Exercise responses after altitude acclimatization are retained during reintroduction to altitude.

摘要: Following 2 to 3 wk of altitude acclimatization, ventilation is increased and heart rate (HR), plasma volume (PV), lactate accumulation ([La]) are decreased during submaximal exercise. The objective this study was determine whether some degree these exercise responses associated with acclimatization would be retained upon reintroduction (RA) after 8 d at sea level (SL). Six male lowlanders (X +/- SE; 31 yr, 82.4 4.6 kg) exercised exhaustion the same relative percentages peak oxygen uptake (VO2peak) SL, on acute (AA) exposure, a 16-d chronic (CA) exposure Pikes Peak (4,300 m), 3- 4-h RA in hypobaric chamber m; 446 mm Hg) SL. time (min) SL (66.0 1.6), AA (67.7 7.3), CA (79.9 6.2), (67.9 1.9). At 75% VO2peak: (1) arterial saturation (SaO2) from (67.0 1.5 vs 78.5 1.8%; P < 0.05) remained (77.0 2.0%); (2) HR (171 6 152 9 beats x min-1; (157 5 min-1); (3) calculated PV 6.9 10.0% AA, 21.3 11.1% CA, 16.7 5.4% baseline values, (4) [La] (5.1 0.9 1.9 0.4 mmol L-1; (2.6 0.6 L-1). Upon were 92 9% for SaO2, 74 8% PV, 58 3% VO2peak. In conclusion, although not improved level, retention beneficial likely individuals whose work, athletic competition, or recreation schedules involve intermittent sojourns high elevations.