J Athl Train. 2011 Jan-Feb;46(1):61-8. doi: 10.4085/1062-6050-46.1.61.

Cooling the neck region during exercise in the heat.

Source

Human and Life Sciences, Whitelands College, Roehampton University, London, United Kingdom. Chris.Tyler@roehampton.ac.uk

Abstract

CONTEXT:

Cooling the neck region can improve the ability to exercise in a hot environment. It might improve performance by dampening the perceived level of thermal strain, allowing individuals to override inhibitory signals.

OBJECTIVE:

To investigate whether the enhanced ability to exercise in a hot environment observed when cooling the neck region occurs because of dampening the perceived level of thermal strain experienced and the subsequent overriding of inhibitory signals.

DESIGN:

Crossover study.

SETTING:

Walk-in environmental chamber.

PATIENTS OR OTHER PARTICIPANTS:

Eight endurance-trained, nonacclimated men (age = 26 ± 2 years, height = 1.79 ± 0.04 m, mass = 77.0 ± 6.2 kg, maximal oxygen uptake [V˙O(2max)] = 56.2 ± 9.2 mL·kg(-1)·min(-1)) participated.

INTERVENTION(S):

Participants completed 4 running tests at approximately 70% V˙O(2max) to volitional exhaustion: 2 familiarization trials followed by 2 experimental trials (cooling collar [CC] and no collar [NC]). Trials were separated by 7 days. Familiarization and NC trials were performed without a collar and used to assess the test variability.

MAIN OUTCOME MEASURE(S):

Time to volitional exhaustion, heart rate, rectal temperature, neck skin temperature, rating of perceived exertion, thermal sensation, and feeling scale (pleasure/displeasure) were measured.

RESULTS:

Time to volitional exhaustion was increased by 13.5% ± 3.8% (CC = 43.15 ± 12.82 minutes, NC = 38.20 ± 11.70 minutes; t(7) = 9.923, P < .001) with the CC, which reduced mean neck skin temperature throughout the test (P < .001). Participants terminated exercise at identical levels of perceived exertion, thermal sensation, and feeling scale, but the CC enabled participants to tolerate higher rectal temperatures (CC = 39.61°C ± 0.45°C, NC = 39.18°C ± 0.7°C; t(7) = -3.217, P = .02) and heart rates (CC = 181 ± 6 beats/min, NC = 178 ± 9 beats/min; t(7) = -2.664, P = .03) at the point of termination.