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Titolo:
The influence of whole-body vs. torso pre-cooling on physiological strain and performance of high-intensity exercise in the heat
Autore:
Sleivert, GG; Cotter, JD; Roberts, WS; Febbraio, MA;
Indirizzi:
Univ Otago, Sch Phys Educ, Dunedin, New Zealand Univ Otago Dunedin New Zealand ago, Sch Phys Educ, Dunedin, New Zealand DSTO, Combatant Protect & Nutr Branch, Melbourne, Vic, Australia DSTO Melbourne Vic Australia ct & Nutr Branch, Melbourne, Vic, Australia Univ Melbourne, Dept Physiol, Melbourne, Vic, Australia Univ Melbourne Melbourne Vic Australia hysiol, Melbourne, Vic, Australia
Titolo Testata:
COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY A-MOLECULAR AND INTEGRATIVE PHYSIOLOGY
fascicolo: 4, volume: 128, anno: 2001,
pagine: 657 - 666
SICI:
1095-6433(200104)128:4<657:TIOWVT>2.0.ZU;2-U
Fonte:
ISI
Lingua:
ENG
Soggetto:
SKINNED MUSCLE-FIBERS; POWER OUTPUT; TEMPERATURE; RESPONSES; MECHANICS; FATIGUE; STRESS; HUMANS; PH;
Keywords:
anaerobic; thermoregulation; cycling; power; oxygen deficit; pre-cool; heat; cold; warm-up; muscle temperature; fatigue;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Agriculture,Biology & Environmental Sciences
Life Sciences
Citazioni:
35
Recensione:
Indirizzi per estratti:
Indirizzo: Sleivert, GG Univ New Brunswick, Fac Kinesiol, POB 4400, Fredericton, NB E3B 5A3, Canada Univ New Brunswick POB 4400 Fredericton NB Canada E3B 5A3 ada
Citazione:
G.G. Sleivert et al., "The influence of whole-body vs. torso pre-cooling on physiological strain and performance of high-intensity exercise in the heat", COMP BIOC A, 128(4), 2001, pp. 657-666

Abstract

Little research has been reported examining the effects of pre-cooling on high-intensity exercise performance, particularly when combined with strategies to keep the working muscle warm. This study used nine active males to determine the effects of pre-cooling the torso and thighs (LC), pre-coolingthe torso lice-vest in 3 degreesC air) while keeping the thighs warm (LW),or no cooling (CON: 31 degreesC air), on physiological strain and high-intensity (45-s) exercise performance (33 degreesC, 60% rh). Furthermore, we sought to determine whether performance after pre-cooling was influenced by a short exercise warm-up. The 45-s test was performed at different (P < 0.05) mean core temperature [(rectal + oesophageal)/2] [CON: 37.3 +/- 0.3 (S.D.), LW: 37.1 +/- 0.3, LC: 36.5 +/- 0.4<degrees>C] and mean skin temperature(CON: 34.6 +/- 0.0, LW: 29.0 +/- 1.0, LC: 27.2 +/- 1.2 degreesC) between all conditions. Forearm blood flow prior to exercise was also lower in LC (3.1 +/- 2.0 ml 100 mi tissue(-1) min(-1)) than CON (8.2 +/- 2.5, P = 0.01) but not LW (4.3 +/- 2.6, P = 0.46). After an exercise warm-up, muscle temperature (T-m) was not significantly different between conditions (CON: 37.3 +/- 1.5, LW: 37.3 +/- 1.2, LC: 36.6 +/- 0.7 degreesC, P = 0.16) but. when warm-up was excluded, T-m was lower in LC (34.5 +/- 1.9 degreesC, P = 0.02) than in CON (37.3 +/- 1.0) and LW (37.1 +/- 0.9) Even when a warm-up was performed, torso + thigh pre-cooling decreased both peak (-3.4+/-3.8%, P = 0.04) and mean power output (-4.1 +/- 3.8%, P = 0.01) relative to the control,but this effect was markedly larger when warm-up was excluded (peak power -7.7 +/- 2.5%, P = 0.01; mean power -7.6 +/- 1.2%, P = 0.01). Torso-only pre-cooling did not reduce peak or mean power, either with or without warm-up. These data indicate that pre-cooling does not improve 45-s high-intensityexercise performance, and can impair performance if the working muscles are cooled. A short exercise warm-up largely removes any detrimental effects of a cold muscle on performance by increasing T-m. (C) 2001 Elsevier Science Inc. All rights reserved.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 19/01/20 alle ore 08:54:17