Home > Riviste > The Journal of Sports Medicine and Physical Fitness > Fascicoli precedenti > The Journal of Sports Medicine and Physical Fitness 2003 September;43(3) > The Journal of Sports Medicine and Physical Fitness 2003 September;43(3):386-92

ULTIMO FASCICOLO
 

ARTICLE TOOLS

Estratti

THE JOURNAL OF SPORTS MEDICINE AND PHYSICAL FITNESS

Rivista di Medicina, Traumatologia e Psicologia dello Sport


Indexed/Abstracted in: Chemical Abstracts, CINAHL, Current Contents/Clinical Medicine, EMBASE, PubMed/MEDLINE, Science Citation Index Expanded (SciSearch), Scopus
Impact Factor 1,215


eTOC

 

Original articles  EPIDEMIOLOGY AND CLINICAL MEDICINE


The Journal of Sports Medicine and Physical Fitness 2003 September;43(3):386-92

Copyright © 2009 EDIZIONI MINERVA MEDICA

lingua: Inglese

Individual differences in self-reported heat tolerance. Is there a link to the cardiocirculatory, thermoregulatory and hormonal response to endurance exercise in heat?

Niess A. M. 1, Feherenbach E. 2, Roecker K. 1, Lehmann R. 3, Opavsky L. 4, Dickhuth H. H. 1

1 Center for Internal Medicine Department of Prevention, Rehabilitation and Sports Medicine Freiburg University Hospital, Germany 2 Department of Transfusion Medicine University of Tuebingen, Tuebingen, Germany 3 Medical Clinic and Polyclinic Department of Endocrinology and Metabolism University of Tuebingen, Tuebingen, Germany 4 Department of Sports Medicine University of Tuebingen, Tuebingen, Germany


PDF  


Aim. Tol­er­ance to exer­cise in ­heat exhib­its ­great inter­in­di­vid­u­al var­i­abil­ity. We ques­tioned wheth­er indi­vid­u­al dif­fer­enc­es in ­self-report­ed ­heat tol­er­ance with­in a ­group of endu­rance ­trained ath­letes are ­linked to the car­di­o­cir­cu­la­to­ry, ther­mo­reg­u­la­to­ry and hor­mo­nal ­response to endu­rance exer­cise in ­heat.
Meth­ods. ­Using a rat­ing ­scale to ­assess the indi­vid­u­al ­degree of tol­er­ance to exer­cise in ­heat we allo­cat­ed 12 non-­heat-accli­mat­ed ­trained run­ners ­into two ­groups of 5 high­ly ­heat tol­er­ant (HHT) and 7 ­less ­heat tol­er­ant (LHT) ath­letes. ­Both ­groups per­formed a 60-min tread­mill run (veloc­ity 90% of indi­vid­u­al anaer­o­bic thresh­old, ­room tem­per­a­ture and humid­ity 28°C and 50%, respec­tive­ly).
­Results. Sweat­ing ­rate did not dif­fer ­between HHT (­mean ± SEM: 0.44±0.02) and LHT (0.40±0.02 ml·kg-1·min-1). Com­pared to LHT, exer­cise-­induced ris­es in ­core tem­per­a­ture (39.3±0.2/40.0±0.2°C), ­heart ­rate, plas­ma nor­epi­neph­rine and cor­ti­sol ­were sig­nif­i­cant­ly low­er in HHT, ­while epi­neph­rine did not exhib­it dif­fer­enc­es ­between the ­groups. In con­trast, ­response of ­human ­growth hor­mone (hGH) was sig­nif­i­cant­ly ­more pro­nounced in HHT.
Con­clu­sion. Our ­initial ­results, ­obtained in a ­small ­group of endu­rance-­trained run­ners, ­show ­that ­self-report­ed tol­er­ance to exer­cise in ­heat is asso­ciat­ed ­with an atten­u­at­ed ­rise in ­body ­core tem­per­a­ture dur­ing pro­longed exer­cise ­under ele­vat­ed ambi­ent tem­per­a­tures. ­This find­ing in ­heat tol­er­ant ath­letes is par­alleled by a low­er ­stress ­response as reflect­ed by low­er ris­es in ­heart ­rate and ­stress hor­mones ­such as nor­epi­neph­rine and cor­ti­sol. The func­tion­al sig­nif­i­cance (i.e. ­with ­respect to sweat­ing func­tion) of the ­more pro­nounced ­response of hGH in ­heat tol­er­ant ath­letes war­rants fur­ther ­research.

inizio pagina

Publication History

Per citare questo articolo

Corresponding author e-mail