A COLD NECK-COLLAR IMPROVES PERFORMANCE IN THE HEAT
Tyler, C. J., & Sunderland, C. D. (2009). Neck cooling enhances running capacity and thermal tolerance during exercise in hot conditions. ACSM 56th Annual Meeting, Seattle, Washington, Presentation Number 2673.
This study investigated the effects of cooling the neck region on treadmill running capacity in the heat. Well-trained males (N = 7) completed four runs to exhaustion at 70% VO2max in the heat (32°C; 52% RH) following an 8-minute warm-up. All trials were separated by seven days. The first two trials (F1 and F2) were without a collar for all Ss. A cold collar was worn for one of the remaining two trials. Rectal temperature, neck temperature, heart rate, rating of perceived exertion, and thermal sensation (whole-body and neck) were measured every five minutes and at the point of exhaustion in the final two (non-collar and collar) trials. Time to exhaustion was recorded for all trials. The reliability of the test to exhaustion was assessed via the coefficient of variation between F1 and F2 and between F2 and the non-collar trials. The distances covered and the variables recorded at the termination of exercise in the collar and non-collar trials were compared.
The coefficients of variation between F1 and F2 and between F2 and the non-collar trial were 9.2% and 7.8% respectively. Ss ran longer wearing the cold collar than in the non-collar condition. All Ss ran for longer when wearing the cold collar improving over the non-collar condition by 11.3 - 22.4%. Despite no significant differences at the beginning of the two experimental trials, Ss terminated the cold-collar trial at a higher heart rate with no differences in core temperature, rating of perceived exertion, or whole body thermal sensation. Neck temperature and neck thermal comfort were both significantly lower in cold-collar condition.
Implication. Cooling the neck improves exercise capacity in the heat. [Cooling the neck could provide a false signal of the body’s thermal state allowing for a greater strain to be tolerated before exercise is voluntarily terminated.]
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