Citation

Schommer K, Hammer M, Hotz L, Menold E, Bartsch P, Berger MM. J. Appl. Physiol. (APS Bethesda) 2012; 113(7): 1068-1074.

Affiliation

University Hospital Heidelberg.

Copyright

(Copyright © 2012, American Physiological Society)

DOI

10.1152/japplphysiol.00329.2012

PMID

22858630

Abstract

Physical exertion is thought to exacerbate acute mountain sickness (AMS). In this prospective, randomized, cross-over trial we investigated whether moderate exercise worsens AMS in normobaric hypoxia (12% oxygen, equivalent to 4500 m). Sixteen subjects were exposed to altitude twice, once with exercise (3x45 min within the first 4 hours on a bicycle ergometer at 50% of their altitude-specific maximal workload (VO(2)max)), once without. AMS was evaluated by the Lake Louise score (LLS) and the AMS-C score of the Environmental Symptom Questionnaire. There was no significant difference in AMS between the exposures with and without exercise neither after 5, 8 nor 18 hours (Incidence: 64% and 43%; LLS: 6.5±0.7 and 5.1±0.8; AMS-C score: 1.2±0.3 and 1.1±0.3 for exercise versus rest at 18 hours; all P>0.05). Exercise decreased capillary PO(2) (from 36±1 mmHg at rest to 31±1 mmHg), capillary SaO(2) (from 72% at rest to 67±2%) and cerebral oxygen saturation (from 49±2% at rest to 42±1% as assessed by near infrared spectroscopy; P<0.05), and increased ventilation (capillary PCO(2) 27±1 mmHg; P<0.05). After exercise the increase in ventilation persisted for several hours and was associated with similar levels of capillary and cerebral oxygenation at the exercise and rest day. We conclude that moderate exercise at about 50% VO(2)max does not increase AMS in normobaric hypoxia. These data do not exclude that considerably higher exercise intensities exacerbate AMS.

Language: en