ISSN:
1432-1254
Keywords:
High altitude
;
Acclimatization
;
Metabolic changes
Source:
Springer Online Journal Archives 1860-2000
Topics:
Geography
,
Physics
Notes:
Abstract The study was carried out on 16 men (aged 20–30 years) to evaluate daily metabolic responses during the early phase of altitude acclimatization at moderate altitudes between 3100 and 4200 m in the Eastern Himalayas. Resting (R) and submaximal exercise (E) oxygen consumption (|VO2) at 100 W at sea level (SL) were 3.25 (SEM 0.15) and 20.31 (SEM 0.77) ml/kg per min respectively. On day 1 at 3110 m both R and E |VO2 decreased (P〈0.001) and subsequently remained constant. At 3445 m these values tended to increase over the 3110 m values but were lower than the SL values. At 4177 m the decline in |VO2 was significantly greater (P〈0.01) than at the preceding altitudes. Pulmonary ventilation (|VE) increased consistently (P〈0.001) with increase in altitude. The arterial oxygen saturation (S a O2) at different altitudes was lower (P〈0.001) than SL values. The cardiac frequency (f C ) at R and E was higher (P〈0.001) at altitude; the values at 3110 and 3445 m were significantly lower (P〈0.001) than at 4177 m. Blood pressure (BP) increased (P〈0.001) on the first day at each altitude. The systolic BP tended to decline towards SL values but the diastolic BP remained high (P〈0.001) throughout. The resting blood lactic acid concentration, [la −] bl , showed a decline (P〈0.001) only at 4177 m. The [la −] bl at E was similar at 3110 and 3445 m but was higher (P〈0.01) at 4177 m. These observations suggest that acclimatization to a mid-altitude of 3445 m can be safely avoided where rapid ascent to higher altitude is required.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01211225
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