How to Seek the Oxygen Uptake Plateau Volume 45 - Issue 2

Rodolfo Velasque¹* and Fernando A M S Pompeu^1,2

• ¹Biometrics Laboratory, College of Physical Education and Sports at Rio de Janeiro Federal University (LADEBIO/EEFD/UFRJ), Brazil
• ²Physical Education Graduate Program at Rio de Janeiro Federal University (PPGEF/UFRJ), Brazil

Received: July 20, 2022;   Published: July 26, 2022

*Corresponding author: Rodolfo Velasque, Biometrics Laboratory, College of Physical Education and Sports at Rio de Janeiro Federal University (LADEBIO/EEFD/UFRJ) - 540, Carlos Chagas Avenue, zip code 21941-590, Rio de Janeiro, Brazil

DOI: 10.26717/BJSTR.2022.45.007185

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Keywords: Maximal Oxygen Uptake; Exercise Test; Cardiovascular Health; Physical Performance

The maximal oxygen uptake (νο_2max) is an important physiological parameter, which is associated with the cardiorespiratory health, physical fitness and athletic performance. The νο_2max is defined as the maximal capacity of inhaling, transporting and utilising oxygen in the energetic metabolism during the maximal effort. Therefore, this parameter is limited by cardiovascular transport capacity of the oxygen from the lungs to the active muscles. Moreover, a high level of the νο_2max is an important prerequisite for the elite endurance performance [1-3]. A plateau of the oxygen uptake (νο_2pl) is the gold standard criterion to establish the νο_2max . This criterion means a levelling of the 2 νο near the maximal effort, although the workload has still been increasing. If the 2 νο measurements do not increase more than 150 mL·min-1 (or 2 mL·kg-1·min-1) with the workload increments, then the plateau is achieved [4]. The νο_2pl is a physiological phenomenon, even though it is not seen in a large number of subjects who are submitted to the maximal effort test. This νο_2pl absence can mainly be caused by a wrong choice of the test protocol. This mistake is made when a researcher intends to save time or to give priority to another physiological parameter, such as: Anaerobic Threshold. As a result of this common mistake, some researchers have debated whether the νο_2pl is a protocol artefact or true physiological phenomenon. However, Taylor, et al. [4] observed that only seven within 115 men had failed to reach νο_2pl . These authors applied a protocol test in which each incremental stage occurred on different days. Moreover, Duncan, et al. [5] investigated the incidence of the νο_2pl during discontinuous versus continuous protocol tests and they concluded that the νο_2pl incidence was equal to 60% of the discontinuous and 50% of the continuous tests. Furthermore, non-published data from our laboratory show a much greater incidence of the νο_2pl on discontinuous tests. The incidence of an oxygen uptake plateau at the νο_2max is associated to the ability of maintaining the maximal effort and postponing the test interruption, which informs us about the exercise tolerance and, consequently, the anaerobic capacity [6,7]. The test interruption occurs when the accumulation of the metabolic wastes is bigger than their elimination. Thus, the discontinuous protocol test will provide enough time to eliminate part of those metabolic wastes, to buffer the internal milieu and to postpone the exhaustion. Likewise, four minutes of passive resting among the stages will be enough to recover completely the myoglobin, [ATP] and [CP] stores.

On the other hand, if the workload is increased continuously without any rest time, then those metabolic wastes produced in one stage will be added to more metabolic wastes produced in the next stage, thereby the exhaustion will have occurred early. The ceiling effect of the circulatory system is needed to show the νο_2pl ; to do that, the test must involve a big muscular mass, which means running on the treadmill with 3 degrees of slope or wearing toe clips on the cycle ergometer. The effort should also be maintained for 3 minutes, because of the circulatory and respiratory delays, which means that the fast oxygen uptake kinetics phase should be completed. Finally, the increments on the workload should be approximately 1 Metabolic Equivalent [8]. Summing up, the discontinuous test is the best one to show the oxygen uptake plateau and, consequently, to point out the maximal oxygen uptake. Yet, the individual variability in body size, cardio-respiratory fitness, muscular strength, etc. may change the νο_2pl occurrence. Thus, more studies about the rest time among the stages, the stage duration time, the νο_2pl cutoff criterion, and the treadmill slope should be done. Even though above rules sound a little bit arbitrary, they are effective.

1. Costill DL (1967) The relationship between selected physiological variables and distance running performance. J Sports Med Phys Fitness 7(2): 61-6.
2. Howley ET, Bassett DR, Welch HG (1995) Criteria for maximal oxygen uptake: review and commentary. Med Sci Sports Exerc 27(9): 1292-301.
3. Bassett DR, Howley ET (2000) Limiting factors for maximum oxygen uptake and determinants of endurance performance. Med Sci Sports Exerc 32(1): 70-84.
4. Taylor HL, Buskirk E, Henschel A (1955) Maximal oxygen intake as an objective measure of cardio-respiratory performance. J Appl Physiol 8(1): 73-80.
5. Duncan GE, Howley ET, Johnson BN (1997) Applicability of VO2max criteria: discontinuous versus continuous protocols. Med Sci Sports Exerc 29(2): 273-278.
6. Duffield R, Edge J, Bishop D, Goodman C (2007) The relationship between the VO₂ slow component, muscle metabolites and performance during very-heavy exhaustive exercise. J Sci Med Sport 10(3): 127-34.
7. Doncaster G, Marwood S, Iga J, Unnithan V (2016) Influence of oxygen uptake kinetics on physical performance in youth soccer. Eur J Appl Physiol 116(9): 1781-1794.
8. Åstrand P O (2003) Textbook of work physiology: physiological bases of exercise. Human Kinetics.