Preliminary results of VO2max and arterial O2 saturation at sea level versus 610m

Gore, C.J., Hahn, A.G., Watson, D.B., Norton, K.I., Campbell, D.P., Scroop, G.S., Emonson, D. L. Wood, R.J., Ly, S. Bellenger, S., Lawton, E., 'VO2max and arterial O2 saturation at sea level & 610 m', Proceedings of the American College of Sports Medicine Annual Conference, Medicine and Science in Sport and Exercise, Supplement to Vol 27(5), pS7, May 1995.

The aim of this study was to test the hypothesis that the VO2max of elite athletes, but not non-elite athletes, is decreased at sea level compared with 610 m (Canberra's altitude) as a result of lower arterial oxygen saturation (%SaO2). Twenty men each completed 2 cycle ergometer VO2max, tests within 2 - 3 days. The men were divided into 2 groups, Elite (n = 11, mean ± se; VO2max = 77 ± 1 ml.kg-1) and Non-elite (n = 9, VO2max = 51 ± 3 ml.kg-1.min-1). Tests were conducted in an hypobaric chamber using a double-blind, counter-balanced design. Chamber conditions were equal to the lowest barometric pressure that might occur at sea level (745 mm Hg) and at Canberra (695 mm Hg). Arterial blood was taken at rest, exercise minute 7 and VO2max. There was a significant interaction for VO2max between the athlete group and chamber pressure (F1.18) = 5.25). The VO2max of the non-elite group did not change significantly from 3.93 ± 0.18 L.min'1 at 745 mmHg to 3.79 ± 0.16 l.min-1 at 695 mm Hg, while that of the elite group decreased significantly from 5.48 ± 0.09 L.min'1 at 745 mmHg to 5.10 ± 0.08 L.min'1 at 695 mmHg. The interaction for %Sa02 between the time, athlete group and chamber pressure was a significant (F2.26 = 7.41). At rest, the %Sa02 was not different between the groups at either 745 or 695 mm Hg, ranging from 96.5 to 97.7%. At VO2max the %Sa02 of the non-elite group did not change between 745 mm Hg (94.7 %) and 695 mm Hg (93.7 %), while that of the elite group fell significantly from 90.4 % at 745 mm Hg to 86.5% at 695 mm Hg. A compromised VO2max at only 610 m is a lower altitude than previously reported.

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