SciELO - Scientific Electronic Library Online

 
vol.30 número4Força de preensão manual, nível de atividade física e qualidade de vida de competidores máster de judôDiferentes ordens do exercício combinado: efeitos agudos de 24 horas sobre a pressão arterial de atletas índice de autoresíndice de assuntospesquisa de artigos
Home Pagelista alfabética de periódicos  

Serviços Personalizados

Journal

Artigo

Indicadores

Links relacionados

Compartilhar


Revista Brasileira de Educação Física e Esporte

versão impressa ISSN 1807-5509versão On-line ISSN 1981-4690

Rev. bras. educ. fís. esporte vol.30 no.4 São Paulo out./dez. 2016

http://dx.doi.org/10.1590/1807-55092016000400857 

BIODINÂMICA

The VO2max plateau is not associated with the anaerobic capacity in physically active subjects

Renata Gonçalves SILVA* 

Marcos David SILVA-CAVALCANTE*  ** 

Rafael de Almeida AZEVEDO* 

Adriano Eduardo LIMA-SILVA** 

Rômulo BERTUZZI* 

*Escola de Educação Física e Esporte, Universidade de São Paulo, São Paulo, SP, Brasil.

**Centro Acadêmico de Vitória, Universidade Federal de Pernambuco, Vitória de Santo Antão, PE, Brasil.

Abstract

The present study aimed to verify if the incidence of plateau is associated with anaerobic capacity. Therefore, nine physically active male (age: 23 ± 4 yr; body mass: 72.4 ± 8.2 kg; height: 176.4 ± 6.8 cm; VO2max: 41.3 ± 5.7 ml.kg-1.min-1) participated in the present study. The subjects in a cycle ergometer the following tests: a) maximum incremental test to determination of VO2max; b) six submaximal tests for determination of supra maximum demand of O2; c) supra maximum test for maximum accumulated oxygen deficit (MAOD) determination. The plateau was identified when the difference in the VO2 in the last two stages of incremental test was ≤ 2.1 ml.kg-1.min-1. It was observed an inverse correlation, although no significant, between MAOD and VO2 plateau (r = -0,61; p > 0,05). Thus, it appears that anaerobic capacity is not a decisive factor for determining the incidence of VO2 plateau in physically active individuals.

Key words: MAOD; Oxygen deficit; Stabilization of oxygen uptake; Incremental test; Supra maximum test

Introduction

Traditionally, maximum oxygen consumption (VO2max) has been used to represent the maximum aerobic capacity1-2. Presently, VO2max is used as an indicator of cardiorespiratory fitness3-8, running performance predictor6-8, to evaluate training related adaptations in healthy individuals9 and in patients with coronary arterial disease10, detraining11-12, mortality predictor13 and to evaluate sleeping disorder14. Thereby, VO2max identification is important to evaluate the fitness levels in athletes as well as in high-risk groups. VO2max is measured via incremental tests (TI), usually performed to voluntary exhaustion. Although several variables have been considered in order to establish maximum effort2, the main characterization of VO2max is through stabilization in oxygen consumption (VO2) during the final stages of TI. This VO2 characterization during the final stages of TI has been termed VO2 plateau2. Theoretically, plateau refers to a stabilization or small increases (≤ 2.1 ml.kg-1.min-1) of VO2, even if loads are incremented in the final stages of TI2. However, some tests are interrupted before reaching VO2max. In this case, the value obtained is termed as peak oxygen consumption (VO2peak)15. It has been suggested that plateau incidence may be related to athlete’s training state, in which athletes with higher physical condition could tolerate higher levels of pain and fatigue and higher motivation to support higher loads in the final test16-17, and that the higher intensities could be related to increases in energy supply by the anaerobic metabolism1.

Provided the relevance to establish VO2max parameters, previous studies used one additional test to confirm if VO2 value, obtained in a traditional TI protocol, could be considered as maximum18-19. The confirmation test is performed until fatigue with constant loads and intensities near to the VO2max. For instance, SNELL et al.19 performed the confirmation test with two intensities (95% and 105% of the maximum power in TI) and, in both conditions, it were not observed significant differences between VO2 in the verification test and the VO2max achieved in TI, even in the absence of plateau. This result suggest that the maximum aerobic power can be achieved during TI, even if there is no plateau in VO2.

Previous studies with trained individuals have suggested that VO2 plateau may be related to the anaerobic metabolism1. During high-intensities exercises, the ATP resynthesizes occurs predominantly via anaerobic metabolism, which seems to justify, in the final stages of the incremental test, an increase in exercise intensity even with no modifications VO2 (stabilization). In a recent study, GORDON et al.1 showed a negative correlation between ΔVO2 and maximum accumulated oxygen deficit (MAOD) in highly trained cyclists. These results indicate that individuals with higher anaerobic capacity have higher incidence of plateau. Given that MAOD is elevated in both aerobic and anaerobic trained individuals as compared with physical active ones20, it seems plausible to suggest a lower incidence of VO2 plateau in physical active and non-athletes individuals. However, to the present moment no study analyzed the relationship between anaerobic capacity and the VO2 plateau in individuals with low levels of physical condition.

Thus, the present study aimed to verify the relationship between anaerobic capacity measured via MAOD and the incidence of VO2 plateau in physical activity individuals. The hypothesis was that there would be positive correlations between MAOD and VO2 plateau.

Method

Subjects

Nine male subjects participated in the present study 23 ± 4 years, 72.4 ± 8.2 kg e 176.4 ± 6.8 cm). They were physically active, healthy and had previous experience with exhaustion exercise. All participated in recreational sports and activities (running, soccer and tennis), however, none were engaged in competitive activities. All subjects were informed about the aims, procedures and possible risks associated with the present study and gave their informed consent prior to enrolment in the study. All subjects were free from pharmacological treatments, neuromuscular or cardiovascular disease and were non-smokers. The present study was approved by the commit of ethical research of the School of Physical Education and Sport of the University of Sao Paulo.

Experimental design

All subjects were submitted to four experimental sessions, with at least 72 h of interval between sessions. In the first session, subjects performed an incremental test to voluntary exhaustion in a cycle ergometer to measure VO2max and its respective VO2max power (WVO2max). In the following sessions (i.e., second and third) subjects were submitted to six tests with constant loads (3 tests per session) with intensities below VO2max. Sessions as well as sub-VO2max tests order was randomized between subjects. Tests were performed in a controlled environment with constant room temperature (20-24 ºC) and with two hours of interval from the last meal. Subjects were instructed not to performed strenuous physical exercises and not to consume alcohol 48 hours before data collection. In order to avoid any possible effect of ergogenic21 and circadian cycle22, all tests were performed in the same period of the day and subjects were instructed to not consume caffeine 48 hours before tests.

Anthropometric measures

Body mass and height were measured via an electronic scale (Filizola, model ID 1500, São Paulo, Brazil) and a wood stadiometer, respectively.

Incremental test

Incremental test was performed in an electromagnetic cycle ergometer for lower limbs (Godart-Holland, Lannoy). Immediately before test, subjects remained seated on the cycle ergometer for five minutes to determine baseline VO2 (VO2LB). The VO2LB refers to rest VO2, which was determined from the arithmetic mean of VO2 during the final 30 seconds of the rest. Three minutes after warm-up, with the inertial resistance from the equipment, subjects cycled with a cadence of 60 rpm and increments of intensity of 30 W.min-1. Test was interrupted when cadence was lower than 50 rpm. Throughout test, exchange gas and heart rate (HR) were measured breath-by-breath and beat-by-beat, respectively. VO2 was measured continuously via a portable gas analyzer (K4b2 Cosmed, Rome, Italy), whereas the HR was assessed by heart rate monitor (Polar, Kempele, Finland). Maximum heart rate (HRmax) was established as the higher values obtained in the final test. VO2max was determined according to at least three of the five criterion: increases in VO2 lower than 2.1 ml.kg-1.min-1 regardless of increases in exercise intensity; subjects’ voluntary exhaustion; respiratory exchange ratio higher than 1.10; blood lactate concentration after test higher than 8.0 mmol.l-1; maximum heart rate predicted by age (220-age)2. VO2 plateau was determined when the difference in oxygen consumption during the last 30 seconds in the last two final stages was ≤ 2.1 ml.kg-1.min-1. WVO2max was established as the maximum power at VO2max value.

Test with constants loads

The cycle ergometer, saddle height, pedal pace, warm-up, interruption criterion and VO2 measurement in the exercises with constants loads were the same as in the progressive test until exhaustion. Subjects exercised for ten minutes, or until voluntary exhaustion, in six tests with intensities below the WVO2max: 40, 50, 60, 70, 80 and 90% of WVO2max and one above WVO2max (110 WVO2max). The rest interval between tests was approximately ten minutes, or until subjects return to VO2LB values. Mean VO2 values during the last minute of the test was used to represent the VO2 in these tests.

Calculations

The arithmetic mean of VO2 during the last 30 seconds in the sub-WVO2max exercises was plotted with its respective intensities in order to develop individuals’ linear regression equations. The angular coefficients produced by these equations were used to estimate the oxygen demand (VO2DEM) in the supra-WVO2max exercise (equation described below). The trapezium method was used to calculate VO2 area in respect to the duration time of supra-WVO2max exercise. After that, accumulated VO2 (VO2ACUM), that is, the area under the curve of VO2-time, was determine from the VO2LB10. The MAOD was established as the VO2DEM minus VO2ACUM.

VO2DEM = [(b*110/60).t]

Where VO2DEM is the estimated O2 demand during supra-WVO2max exercise; 110 is the intensity of the supra-WVO2max exercise; b is the angular coefficient in 1.min-1 obtained from the linear regression in the VO2-intensities in the sub-WVO2max tests; t is the total duration time of exercise expressed in seconds.

Statistical analyses

All analyses were performed with the SPSS software (version 13.0, Chicago, USA). Data normality was verified by Shapiro-Wilk test and all presented normal distribution. Data are reported as means and standard deviation (SD). The correlation coefficient between ΔVO2 and MAOD was determined with Pearson linear correlation. VO2max and the 90% VO2 of the WVO2max values were compared by a paired T test. The unpaired T test was used for between-group comparisons (plateau vs. non-plateau) for all the dependent variables (VO2max, MAOD, peak power, peak heart rate, respiratory exchange ratio [R], peak blood lactate concentration, ventilatory threshold of VO2, and % of ventilatory threshold of VO2 related to VO2peak). The level of significance adopted was 5% (p < 0.05).

Results

Variables related to the progressive test are presented in TABLE 1. It was not observed significant differences between VO2max and VO2peak obtained at 90% of WVO2max (p > 0.05).

TABLE 1 Variables obtained during the progressive test (n = 9). 

VO2max (l.min-1) 3.0 ± 0.5
VO2max (ml.kg-1.min-1) 41.3 ± 5.7
Respiratory Exchange ratio (R) 1.29 ± 0.09
Maximum power (Watts) 247 ± 39
Total duration time (min) 8 ± 1
Maximum heart rate (bpm) 180 ± 9
[La-] peak (mmol.l-1) 10.3 ± 1.4

Values are presented as mean ± standard-deviation. VO2max: maximum oxygen consumption; [La-]peak: peak blood lactate concentration.

The between-group comparisons revealed no significant differences for the dependent variables: maximum oxygen consumption (VO2max), peak power, peak heart rate, respiratory exchange ratio, peak blood lactate concentration, VO2 at the ventilatory threshold and % of the VO2 of the ventilatory threshold in respect to VO2max (TABLE 2).

TABLE 2 Between-group comparisons (plateau vs. non-plateau) for the progressive test variables. 

Grupo platô Grupo sem platô
VO2max (ml.kg-1.min-1) 41.9 (3.9) 40.6 (8.7)
Peak power (W) 264 (39) 225 (30)
WVT 180 (36.7) 172.5 (28.7)
VO2VT 31.0 (2.1) 34.1 (5.5)
VT (%VO2max) 74.6 (8.2) 84.7 (5.7)
R 1.28 (0.11) 1.32 (0.03)
Peak lactate (mmol.l-1) 10.8 (0.9) 10.1 (1.8)
Peak heart rate (bpm) 180 (6) 178 (14)

VO2max: maximum oxygen consumption; WVT: power ventilator threshold; VO2VT: oxygen consumption at ventilatory threshold; VT: ventilatory threshold; R: respiratory exchange ratio.

Five out of nine subjects presented VO2 plateau (55% of the subjects). The correlation analysis in these subjects (FIGURE 1, left panel) showed a non-significant inverse correlation between Δ VO2 and MAOD (r = -0.61, p = 0.270). Similar non-significant result was observed when pooling data from all subjects (r = 0.28; p = 0.464).

The left panel refers to subjects that presented plateau, whereas the right panel represent all subjects (plateau and non-plateau).

FIGURE 1 Coefficient correlation between rate of increase in oxygen consumption (ΔVO2max) and maximum accumulated oxygen deficit (MAOD). 

Discussion

The aim of the present study was to verify the relationship between anaerobic capacity and VO2 plateau incidence in physically active subjects. Our hypothesis was that MAOD would be positively associated with VO2 plateau. However, the results from the present study showed that VO2 plateau incidence does not seems to be associated with the anaerobic capacity in physically active subjects.

The VO2max has been utilized to assess the maximum aerobic power1-2. The presence of plateau is considered a key criterion to determine if the value obtained during the test can be considered as maximum19. However, not all subjects are capable to achieve plateaus state. Previous studies demonstrated a high heterogeneity of plateau incidence between 12 to 59%1,18,23-26. Studies in highly trained athletes showed similar or even lower percentage of plateau incidence as in the present study. Lucia et al.25 reported a plateau incidence of 47% in elite professional cyclists, whereas DOHERTY21 showed a plateau incidence of 25% and 39% for men and women, respectively in Olympic athletes runners of medium and long distance. In the present study, five out of nine subjects presented plateau. These results are similar to GORDON et al.1 that observed plateau presence in four out of nine (44.4%) highly training cyclists.

In the present study, we observed a non-significant correlation between MAOD and ΔVO2, which do not corroborate with the above-mentioned study1, given that it was observed a significant negative correlation between variables (r = -0.77, p = 0.008) in highly trained cyclists that presented plateau (VO2max = 59.3 ± 4.8 ml.kg-1.min-1). This result suggest that, in physically active subjects, others variables seems to affect the plateau incidence, in addition to the anaerobic capacity. It has been suggested that the plateau incidence is associated with the individual capacity to support high levels of fatigue and its resistance to pain16. However, highly trained athletes, which are familiarized with high levels of effort and pain sensation during training session and/or competitions, did not show higher incidence of plateau21,25, strengthening the idea of other intervening variables. PETOT et al.17 have suggested that the incapacity to reach plateau in incremental test is due to the incapacity to support the high power levels demanded during the test final stages. In their study, an incremental test was performed to verify the VO2max. For the subjects that presented plateau or for those that the secondary criterion was achieved, even in the absence of plateau, a new test was performed. Test started similarly to the incremental test, with increases in load in a time function. When subjects achieved its VO2max, determined in the first test, the power was reduced until the subject was able to maintain the VO2 values previously determined. Using this protocol, 100% of subjects were able to reach plateau. Another study that corroborate with the present results is the RIVERA-BROWN et al.23 where the incidence of plateau in pre-pubertal boys was 33% and, it was not observed any relationship between anaerobic power and plateau incidence. This results seems reinforce that other variables may be relevant to plateau incidence, as children’s shown lower anaerobic capacity levels, thus, it would be expected a reduced incidence of plateau.

Additionally, results from the present study demonstrated that VO2 peak at 90% of WVO2max was not significant different from VO2max. That is, the VO2 values obtained during the final TI can be considered as maximum, even for those subjects that did not reach plateau. Indeed, exercise performed within this level of effort (~90% of WVO2max) usually achieve the VO2max values27. Furthermore, peak heart rate, R and blood lactate concentrations reached elevated values, confirming that the values observed can be considered as maximum for all subjects2. It was also demonstrated that individuals with higher levels of maximum aerobic power did not present a higher incidence of plateau. Altogether, these results suggests that when physically active subjects reach the first load correspondent to VO2max they interrupt the exercise.

Importantly, the present study has some limitations. First, only nine subjects were evaluated, which could have been insufficient to observe significant correlations between variables. Especially in the sub-analysis, in which it was considered only the subjects that presented plateau (n = 5). In this analysis we observed a negative correlation, however, it was not statistical significant. In order to observe significant correlations with small sample sizes it is necessary values nears of one (+1 or -1), which increase the chance for type II error (observe non-significant correlations between variables, when in fact there is significant correlations)28. Limitations related to the use of MAOD to determine the anaerobic capacity should be highlighted, an impossibility to directly measure the variable, due to a lack of gold-standard method to determine the anaerobic capacity; the use of VO2 to estimate the energetic metabolism that is measured as the whole-body, not being possible to account for the demand imposed by the musculoskeletal system during the exercise task; the contribution of the anaerobic lactic system on intensities above the anaerobic threshold are not excluded of the calculations and the slow component of VO2 during the higher intensities may overestimate the O2 demand. Despite these limitations, the MAOD has been considered as a decent method to estimate the anaerobic capacity6,29-30.

In short, it was observed non-significant correlations between plateau and anaerobic capacity, suggesting that the plateau incidence it is not related only with the anaerobic capacity in physically active subjects. Altogether, these results indicate that for subjects with this level of training, the anaerobic capacity it is not the main predominant factor to plateau incidence.

Referências

1. Gordon D, Hopkins S, King C, Keiller D, Barnes RJ. Incidence of plateau at VO2max is dependent on the anaerobic Capacity. Int J Sports Med. 2011;32:1-6. [ Links ]

2. Howley ET, Basset DT, Welch HG. Criteria for maximal oxygen uptake: review and commentary. Med Sci Sports Exerc. 1995;27:1292-301. [ Links ]

3. Shephard RJ, Allenm C, Benade AJ, et al. The maximum oxygen intake: an international reference standard of cardio-respiratory fitness. Bull World Health Organ. 1968;38:757-64. [ Links ]

4. Basset DR, Howley ET. Limiting factors for maximum oxygen uptake and determinants of endurance performance. Med Sci Sports Exerc. 2000;32:70-84. [ Links ]

5. Howley TH, Basset DR. Criteria for maximal oxygen uptake: review and commentary. Med Sci Sports Exerc. 1995; 27:1292-301. [ Links ]

6. Bertuzzi R, Bueno S, Pasqua LA, et al. Bioenergetics and neuromuscular determinants of the time to exhaustion at velocity corresponding to VO2max in recreational long-distance runners. J Strength Cond Res. 2012; 26:2096-102. [ Links ]

7. Nummela TA, Paavolainen LM, Sharwood KA, Lambert MI, Noakes TD, Rusko HK. Neuromuscular factors determining 5 km running performance and running economy in well-trained athletes. Eur J Appl Physiol. 2006;97:1-8. [ Links ]

8. Brandon LJ. Physiological factors associated with middle distance running performance. Sports Med. 1995;19:268-77. [ Links ]

9. Hickson RC, Bomze HA, Holloszy JO. Linear increase in aerobic power induced by a strenuous program of endurance exercise. J Appl Physiol Respir Environ Exerc Physiol. 1977;42:372-6. [ Links ]

10. Warburton DE, McKenzi DC, Haykowsky MJ, et al. Effectiveness of high-intensity interval training for the rehabilitation of patients with coronary artery disease. Am J Cardiol. 2005;95:1080-4. [ Links ]

11. Melchiorri G, Ronconi M, Triossi T, et al. Detraining in young soccer players. J Sports Med Phys Fitness. 2014;54:27-33. [ Links ]

12. Neufer PD. The effect of detraining and reduced training on the physiological adaptations to aerobic exercise training. Sports Med. 1989;8:302-20. [ Links ]

13. Keteyian SJ, Brawner CA, Savage PD, et al. Peak aerobic capacity predicts prognosis in patients with coronary heart disease. Am Heart J. 2008;156:292-300. [ Links ]

14. Beitler JR, Awad KM, Bakker JP, et al. Obstructive sleep apnea is associated with impaired exercise capacity: a cross-sectional study. J Clin Sleep Med. 2014;10:1199-204. [ Links ]

15. Day JR, Rossiter HB, Coats EM, Skasick A, Whipp BJ. The maximally attainable VO2 during exercise in humans: the peak vs. maximum issue. J Appl Physiol. 2003;95:1901-7. [ Links ]

16. Wagner PD. New ideas on limitations to VO2max. Exerc Sport Sci Rev. 2000;28:10-4. [ Links ]

17. Petot H, Meilland R, Moyec LL, Mille-Hamard L, Billat VL. A new incremental test for VO2max accurate measurement by increasing VO2max plateau duration allowing the investigation of its limiting factors. Eur J Appl Physiol. 2012;112:2267-76. [ Links ]

18. Rossiter HB, Kowalchuck JM, Whipp BJ. A test to establish maximum O2 uptake despite no plateau in the O2 uptake response to ramp incremental exercise. J Appl Physiol. 2006;100:764-70. [ Links ]

19. Snell PG, Stray-Gundersen J, Levine BD, Hawkins MN, Raven PB. Maximal oxygen uptake as a parametric measure of cardiorespiratory capacity. Med Sci Sports Exerc. 2007;39:103-7. [ Links ]

20. Gastin PB, Costill DL, Lawson DL, Krzeminski, K, McConell G. Accumulated oxygen deficit during supramaximal all-out and constant intensity exercise. Med Sci Sports Exerc. 1995;27:255-63. [ Links ]

21. Doherty M. The effects of caffeine on the maximal accumulated oxygen deficit and short-term running performance. Int J Sport Nutr. 1998;8:95-104. [ Links ]

22. Marth PD, Woods RR, Hill DW. Influence on time of day on anaerobic capacity. Percept Mot Skills. 1998;86:592-4. [ Links ]

23. Rivera-Brown AM, Alvarez M, Rodríguez-Santana JR, Benetti PJ. Anaerobic power and achievement of VO2 plateau in pre-pubertal boys. Int J Sports Med. 2011;22:111-5. [ Links ]

24. Doherty M, Nobbs L, Noakes TD. Low frequency of the “plateau phenomenon” during maximal exercise in elite British athletes. Eur J Appl Physiol. 2003;89:619-23. [ Links ]

25. Lucía A, Rabacán M, Hoyos J, et al. Frequency of the VO2max plateau phenomenon in world-class cyclists. Int J Sports Med. 2006;27:984-92. [ Links ]

26. Astorino TA. Alterations in VO2max and VO2 plateau with manipulation of sampling interval. Clin Physiol Funct Imaging. 2009;29:60-7. [ Links ]

27. Bertuzzi RCM, Rumenig-Souza E. Resposta cinética do consumo de oxigênio: relação entre metabolismo aeróbio e atp-cp. Arq Mov. 2009;5:99-118. [ Links ]

28. Thomas JR, Nelson JK. Métodos de pesquisa em atividade física. Porto Alegre: Artmed; 2002. [ Links ]

29. Scott CB, Roby FB, Lohman TG, Bunt JC. The maximally accumulated oxygen deficit as an indicator of anaerobic capacity. Med Sci Sports Exerc. 1991;23:618-24. [ Links ]

30. Gastin, PB. Quantification of anaerobic capacity. Scand J Med Sci Sports. 1994;4:91-112. [ Links ]

Received: June 10, 2014; Revised: March 18, 2015; Revised: August 04, 2015; Accepted: September 29, 2015

ENDEREÇO. Renata Gonçalves Silva. Escola de Educação Física e Esporte - USP. Av. Prof. Mello de Moraes, 65. 05508-030 - São Paulo - SP - BRASIL. e-mail: resilva@usp.br

Creative Commons License  This is an Open Access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.