Abstract
The aim of this study was to evaluate the influence of arterial oxygen saturation (SaO2) on maximal heart rate during maximal exercise under conditions of acute hypoxia compared with normoxia. Forty-six males were divided into three groups depending on their sea level maximal oxygen consumption (V̇O2max): high [GH, V̇O2max=64.2 (3.3) ml.min−1.kg−1], medium [GM, 50.8 (3.9) ml.min−1.kg−1] and low [GL, 41.0 (1.9) ml.min−1.kg−1]. All subjects performed a maximal exercise test in two conditions of inspired oxygen tension (PIO2, (149 mmHg and 70 mmHg). Among the GM group, seven subjects performed five supplementary incremental exercise tests at PIO2 136, 118, 104, 92, and 80 mmHg. Measurements of V̇O2max and SaO2 using an ear-oxymeter were carried out at all levels of PIO2. The decrease in SaO2 and peak heart rate (HRpeak) with PIO2 became significant from 104 and 92 mmHg. SaO2 correlated with the decrease in HRpeak. For PIO2=70 mmHg, the decrease in V̇O2max, SaO2 and HRpeak was, respectively, 44%, 62%, and 17.0 bpm for GH, 38%, 68%, and 14.7 bpm for GM, and 34%, 68%, and 11.8 bpm for GL. During maximal exercise in hypoxia, SaO2 was lower for GH than GM and GL (p<0.01). Among subjects in GH, five presented exercise-induced hypoxemia (EIH) when exercising in normoxia. The EIH group exhibited a greater decrement in HRpeak than the non-EIH group at maximal hypoxic exercise (21.2 bpm vs. 15.0 bpm; p<0.05). When subjects are exposed to acute hypoxia, the lower SaO2, due either to lower PIO2 or to training status, is associated with lower HRpeak.
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Barthelemy JC, Geyssant A, Riffat J, Antoniadis A, Berruyer J, Lacour JR (1990) Accuracy of pulse oximetry during moderate exercise: a comparative study. Scand J Clin Lab Invest 50:533–539
Benoit H, Busso T, Castells J, Denis C, Geyssant A (1995) Influence of hypoxic ventilatory response on arterial O2 saturation during maximal exercise in acute hypoxia. Eur J Appl Physiol 72:101–105
Benoit H, Costes F, Feasson L, Lacour JR, Roche F, Denis C, Geyssant A, Barthelemy JC (1997) Accuracy of pulse oximetry during intense exercise under severe hypoxic conditions. Eur J Appl Physiol 76:260–263
Bogaard HJ, Hopkins SR, Yamaya Y, Niizeki K, Ziegler MG, Wagner PD (2002) Role of the autonomic nervous system in the reduced maximal cardiac output at altitude. J Appl Physiol 93:271–279
Boushel R, Calbet JA, Radegran G, Sondergaard H, Wagner PD, Saltin B (2001) Parasympathetic neural activity accounts for the lowering of exercise heart rate at high altitude. Circulation 104:1785–1791
Boutellier U, Koller EA (1981) Propranolol and the respiratory, circulatory, and ECG responses to high altitude. Eur J Appl Physiol 46:105–119
Cerretelli P (1980) Gas exchange at high altitude. Pulmon Gas Exch II:97–147
Dempsey JA, Hanson PG, Henderson KS (1984) Exercise-induced arterial hypoxaemia in healthy human subjects at sea level. J Physiol (Lond) 355:161–175
Fagraeus L, Karlsson J, Linnarsson D, Saltin B (1973) Oxygen uptake during maximal work at lowered and raised ambient air pressures. Acta Physiol Scand 87:411–421
Ferretti G, Moia C, Thomet JM, Kayser B (1997) The decrease of maximal oxygen consumption during hypoxia in man: a mirror image of the oxygen equilibrium curve. J Physiol (Lond) 498:231–237
Gonzalez NC, Clancy RL, Moue Y, Richalet JP (1998) Increasing maximal heart rate increases maximal O2 uptake in rats acclimatized to simulated altitude. J Appl Physiol 84:164–168
Hughes RL, Clode M, Edwards RH, Goodwin TJ, Jones NL (1968) Effect of inspired O2 on cardiopulmonary and metabolic responses to exercise in man. J Appl Physiol 24:336–347
Lawler J, Powers SK, Thompson D (1988) Linear relationship between VO2max and VO2max decrement during exposure to acute hypoxia. J Appl Physiol 64:1486–1492
Lundby C, Araoz M, van Hall G (2001) Peak heart rate decreases with increasing severity of acute hypoxia. High Alt Med Biol 2: 369-376.
Martin D, O'Kroy J (1993) Effects of acute hypoxia on the VO2 max of trained and untrained subjects. J Sports Sci 11:37–42
Powers SK, Dodd S, Lawler J, Landry G, Kirtley M, McKnight T, Grinton S (1988) Incidence of exercise induced hypoxemia in elite endurance athletes at sea level. Eur J Appl Physiol 58:298–302
Powers SK, Lawler J, Dempsey JA, Dodd S, Landry G (1989) Effects of incomplete pulmonary gas exchange on VO2 max. J Appl Physiol 66:2491–2495
Pugh LGCE (1964) Cardiac output in muscular exercise at 5800 m (19,000ft). J Appl Physiol 19:441–447
Reeves JT, Groves BM, Sutton JR, Wagner PD, Cymerman A, Malconian MK, Rock PB, Young PM, Houston CS (1987) Operation Everest II: preservation of cardiac function at extreme altitude. J Appl Physiol 63:531–539
Richalet JP, Larmignat P, Rathat C, Keromes A, Baud P, Lhoste F (1988) Decreased cardiac response to isoproterenol infusion in acute and chronic hypoxia. J Appl Physiol 65:1957–1961
Roach RC, Calbet JA, Olsen NV, Poulsen TD, Vissing SF, Saltin B (1996) Peak exercise heart rate in humans at high altitude. J Physiol (Lond) 491P:60P–61P
Robergs RA, Quintana R, Parker DL, Frankel CC (1998) Multiple variables explain the variability in the decrement in VO2max during acute hypobaric hypoxia. Med Sci Sports Exerc 30:869–879
Roche F, Reynaud C, Pichot V, Duverney D, Costes F, Gaspoz JM, Barthélémy JC (2003) Effect of acute hypoxia on QT rate dependence and corrected QT interval in healthy subjects. Am J Cardiol (in press)
Saurenmann P, Koller EA (1984) The ECG changes due to altitude and to catecholamines. Eur J Appl Physiol 53:35–42
Savard GK, Areskog NH, Saltin B (1995) Cardiovascular response to exercise in humans following acclimatization to extreme altitude. Acta Physiol Scand 154:499–509
Scholander PF (1947) Analyzer for accurate estimation of respiratory gases in one-half cubic centimeter samples. J Biol Chem 167:235–250
Shephard RJ, Bouhlel E, Vandewalle H, Monod H (1988) Peak oxygen intake and hypoxia: influence of physical fitness. Int J Sports Med 9:279–283
Wagner JA, Miles DS, Horvath SM, Reyburn JA (1979) Maximal work capacity of women during acute hypoxia. J Appl Physiol 47:1223–1227
Wagner PD (2000) Reduced maximal cardiac output at altitude – mechanisms and significance. Respir Physiol 120:1–11
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The authors wish to record their thanks to R. Bonnefoy for technical assistance.
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Benoit, H., Busso, T., Castells, J. et al. Decrease in peak heart rate with acute hypoxia in relation to sea level V̇O2max . Eur J Appl Physiol 90, 514–519 (2003). https://doi.org/10.1007/s00421-003-0899-y
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DOI: https://doi.org/10.1007/s00421-003-0899-y