Novel precooling strategy enhances time trial cycling in the heat.
OBJECTIVE
To develop and investigate the efficacy of a new precooling strategy combining external and internal techniques on the performance of a cycling time trial (TT) in a hot and humid environment.


METHODS
Eleven well-trained male cyclists undertook three trials of a laboratory-based cycling TT simulating the course characteristics of the Beijing Olympic Games event in a controlled hot and humid environment (32°C-35°C at 50%-60% relative humidity). The trials, separated by 3-7 d, were undertaken in a randomized crossover design and consisted of the following: 1) CON-no treatment apart from the ad libitum consumption of cold water (4°C), 2) STD COOL-whole-body immersion in cold (10°C) water for 10 min followed by wearing a cooling jacket, or 3) NEW COOL-combination of consumption of 14 g of ice slurry ("slushie") per kilogram body mass made from a commercial sports drink while applying iced towels.


RESULTS
There was an observable effect on rectal temperature (T(rec)) before the commencement of the TT after both precooling techniques (STD COOL < NEW COOL < CON, P < 0.05), but pacing of the TT resulted in similar T(rec), HR, and RPE throughout the cycling protocol in all trials. NEW COOL was associated with a 3.0% increase in power (approximately 8 W) and a 1.3% improvement in performance time (approximately 1:06 min) compared with the CON trial, with the true likely effects ranging from a trivial to a large benefit. The effect of the STD COOL trial compared with the CON trial was "unclear."


CONCLUSIONS
This new precooling strategy represents a practical and effective technique that could be used by athletes in preparation for endurance events undertaken in hot and humid conditions.
Ross
Megan L R
ML
Australian Institute of Sport, Belconnen, Australian Capital Territory, Australia.
Garvican
Laura A
LA
Jeacocke
Nikki A
NA
Laursen
Paul B
PB
Abbiss
Chris R
CR
Martin
David T
DT
Burke
Louise M
LM
D000293:Adolescent; D000328:Adult; D054874:Athletic Performance / Q000502:physiology*; D001642:Bicycling / Q000502:physiology*; D001831:Body Temperature; D001833:Body Temperature Regulation; D003080:Cold Temperature; D018592:Cross-Over Studies; D004326:Drinking / Q000502:physiology; D006358:Hot Temperature; D006801:Humans; D006813:Humidity; D007053:Ice; D008297:Male; D013995:Time; D055815:Young Adult
D007053:Ice