Delayed acclimatization of the ventilatory threshold in healthy trekkers.
OBJECTIVE
To test the hypothesis that acclimatization to high altitude results in an improvement of the ventilatory threshold (VT).


METHODS
Eight lowlanders underwent cardiopulmonary exercise testing with a cycle ergometer to determine VT and peak oxygen uptake (Vo2peak) in Coventry, United Kingdom (altitude: 80 m), on arrival in leh, india (altitude: 3500 m), and after 12 days of acclimatization that included a 5-day high altitude trek up to 4770 m.


RESULTS
Vo2peak fell on arrival at 3500 m and remained depressed at 12 days. VT was depressed on arrival at high altitude and was further depressed at 12 days. VT as a proportion of the Vo2peak was decreased on arrival at high altitude, and after acclimatization, this relationship was further decreased.


CONCLUSIONS
Individuals who are sedentary or not participating in regular physical training appear to require a longer period of acclimatization than trained athletes. With the increasing numbers participating in high-altitude trekking and charity climbs of peaks, such as Mt. Kilimanjaro, this information has clinically significant practical implications for those leading or acting as medical advisors.
Myers
Stephen D
SD
School of Sport, Exercise and Health Sciences, University of Chichester, College Lane, Chichester, West Sussex, United Kingdom.
Biccard
Bruce M
BM
Chan
Colin
C
Imray
Christopher H E
CH
Wright
Alexander D
AD
Pattinson
Kyle T S
KT
D000064:Acclimatization / Q000502:physiology*; D000328:Adult; D000531:Altitude; D000532:Altitude Sickness / Q000453:epidemiology* / Q000517:prevention & control; D005080:Exercise Test; D005260:Female; D006801:Humans; D000860:Hypoxia / Q000503:physiopathology; D008297:Male; D008451:Maximal Voluntary Ventilation / Q000502:physiology*; D010101:Oxygen Consumption / Q000502:physiology*