The physiological effects of pre-event and midevent cooling during intermittent running in the heat in elite female soccer players

Abstract

The purpose of this study was to examine the effects of both pre-exercise and combined pre-exercise and midexercise cooling strategies during simulated match play in elite female soccer players in the heat. Eight elite female soccer players performed two 45 min periods of intermittent running separated by 15 min seated rest on 3 separate occasions (30.6 +/- 0.2 degrees C, 63.4 +/- 2.5% relative humidity). Participants undertook a no-cooling (CON) or ice-vest cooling for 20 min pre-exercise (PRE) or both pre-exercise and during the 15 min rest period (PRE+MID). Rectal temperature (Tre), skin temperatures, and heart rate were monitored continuously. Mean skin temperature (TMS) and heat storage were calculated. Significant interactions (trial x time) were observed for the change in Tre from rest, TMS, and heat storage (p < 0.05). The change in Tre from rest was greater during CON when compared with PRE and PRE+MID from 35 min until the end of exercise (p < 0.05). When compared with CON (p < 0.05), TMS was lower after precooling (PRE and PRE+MID) and during the 15 min rest period and the first 5 min of the second exercise bout for PRE+MID. Heat storage was also lower after precooling (PRE and PRE+MID) (p < 0.05) and from 60 min until the end of exercise for PRE+MID (p < 0.05) and until 85 min and again at 95 min during PRE (p < 0.05). The results of this study suggest that both cooling strategies were effective in reducing thermal strain during intermittent exercise in the heat. However, PRE+MID cooling was more effective than PRE cooling in offsetting heat storage.

Practical Torso Cooling During Soccer-Specific Exercise in the Heat

“…13 A performance benefit may have been observed if participants had worn an uncooled vest rather than no vest during the no-vest trial; however, such a comparison would likely overstate any true benefit because wearing uncooled garments is not normal practice and can impair performance when compared with cooled equivalents due to discomfort and a lack of physiological and perceptual benefits. 31 Previous data 6,9,15 have suggested that an inverse relationship exists between core body temperature and intermittent-sprint ability; however, in our study, PSS was greatest in the 90th minute of the intermittentsprint protocol during both trials, when core temperatures were at their highest (Figures 1 and 2). It is not uncommon for participants to spurt at the end of self-paced activities when they know that no further efforts will be required.…”

“…Precooling using cooling vests can lower core body and skin temperatures, reduce heart rate (HR), and improve the perceptions of task difficulty and thermal comfort. [13][14][15][16] However, not all vests offer a sufficiently prolonged cooling effect to induce such changes, 16,17 so cooling strategies applied during exercise may be an option to consider. Cooling vests worn during exercise (percooling) can improve exercise capacity during heat stress [18][19][20] ; yet they may effectively reduce physiological strain only when the magnitude of heat stress is very high (eg, when an individual is encapsulated in a nuclear, biological, chemical suit).…”

Hitze, Kälte und Höhenexposition im Fußball: Adaptive Mechanismen und Verhaltensstrategien in variierenden Umweltbedingungen

“…B. Kühlwesten, Eispackungen, Kaltwasserbäder oder kühlen Getränken). Die 20 minütige Applikation von Kühlwesten vor einem Spiel bei 30,6 ± 0,2°C, als auch für 10 Minuten während der Halbzeitpause führte zu einer verringerte Körperkerntemperatur (1,1 ± 0,6 vs. 0,7 ± 0,3°C; p < 0,05) bei professionellen Fußballspielerinnen [27]. Obwohl im Fußball nicht erforscht und dennoch von hoher praktischer Relevanz, führen sogenannte "Ice-slushs" (Getränke die während des Gefriervorganges durch kontinuierliches Umrühren nur zum Teil kristallisiert und nicht gänzlich erhärtet) zu signifikanter Reduktion der Körperkerntemperatur bei intensiver körperlicher Belastung und 34°C (60 % relative Luftfeuchtigkeit) [28].…”

Internal and external cooling methods and their effect on body temperature, thermal perception and dexterity

“…cold water, ice vest) to an individual’s skin. The cooled skin may subsequently cool the cutaneous circulating blood and abate the rise in deep body temperature during work [ 9 , 10 ]. Internal cooling involves an individual ingesting (e.g.…”