This study examined the effect of a neck cooling collar on a person’s ability to exercise in the heat. The participants were able to perform exercise for a longer period in a hot environment when their neck regions were cooled. Since the neck is close to the thermoregulatory center located at the base of brain, cooling the neck region has a direct effect on the brain’s perception of body temperature, which affects exercise performance. Cooling helps mask the heat-loss mechanism and delays exhaustion time during exercise.
This research is important for exercisers who want to increase their endurance for exercising during hot days. There are natural inhibitory signals in the human body that prevent us from continuing exercise when our core temperature is above 40 C. These signals protect us from potentially fatal heat-related illness. Since the neck is close to the thermoregulation center, it makes sense to study the effect of cooling the neck region on exercise. Cooling the neck region by using a cooling collar provides false signals to the brain that result in increased exercise performance. But cooling can be detrimental to a person’s health if false signals mask very high core temperatures. Therefore, the authors sought to determine if improved exercise ability due to using a cooling collar in a hot environment is the result of inhibiting the ability of the brain to perceive signals of high temperatures and a subsequent disregard or overriding of inhibitory signals.
* Eight men aged 24 to 28 years weighing 156 to183 pounds with a height of 5.7 to 6 feet were recruited to take part in four trials. The first two trials were no-collar. The other two trials included one with a cooling collar and a second trial either with or without a collar.
* Maximal oxygen uptake was recorded. Heart rate, rectal temperature, neck skin temperature, thermal sensation of body and neck, and exertion rate were observed at five-minute intervals and as soon as exercise ended.
* A CC, filled with gel refrigerant and placed in freezer at -80 C, was used for the experiments.
* There was approximately a 14 percent increase in exercise capability in volunteers who wore a cooling collar.
* Higher heart rates and higher rectal temperatures were found in participants wearing a cooling collar.
* There was no difference in whole body thermal sensitivity or rating of exertion between cooling collar and no collar trials.
* No difference was observed in the total sweat lost between cooling collar and no collar trials.
Some researchers have reported a connection between dopamine (a brain transmitter) levels and thermal strain. Since dopamine levels are temperature-dependent, it should also be included in the study to gain a better understanding of cooling behavior. This study was performed on eight people. More people can be recruited to obtain more comparative data.
Athletes and their support teams always seek new strategies to increase their exercising ability in hot environments. Cooling of the neck region can cause cooling of blood in arteries by which brain temperature is reduced. The decrease in brain temperature can mask the perception of body heat that would otherwise cause an exerciser to voluntary stop exercising. Although this method can be used widely, care should be taken to avoid reaching dangerously high core body temperatures.
For More Information:
Cooling the Neck Region during Exercise in the Heat
Publication Journal: Journal of Athletic Training, 2011
By Christopher James Tyler; Caroline Sunderland, Roehampton University, London, England; Nottingham Trent University, Nottingham, England