3
ISSUL, University of Lausanne, Institute of Sport Sciences and Physical Education (ISSEP), Lausanne, Switzerland
,
João Viana
4
Research Center in Sports Sciences, Health Sciences and Human Development, CIDESD, University Institute of Maia, ISMAI, Maia, Portugal
,
Jaime Milheiro
5
Portuguese Olympic Committee, COP, Portugal
,
Vítor Reis
6
CMEP – Exercise Medical Center, Porto, Portugal
› InstitutsangabenFunding: This work received funding from the Portuguese Foundation for Science and Technology, I.P. (SFRH/BPD/114670/2) and under the project UID04045/2020.
We investigated the effects of hypoxia on matched-severe intensity exercise and on the parameters of the power-duration relationship. Fifteen trained subjects performed in both normoxia and normobaric hypoxia (FiO2=0.13, ~3000 m) a maximal incremental test, a 3 min all-out test (3AOT) and a transition from rest to an exercise performed to exhaustion (Tlim) at the same relative intensity (80%∆). Respiratory and pulmonary gas-exchange variables were continuously measured (K5, Cosmed, Italy). Tlim test’s V̇O2 kinetics was calculated using a two-component exponential model. V̇O2max (44.1±5.1 vs. 58.7±6.4 ml.kg-1.min-1, p<0.001) was decreased in hypoxia. In Tlim, time-to-exhaustion sustained was similar (454±130 vs. 484±169 s) despite that V̇O2 kinetics was slower (τ1: 31.1±5.8 vs. 21.6±4.7 s, p<0.001) and the amplitude of the V̇O2 slow component lower (12.4±5.4 vs. 20.2±5.7 ml.kg-1.min-1, p<0.05) in hypoxia. CP was reduced (225±35 vs. 270±49 W, p<0.001) but W’ was unchanged (11.3±2.9 vs. 11.4±2.7 kJ) in hypoxia. The changes in CP/V̇O2max were positively correlated with changes in W’ (r = 0.58, p<0.05). The lower oxygen availability had an impact on aerobic related physiological parameters, but exercise tolerance is similar between hypoxia and normoxia when the relative intensity is matched despite a slower V̇O2 kinetics in hypoxia.
Key words
exercise-to-exhaustion -
critical power -
hypoxia -
W'
4
Deb SK,
Brown DR,
Gough LA.
et al. Quantifying the effects of acute hypoxic exposure on exercise performance and capacity: A systematic review and meta-regression. Eur J Sport Sci 2018; 18: 243-256
5
Heubert R,
Quaresima V,
Laffite L.
et al. Acute moderate hypoxia affects the oxygen desaturation and the performance but not the oxygen uptake response. Int J Sports Med 2005; 26: 542-551
6
Billat V,
Lepretre P,
Heubert R.
et al. Influence of acute moderate hypoxia on time to exhaustion at V˙O2max in unacclimatized runners. Int J Sports Med 2003; 24: 9-14
7
Engelen M,
Porszasz J,
Riley M.
et al. Effects of hypoxic hypoxia on O2 uptake and heart rate kinetics during heavy exercise. J Appl Physiol (1985) 1996; 81: 2500-2508
8
Kelly J,
Vanhatalo A,
Bailey SJ.
et al. Dietary nitrate supplementation: effects on plasma nitrite and pulmonary O2 uptake dynamics during exercise in hypoxia and normoxia. Am J Physiol Regul Integr Comp Physiol 2014; 307: R920-R930
9
Black MI,
Potter CR,
Corbett J.
et al. Maximal oxygen uptake is achieved in hypoxia but not normoxia during an exhaustive severe intensity run. Front Physiol 2017; 8: 96
10
Poole DC,
Burnley M,
Vanhatalo A.
et al. Critical power: An important fatigue threshold in exercise physiology. Med Sci Sports Exerc 2016; 48: 2320-2334
12
Moritani T,
Nagata A,
Devries HA.
et al. Critical power as a measure of physical work capacity and anaerobic threshold. Ergonomics 1981; 24: 339-350
13
Simpson LP,
Jones A,
Skiba P.
et al. Influence of hypoxia on the power-duration relationship during high-intensity exercise. Int J Sports Med 2015; 36: 113-119
15
Shearman S,
Dwyer D,
Skiba P.
et al. Modeling intermittent cycling performance in hypoxia using the critical power concept. Med Sci Sports Exerc 2016; 48: 527-535
16
La Monica MB,
Fukuda DH,
Starling-Smith TM.
et al. Effects of normobaric hypoxia on upper body critical power and anaerobic working capacity. Respir Physiol Neurobiol 2018; 249: 1-6
17
Murgatroyd SR,
Ferguson C,
Ward SA.
et al. Pulmonary O2 uptake kinetics as a determinant of high-intensity exercise tolerance in humans. J Appl Physiol (1985) 2011; 110: 1598-1606
18
Vanhatalo A,
Poole DC,
DiMenna FJ.
et al. Muscle fiber recruitment and the slow component of O2 uptake: Constant work rate vs. all-out sprint exercise. Am J Physiol Regul Integr Comp Physiol 2011; 300: R700-R707
22
Kuipers H,
Verstappen F,
Keizer H.
et al. Variability of aerobic performance in the laboratory and its physiologic correlates. Int J Sports Med 1985; 6: 197-201
23
Binder RK,
Wonisch M,
Corra U.
et al. Methodological approach to the first and second lactate threshold in incremental cardiopulmonary exercise testing. Eur J Cardiovasc Prev Rehabil 2008; 15: 726-734
25
Jones AM,
DiMenna F,
Lothian F.
et al. 'Priming' exercise and O2 uptake kinetics during treadmill running. Respir Physiol Neurobiol 2008; 161: 182-188
27
Ofner M,
Wonisch M,
Frei M.
et al. Influence of acute normobaric hypoxia on physiological variables and lactate turn point determination in trained men. J Sports Sci Med 2014; 13: 774
29
Wehrlin J,
Hallén J..
Linear decrease in VO2max and performance with increasing altitude in endurance athletes. Eur J Appl Physiol 2006; 96: 404-412
30
Amann M,
Romer LM,
Subudhi AW.
et al. Severity of arterial hypoxaemia affects the relative contributions of peripheral muscle fatigue to exercise performance in healthy humans. J Physiol 2007; 581: 389-403
34
Townsend NE,
Nichols DS,
Skiba PF.
et al. Prediction of critical power and w′ in hypoxia: Application to work-balance modelling. Front Physiol 2017; 8: 180
35
Ferguson C,
Rossiter HB,
Whipp BJ.
et al. Effect of recovery duration from prior exhaustive exercise on the parameters of the power-duration relationship. J Appl Physiol (1985) 2010; 108: 866-874
