High-altitude Tibetans undergo a pattern of adaptations to chronic hypoxia characterized, among others, by a more efficient aerobic performance compared with acclimatized lowlanders. To test whether such changes may persist upon descent to moderate altitude, oxygen uptake of 17 male Tibetan natives lifelong residents at 3500-4500 m was assessed within 1 month upon migration to 1300 m. Exercise protocols were: 5 min treadmill walking at 6 km h-1 on increasing inclines from +5 to +15% and 5 min running at 10 km h-1 on a +5% grade. The data (mean (plus or minus) S.E.M.) were compared with those obtained on Nepali lowlanders. When walking on +10, +12.5 and +15% inclines, net VO2 of Tibetans was 25.2 (plus or minus) 0.7, 29.1 (plus or minus) 1.1 and 31.3 (plus or minus) 0.9 ml kg-1 min-1, respectively, i.e. 8, 10 and 13% less (P < 0.05) than that of Nepali. At the end of the heaviest load, blood lactate concentration was lower in Tibetans than in Nepali (6.0 (plus or minus) 0.9 versus 8.9 (plus or minus) 0.6 mM; P < 0.05). During running, VO2 of Tibetans was 35.1 (plus or minus) 0.8 versus 39.3 (plus or minus) 0.7 ml kg-1 min-1 (i.e. 11% less; P < 0.01). In conclusion, during submaximal walking and running at 1300 m, Tibetans are still characterized by lower aerobic energy expenditure than control subjects that is not accounted for by differences in mechanical power output and/or compensated for by anaerobic glycolysis. These findings indicate that chronic hypoxia induces metabolic adaptations whose underlying mechanisms still need to be elucidated, that persist for at least 1 month upon descent to moderate altitude.

Economy of locomotion in high-altitude Tibetan migrants exposed to normoxia / Claudio Marconi, Mauro Marzorati, Daniele Sciuto, Alessandra Ferri, Paolo Cerretelli. - In: THE JOURNAL OF PHYSIOLOGY. - ISSN 0022-3751. - 569:2(2005 Dec 01), pp. 667-675.

Economy of locomotion in high-altitude Tibetan migrants exposed to normoxia

Alessandra Ferri;Paolo Cerretelli
2005-12-01

Abstract

High-altitude Tibetans undergo a pattern of adaptations to chronic hypoxia characterized, among others, by a more efficient aerobic performance compared with acclimatized lowlanders. To test whether such changes may persist upon descent to moderate altitude, oxygen uptake of 17 male Tibetan natives lifelong residents at 3500-4500 m was assessed within 1 month upon migration to 1300 m. Exercise protocols were: 5 min treadmill walking at 6 km h-1 on increasing inclines from +5 to +15% and 5 min running at 10 km h-1 on a +5% grade. The data (mean (plus or minus) S.E.M.) were compared with those obtained on Nepali lowlanders. When walking on +10, +12.5 and +15% inclines, net VO2 of Tibetans was 25.2 (plus or minus) 0.7, 29.1 (plus or minus) 1.1 and 31.3 (plus or minus) 0.9 ml kg-1 min-1, respectively, i.e. 8, 10 and 13% less (P < 0.05) than that of Nepali. At the end of the heaviest load, blood lactate concentration was lower in Tibetans than in Nepali (6.0 (plus or minus) 0.9 versus 8.9 (plus or minus) 0.6 mM; P < 0.05). During running, VO2 of Tibetans was 35.1 (plus or minus) 0.8 versus 39.3 (plus or minus) 0.7 ml kg-1 min-1 (i.e. 11% less; P < 0.01). In conclusion, during submaximal walking and running at 1300 m, Tibetans are still characterized by lower aerobic energy expenditure than control subjects that is not accounted for by differences in mechanical power output and/or compensated for by anaerobic glycolysis. These findings indicate that chronic hypoxia induces metabolic adaptations whose underlying mechanisms still need to be elucidated, that persist for at least 1 month upon descent to moderate altitude.
China ; Nepal ; adult ; aerobic metabolism ; altitude acclimatization ; altitude ; anaerobic metabolism ; article ; controlled study ; data analysis ; energy expenditure ; environmental exposure ; glycolysis ; human experiment ; human ; hypoxia ; lactate blood level ; loading test ; locomotion ; male ; migration ; native species ; oxygen consumption ; priority journal ; running ; statistical analysis ; treadmill exercise ; walking ; lactic acid ; oxygen
Settore BIO/09 - Fisiologia
THE JOURNAL OF PHYSIOLOGY
http://jp.physoc.org/cgi/content/full/569/2/667
Article (author)
File in questo prodotto:
Non ci sono file associati a questo prodotto.
Pubblicazioni consigliate

Caricamento pubblicazioni consigliate

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/2434/25361
Citazioni
  • ???jsp.display-item.citation.pmc??? 7
  • Scopus 34
  • ???jsp.display-item.citation.isi??? 32
social impact