Original articles  EXERCISE PHYSIOLOGY AND BIOMECHANICS 

The Journal of Sports Medicine and Physical Fitness 2004 March;44(1):30-7

Copyright © 2009 EDIZIONI MINERVA MEDICA

lingua: Inglese

Effects of 8 days acclimation on biological and performance response in a tropical climate

Hue O. ¹, Voltaire B. ¹, Galy O. ¹, Costes O. ², Callis A. ³, Hertogh C. ¹, Blonc S. ¹

¹ ACTE Laboratory, UFR-STAPS of Antilles and of Guyane, Campus de Fouillole Point à Pitre, France (FWI) 2 Laboratory of Physiology of Interactions CHU Arnaud de Villeneuve, Montpellier, France 3 Laboratory of Biochemistry B CHU Guy de Chauliac, Montpellier, France

Back­ground. ­This ­study was ­designed to deter­mine the accli­ma­tion pro­cess elic­ited by expo­sure to a trop­ical cli­mate.
­Methods. ­Nine tri­ath­letes per­formed 3 out­door indi­rect con­tin­uous run­ning mul­ti­stage ­tests in ­both ther­mo­neu­tral and trop­ical con­di­tions. ­Before trav­el­ling to the trop­ical ­area (Mar­ti­nique ­Island, FWI), the tri­ath­letes per­formed the ther­mo­neu­tral ­test (TN) in 14°C and 45% rh con­di­tions. The trop­ical ­tests ­were per­formed 2 and 8 ­days ­after ­arrival (T2 and T8, per­formed at a ­mean envi­ron­mental tem­per­a­ture of 33.4°C and 75.5% rh). The day ­before T8, ­blood sam­ples ­were ­drawn for bio­chem­ical anal­ysis. ­During ­each ­test, tym­panic tem­per­a­ture, ­sweat ­rate, ­weight ­loss, ­heart ­rate (HR), and per­for­mance ­were ­recorded.
­Results. The ­results dem­on­strated ­that: 1) the ­mean tym­panic tem­per­a­ture was ­greater in T2 (p<0.001) and T8 (p<0.01) ­than in TN; 2) the ­mean ­sweat ­rate was sig­nif­i­cantly ­greater (p<0.001) in T2 and T8 ­than in TN and sig­nif­i­cantly ­greater in T8 ­than in T2 (p<0.03); 3) the ­weight ­loss ­after ­trials was sig­nif­i­cantly ­greater (p<0.001) in T2 and T8 ­than in TN and in T8 ­than in T2 (p<0.04); 4) the ­mean HR and the HR at ­rest ­were sig­nif­i­cantly ­greater in T2 ­than in TN (p<0.001) and T8 (p<0.005); 6) sig­nif­i­cant reduc­tions ­were ­observed in T8 vs TN in red ­cell ­count (p<0.05) and ­plasma pro­teins (p<0.04), the con­se­quence of a 7.5% ­plasma ­volume expan­sion; and 7) the per­for­mance was sig­nif­i­cantly ­lower in ­both T2 (p<0.02) and T8 (p<0.03) ­than in TN.
Con­clu­sions. We con­cluded ­that 8 ­days expo­sure to hot/wet con­di­tions ­induced impair­ments in phys­io­log­ical ­responses and per­for­mance ­that ­were ­still evi­dent on the 8th day. Fur­ther and ­longer out­door ­studies are ­needed to inves­ti­gate if ­return to ­optimal per­for­mance ­levels ­after adap­ta­tion to hot/wet con­di­tions is pos­sible.