from a supramaximal verification test. Appl. Physiol. Nutr. Metab. 2020, 45, 486–492. [Google Scholar] [CrossRef]
  22. Schaun, G.; Alberton, C.L.; Gomes, M.L.B.; Santos, L.P.; Bamman, M.B.; Mendes, G.F.; Hafele, M.S.; Andrade, L.S.; Alves, L.; De Ataides, V.A.; et al. Maximal oxygen uptake is underestimated during incremental testing in hypertensive older adults: Findings from the HAEL study. Med. Sci. Sports Exerc. 2021, 53, 1452–1459. [Google Scholar] [CrossRef]
  23. Astorino, T.A.; Bediamol, N.; Cotoia, S.; Ines, K.; Koeu, N.; Menard, N.; Nguyen, B.; Olivo, C.; Phillips, G.; Tirados, A.; et al. Verification testing to confirm VO2max attainment in persons with spinal cord injury. J. Spinal Cord. Med. 2019, 42, 494–501. [Google Scholar] [CrossRef] [PubMed]
  24. Leicht, C.A.; Tolfrey, K.; Lenton, J.P.; Bishop, N.C.; Goosey-Tolfrey, V.L. The verification phase and reliability of physiological parameters in peak testing of elite wheelchair athletes. Eur. J. Appl. Physiol. 2013, 113, 337–345. [Google Scholar] [CrossRef]
  25. De Groot, J.F.; Takken, T.; de Graaff, S.; Gooskens, R.H.J.M.; Helders, P.J.M.; Vanhees, L. Treadmill testing of children who have spinal bifida and are ambulatory: Does peak oxygen uptake reflect maximal oxygen uptake? Phys. Ther. 2009, 89, 679–687. [Google Scholar] [CrossRef]
  26. Mahoney, J.M.; Baughman, B.R.; Sheard, A.C.; Sawyer, B.J. Determining the optimal workrate for cycle ergometer verification phase testing in males with obesity. Sports 2021, 9, 30. [Google Scholar] [CrossRef]
  27. Arad, A.D.; Bishop, K.; Adimoolam, D.; Albu, J.B.; DiMenna, F.J. Severe-intensity constant-work-rate cycling indicates that ramp incremental cycling underestimates VO2max in a heterogeneous cohort of sedentary individuals. PLoS ONE 2020, 15, 1–15. [Google Scholar] [CrossRef]
  28. Causer, A.J.; Shute, J.K.; Cummings, M.H.; Shepherd, A.I.; Bright, V.; Connett, G.; Allenby, M.I.; Carroll, M.P.; Daniels, T.; Saynor, Z.L. Cardiopulmonary exercise testing with supramaximal verification produces a safe and valid assessment of VO2max in people with cystic fibrosis: A retrospective analysis. J. Appl. Physiol. 2018, 125, 1277–1283. [Google Scholar] [CrossRef] [Green Version]
  29. Bhammar, D.M.; Chien, L. Quantification and verification of cardiorespiratory fitness in adults with prehypertension. Sports 2021, 9, 9. [Google Scholar] [CrossRef]
  30. Werkman, M.S.; Hulzebos, H.J.; van de Weert-van Leeuwen, P.B.; Arets, H.G.; Helders, P.J.; Takken, T. Supramaximal verification of peak oxygen uptake in adolescents with cystic fibrosis. Pediatr. Phys. Ther. 2011, 23, 15–21. [Google Scholar] [CrossRef]
  31. Misquita, N.A.; Davis, D.C.; Dobrovolny, C.L.; Ryan, A.S.; Dennis, K.E.; Nicklas, B.J. Applicability of maximal oxygen consumption criteria in obese, postmenopausal women. J. Womens Health Gend. Based Med. 2001, 10, 879–885. [Google Scholar] [CrossRef]
  32. Bhammar, D.M.; Stickford, J.L.; Bernhardt, V.; Babb, T.G. Verification of maximal oxygen uptake in obese and nonobese children. Med. Sci. Sports Exerc. 2017, 49, 702–710. [Google Scholar] [CrossRef] [Green Version]
  33. Saynor, Z.L.; Barker, A.R.; Oades, P.J.; Williams, C.A. Reproducibility of maximal cardiopulmonary exercise testing for young cystic fibrosis patients. J. Cyst. Fibros. 2013, 12, 644–650. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  34. Poole, D.C.; Jones, A.M. Measurement of the maximum oxygen uptake (VO2max): VO2peak is no longer acceptable. J. Appl. Physiol. 2017, 122, 997–1002. [Google Scholar] [CrossRef] [PubMed]
  35. Astorino, T.A.; White, A.C. Assessment of anaerobic power to verify VO2max attainment. Clin. Physiol. Funct. Imaging 2010, 4, 294–300. [Google Scholar] [CrossRef]
  36. Astorino, T.A.; DeRevere, J. Efficacy of constant load verification testing to confirm VO2max attainment. Clin. Physiol. Funct. Imaging 2018, 38, 703–709. [Google Scholar] [CrossRef]
  37. Midgley, A.W.; Carroll, S. Emergence of the verification phase procedure for confirming ’true’ VO2max. Scand. J. Med. Sci. Sports 2009, 19, 313–322. [Google Scholar] [CrossRef] [Green Version]
  38. Edgett, B.A.; Bonafiglia, J.T.; Raleigh, J.P.; Rotundo, M.P.; Giles, M.D.; Whittall, J.P.; Gurd, B.J. Reproducibility of peak oxygen consumption and the impact of test variability on classification of individual training responses in young recreationally active adults. Clin. Physiol. Funct. Imaging 2018, 38, 630–638. [Google Scholar] [CrossRef]
Table 1. Summary of studies included in this review.
Table 1. Summary of studies included in this review.
StudyParticipantsAge (Years)BMI (kg/m2)Physical Activity Classification
Leicht et al. [24]24 M wheelchair athletes28 ± 6NRActive
Frederike de Groot et al. [25]20 children with spina bifida10 ± 519 ± 4NR
Mahoney et al. [26]9 M with obesity24 + 633 + 4Recreationally active
Arad et al. [27]35 Sedentary M/W29 ± 4NRInactive
Causer et al. [28]28 M/W with cystic fibrosis31 ± 1222 ± 3NR
Astorino et al. [9]24 Sedentary M/W22 ± 425 ± 2Inactive
Astorino et al. [23]10 M/W SCI
10 M/W AB
33 ± 10 SCI
24 ± 7 AB
23 ± 3 SCI
24 ± 3 AB
Recreationally active
Astorino et al. [13]17 W with obesity37 ± 1039 ± 4Inactive
Bhammar et al. [29]11 M/W with hypertension22 ± 224 ± 3NR
Werkman et al. [30]16 adolescents with
cystic fibrosis
14 ± 218 ± 1NR
Misquita et al. [31]108 W who are Postmenopausal60 ± 633 ± 4Inactive
Bhammar et al. [32]9 NO children
9 OB children
11 ± 118 ± 1 NO
29 ± 4 OB
Bowen et al. [15]24 M with symptomatic CHF64 ± 1130 ± 3NR
Dalleck et al. [10]18 Older M/W59 ± 628 ± 3Recreationally active
Moreno-Cabañas et al. [14]100 M/W with metabolic
57 ± 832 ± 5Inactive
Sawyer et al. [12]19 M/W with obesity35 ± 836 ± 5Inactive
Saynor et al. [33]13 adolescents with
cystic fibrosis
13 ± 321 ± 4NR
Schaun et al. [22]33 adults with hypertension67 ± 532 ± 6NR
Schneider et al. [21]43 W with breast cancer;
32 M with prostate cancer
61 ± 1226 ± 4Recreationally active
Wood et al. [11]135 M/W with Overweight or
37 ± 530 ± 2Inactive
M = men; W = women; BMI = body mass index; OB = obesity; NO = normal weight; NR = not reported; AB = able-bodied; SCI = spinal cord injury.
Table 2. Methodological traits of exercise testing of studies included in this review.
Table 2. Methodological traits of exercise testing of studies included in this review.
StudyExercise ModeTraditional VO2max Criteria AdoptedVO2max ProtocolRecovery Phase ProtocolVER ProtocolVER vs. GXT
Arad et al. [24]CEVO2 plateau;
RER ≥ 1.10;
≥95% HRmax
RAMP 4 min
unloaded cycling + 1 W/3 s for women
1 W/4 s for men
10 min active
recovery at 25 W + 2–3 min passive
100% PPONR
Astorino et al. [9]CENRSTEP
14 W/min for women
21 W/min for men and 5 W/20 s for women and 10 W/20 s for men
1–1.5 h or 24 h later2-min WU at 28 W for women, 42 W for men followed by
cycling at 105 or 115% PPO
Astorino et al. [23]ACEVO2 plateau using individual ΔVO2
values for each
5 min warm-up + 3 W/min for TETRA, 13 W/min for PARA, and 8–20 W/min for AB
10 min active recovery at 7 W2 min at 7 W + arm cycling 105% PPONR
Astorino et al. [13]CENRRAMP
40 W for 2 min + 20 W/min
10 min active
recovery at 20 W
2 min WU at 20 W + cycling at 105% PPOA conservative difference in VO2max between protocols <0.06 L/min was used to identify ‘true’ VO2max
Bhammar et al. [32]CERER ≥ 1.00,
HR ≥ 90% of
age-predicted HRmax
6 min at 40 W + initial WR of 20 W followed by 10–15 W/min
15 min of passive recovery2 min WU at 20 W + cycling at 105% PPOMeasured VER VO2max was considered higher than measured GXT VO2max when difference between measured VER and GXT VO2max was greater than the difference between predicted values
Bhammar et al. [29]CEHR > 85%
age-predicted HRmax;
RER > 1.15
40 W + 20 W/min for women
50 W + 25 W/min for men
15 min passive recovery2 min WU at 30 W for women, 40 W for men + cycling at 105% PPOVER-derived VO2max was higher than incremental VO2max when the difference between measured
VER VO2max and incremental
VO2max was greater
than the difference between predicted VER and
incremental VO2max
Bowen et al. [15]CEBLa > 8 mM;
HR within 10% of age-predicted HRmax;
RPE > 18;
RER > 1.00–1.15
4 min at 10 W +
4–18 W/min
5 min active recovery at 10 W4 min WU at 10 W + cycling at 95% PPONR
Causer et al. [28]CEVO2 plateau;
RPE > 9;
RER > 1.03–1.05;
Predicted VO2peak, PPO, or HRpeak
3 min at 20 W +
10–25 W/min
5 min cool-down at 20 W +10 min seated rest3 min WU at 20 W +
cycling at 110% PPO
Less than 9% difference between protocols
Dalleck et al. [10]CERER > 1.0–1.15;
HR within 10 b/min of age-predicted HRmax;
VO2 plateau
STEP2 min WU at 50 W + 10–15 W/min60 min passive
2 min WU at 50 W + cycling at 105% PPOLess than 3%
difference in VO2max between tests
de Groot et al. [25]TMHeart rate = 95% (210–age);
RER > 1.0;
VO2 plateau
2% grade + 2 km/h + 0.25% change in grade/min or 3 km/h + 0.50% change in grade per min
4 min passive
110% peak speedDifference in VO2max between protocols >2.1 mL/kg/min
Leicht et al. [24]TMVO2 plateau;
RER > 1.05
BLa > 4.0 mM;
HR > 85%
age-predicted HRmax
Constant speed at 1% grade and grade
increased by 0.1–0.3%/min
5 min active recovery at 1 m/s at 1% gradeSame peak speed as GXT but
gradient (+0.6% for PARA and NON-SCI; +0.3% for TETRA)
Mahoney et al. [26]CENRRAMP
5 min WU at 20 W before power continuously increased that was individualized for each participant
At least 2 days later2 min rest + 5 min WU at 50 W +
cycling at 80–105% PPO
Misquita et al. [31]TMHRmax > 220–age; RER > 1.1;
VO2 plateau
Bruce protocol
1–2 min of slow walking +2 min at
0% incline at a speed eliciting 70%HRmax
Balke protocol TM grade was increased to 4% for 2 min and increased 2%/minNR
Moreno-Cabañas et al. [14]CEVO2 plateau;
RER > 1.1;
BLa 8 mM;
HR < 5% from
age-predicted HRmax
3-min WU at 30 W for women, 50 W for men + 15–20 W/min
5 min active recovery at 30 W + 15 min seated recovery2 min WU at 30 W for women, 50 W for men + cycling at 110% PPONR
Sawyer et al. [12]CENRRAMP
5 min WU 50 W + 30 W/min for men
25 W + 15 W/min for women
Active recovery for 5–10 min at 25 or 50 W100% PPO
Saynor et al. [33]CENRRAMP
3 min at 20 W + 10–25 W/min
5 min active recovery at 20 W + 10 min passive seated recovery3 min at 20 W + cycling at 110% PPONR
Schaun et al. [22]TMΔVO2 ≤ 150 mL/min; RER > 1.10; RPE ≥ 18; ± 10 b/min of 220–ageSTEP
3 min at 3 km/h + 0.5 km/h and 1% increments in speed and grade
10 min of passive recovery2 min at 50% of peak speed/grade + 1 min at 70% peak speed/grade + exercise at 1 stage higher than GXTDifference in VO2max between protocols < 3%
Schneider et al. [21]CERER ≥ 1.1;
HRmax ≥ 200 b/min–age
BLamax ≥ 8 mM;
RPE ≥ 18
20 W + 10 W/min
10 min passive recoverycycling at 110% PPOVO2max in VER does not exceed GXT-derived value by >3%
Werkman et al. [30]CEVO2 plateau;
HR > 95%
age-predicted HRmax; RER > 1.0
Unloaded cycling + 10 W/min < 120 cm; 15 W/min 120–150 cm; 20 W/min > 150 cm
1 min passive recovery + 1 min unloaded cyclingTest started with an increase in PO every 10 s based on each participant’s heightNR
Wood et al. [11]TMVO2 plateau;
HR ± 11 b/min of age-predicted HRmax
RER ≥ 1.15;
BLa ≥ 8 mM;
RPE ≥ 18
4 min at 5.6 km/h −1 and 0% grade + increased velocity to a speed consistent with face-paced walk slow jog + 2.5% change in grade/min
5–10 min passive recovery0.5 km/h above maximum workload in GXT achieved through increases in speed and/or gradeChange in VO2 < 50% of that expected for the change in mechanical work
RAMP = ramp protocol; STEP = step protocol; CE = cycle ergometry; TM = treadmill; WU = warm-up; HR = heart rate; RER = respiratory exchange ratio; VER = verification test; VO2 = oxygen uptake; GXT = graded exercise test; BLa = blood lactate concentration; RPE = rating of perceived exertion; ACE = arm cycle ergometry.
Table 3. Results from studies included in this review.
Table 3. Results from studies included in this review.
StudyVO2max GXT
GXT Duration (min)VO2max VER
VER Duration (min)HRmax GXT (b/min)HRmax VER (b/min)Results
Arad et al. [27]28 ± 69.6 ± 1.630 ± 7 *2.6 ± 0.5170 ± 12172 ± 9VER elicited a higher VO2peak versus GXT, although there was no difference in HRpeak.
Astorino et al. [9]32 ± 410.5 ± 1.632 ± 52.7 ± 0.7191 ± 9 *187 ± 10There was no difference in VO2max between protocols, yet several participants demonstrated a higher VO2max in response to VER. GXT revealed a higher HRmax versus VER.
Astorino et al. [23]17 ± 4 SCI
24 ± 4 AB
7.4 ± 1.417 ± 4 SCI
26 ± 4 * AB
1.7 ± 0.3161 ± 29
176 ± 17
160 ± 26
178 ± 12
Mean VO2peak from VER was higher than GXT in the AB group, although VO2peak was similar across protocols in SCI. There was no difference in HRpeak across all groups between protocols.
Astorino et al. [13]2.0 ± 0.4 L/minNR2.0 ± 0.3 L/min1.5 ± 0.3174 ± 13174 ± 12There was no difference in VO2max or HRmax between protocols, although 5, 9, and 7 women revealed a verification VO2max > 0.06 L/min higher versus GXT.
Bhammar et al. [32]40 ± 4 NO
27 ± 4 OB
9.7 ± 2.443 ± 4 * NO
28 ± 3 OB
2.2 ± 0.5189 ± 6 NO
190 ± 13 OB
184 ± 8 NO
188 ± 12 OB
All children exhibited higher mean VER VO2max versus GXT, although there was no difference in HRmax.
Bhammar et al. [29]31 ± 6NR32 ± 62.1 ± 0.3180 ± 11180 ± 7There was no difference in VO2max or HRmax between protocols, yet 3 of 11 participants exhibited a higher VO2max during VER compared to GXT.
Bowen et al. [15]14 ± 35.8–15.1 ± 0.5–1.915 ± 32.0 ± 0.4117 ± 20119 ± 26Mean VO2peak and HRpeak were not different between protocols and VO2peak was confirmed in 60% of participants.
Causer et al. [28]35 ± 89.3 ± 2.333 ± 71.5 ± 0.4168 ± 15NRMean VO2peak did not differ between protocols, yet VER VO2peak was higher than GXT in 21% of participants.
Dalleck et al. [10]28 ± 610.1 ± 2.127 ± 62.5 ± 0.5165 ± 11164 ± 10Mean VO2max and HRmax were not different between protocols, although 11% of subjects exhibited higher VO2max and HRmax values with VER.
Frederike de Groot et al. [25]34 ± 89.0 ± 4.035 ± 8NR184 ±20NRMean VO2peak was similar between protocols, yet 25% and 42% of participants showed a higher VO2peak and HRpeak in VER versus GXT.
Leicht et al. [24]23–40 ± 3–68.5–10.5 ± 0.5–2.5NRNR125–188 ± 7–10125–181 ± 7–15VO2peak and HRpeak did not differ between VER and GXT in all subgroups. Athletes tended to exhibit a lower VO2peak in response to VER versus GXT.
Mahoney et al. [26]3.4 ± 0.4 L/min8.3 ± 0.43.4–3.6 ± 0.5 L·min−12.5–6.9 ± 0.4–2.5175 ± 12170–177 ± 13–17VER performed at 90% PPO elicits greater VO2max versus GXT, yet there was no difference in HRmax.
Misquita et al. [31]19 ± 38.8 ± 1.920 ± 3 *8.5 ± 1.9156 ± 15158 ± 14VER revealed higher VO2peak versus GXT, although HRpeak was similar.
Moreno-Cabañas et al. [14]23 ± 87.9 ± 2.025 ± 8 *2.1 ± 0.4155 ± 15156 ± 15VER-derived VO2peak was higher than GXT, although there was no difference in HRpeak. Forty percent of participants show underestimated VO2peak in response to GXT that is confirmed with VER.
Sawyer et al. [12]2 ± 1 L·min−17.1 ± 1.92 ± 1 L·min−11.9 ± 0.4174 ± 16177 ± 13 *Mean VO2max was not different between protocols, yet HRmax was higher in VER. Thirteen and 8 participants achieved a VO2max and HRmax in response to VER that was ≥2% and 4–14 b/min higher than GXT.
Saynor et al. [33]34 ± 38–12NRNR187 ± 15NRVO2max values are reproducible in this sample in response to GXT and VER.
Schaun et al. [22]22 ± 512 ± 224 ± 6 *4.7 ± 0.4150 ± 16152 ± 16VO2max was higher in response to VER versus GXT, although there was no difference in HRmax.
Schneider et al. [21]21 ± 413.0 ± 2.921 ± 5 *2.2 ± 0.3150 ± 20151 ± 21VO2max from VER was lower than GXT, although there was no difference in HRmax. Sixty-eight percent of participants showed a ‘true’ VO2max with VER, although 32% elicited a 3–21% higher VO2max.
Werkman et al. [30]39 ± 711.0 ± 3.039 ± 94.0 ± 1.0177 ± 12179 ± 13There was no difference in VO2peak or HRpeak between protocols.
Wood et al. [11]34 ± 78–1234 ± 7NR180 ± 10180 ± 10Neither VO2peak nor HRpeak were different between protocols.
VO2max = maximal oxygen uptake; GXT = graded exercise test; VER = verification test; HR = heart rate; NO = normal weight; OB = obese; * = p < 0.05 between protocols.
Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Share and Cite

MDPI and ACS Style

Astorino, T.A.; Emma, D. Utility of Verification Testing to Confirm Attainment of Maximal Oxygen Uptake in Unhealthy Participants: A Perspective Review. Sports 2021, 9, 108.

AMA Style

Astorino TA, Emma D. Utility of Verification Testing to Confirm Attainment of Maximal Oxygen Uptake in Unhealthy Participants: A Perspective Review. Sports. 2021; 9(8):108.

Chicago/Turabian Style

Astorino, Todd A., and Danielle Emma. 2021. "Utility of Verification Testing to Confirm Attainment of Maximal Oxygen Uptake in Unhealthy Participants: A Perspective Review" Sports 9, no. 8: 108.

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop