TY  - JOUR
AU  - Daanen, H.A.
A2  - Daanen, H.A.
A2  - Es, E.M. van
A2  - Graaf, J.L. de
DB  - BISp
DP  - BISp
KW  - Ausdauerbelastung
KW  - Belastungstest
KW  - Hitzebelastung
KW  - Hitzekollaps
KW  - Hyperthermie
KW  - Kälteanwendung
KW  - Körper
KW  - Körpertemperatur
KW  - Kühlung
KW  - Leistungsfähigkeit, körperliche
KW  - Oberkörper
KW  - Radsport
KW  - Sportmedizin
KW  - Thermoregulation
KW  - Unterkörper
KW  - Untersuchung, vergleichende
LA  - eng
TI  - Heat strain and gross efficiency during endurance exercise after lower, upper, or whole body precooling in the heat
TT  - Hitzebelastung und Gesamtwirkungsgrad während Ausdauerbelastung nach Unterkörper-, Oberkörper- oder Ganzkörpervorkühlung bei Hitze
PY  - 2006
N2  - The maximal power that muscles can generate is reduced at low muscle temperatures. However, in prolonged heavy exercise in the heat, a high core temperature may be the factor limiting performance. Precooling has been shown to delay the attainment of hyperthermia. It is still unclear if the whole body should be cooled or if the active muscles should be excluded from cooling in order to maintain muscle power. An experiment was performed to compare thermal strain and gross efficiency following whole body or partial body cooling. Eight well-trained participants performed 40 min of 60% VO2max cycling exercise in a 30 degrees C, 70% relative humidity climatic chamber after four different precooling sessions in a water perfused suit: N (no precooling), CC (45 min whole body precooling), WC (45 min lower body precooling), and CW (45 min upper body precooling). The uncooled body part was warmed in such a way that the core temperature did not differ from that in session N. Gross efficiency was used to compare performance between the sessions since it indicates how much oxygen is needed for a certain external load. The gross efficiency did not differ significantly between the sessions. Differences in heat loss and heat storage were observed during the first 20 min of exercise. The evaporative heat loss in session WC (305 +/- 67 W) and CW (284 +/- 68 W) differed from session N (398 +/- 77 W) and CC (209 +/- 58 W). More heat was stored in session CC (442 +/- 125 W) than in sessions WC (316 +/- 39 W), CW (307 +/- 63 W), and N (221 +/- 65 W). It was confirmed that precooling reduces heat strain during exercise in the heat. No differences in heat strain and gross efficiency were observed between precooling of the body part with the exercising muscles and precooling of the tissues elsewhere in the body.   Verf.-Referat
L2  - https://dx.doi.org/10.1055/s-2005-865746
DO  - 10.1055/s-2005-865746
SP  - S. 379-388
SN  - 0172-4622
JO  - International journal of sports medicine
IS  - 5
VL  - 27
M3  - Gedruckte Ressource
M3  - Elektronische Ressource (online)
ID  - PU200702000358
ER  -