TY - JOUR PY - 2012// TI - Exercise intensity typical of mountain climbing does not exacerbate acute mountain sickness in normobaric hypoxia JO - Journal of applied physiology A1 - Schommer, Kai A1 - Hammer, Moritz A1 - Hotz, Lorenz A1 - Menold, Elmar A1 - Bartsch, Peter A1 - Berger, Marc Moritz SP - 1068 EP - 1074 VL - 113 IS - 7 N2 - 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

LA - en SN - 8750-7587 UR - http://dx.doi.org/10.1152/japplphysiol.00329.2012 ID - ref1 ER -