Practical neck cooling and time-trial running performance in a hot environment

Abstract

The aim of this two-part experiment was to investigate the effect of cooling the neck on time-trial performance in hot conditions (~30°C; 50% RH). In Study A, nine participants completed a 75-min submaximal (~60% V(O₂(max)) pre-load phase followed by a 15-min self-paced time-trial (TT) on three occasions: one with a cooling collar (CC(90)), one without a collar (NC(90)) and one with the collar uncooled (C(90)). In Study B, eight participants completed a 15-min TT twice: once with (CC(15)) and once without (NC(15)) a cooling collar. Time-trial performance was significantly improved in Study A in CC(90) (3,030 ± 485 m) compared to C(90) (2,741 ± 537 m; P = 0.008) and NC(90) (2,884 ± 571 m; P = 0.041). Fifteen-minute TT performance was unaffected by the collar in Study B (CC(15) = 3,239 ± 267 m; NC(15) = 3,180 ± 271 m; P = 0.351). The collar had no effect on rectal temperature, heart rate or RPE. There was no effect of cooling the neck on S100β, cortisol, prolactin, adrenaline, noradrenaline or dopamine concentrations in Study A. Cooling the neck via a cooling collar can improve exercise performance in a hot environment but it appears that there may be a thermal strain threshold which must be breached to gain a performance benefit from the collar.

Neck Cooling and Running Performance in the Heat

“…It is worth noting that wearing the collar uncooled impaired performance compared with the CC trials but had no effect compared with no-cooling, control trials (35). Despite alterations in running performance and capacity, cooling the neck via the practical CC and wearing the collar uncooled had no effect on any of the physiological or neuroendocrinological variables measured (34,35); a result that replicated those reported by previous neck cooling studies (5,13).…”

“…As a result, more practical alternatives have been investigated, such as the wearing of a cooling jacket or vest (1,10,11,38) or a cooling collar (CC) (5,13,34,35). Most of these studies have reported that such devices were unable to provide a sufficiently sustained cooling effect to elicit physiological alterations, and this is particularly the case with the neck cooling devices that have been investigated so far (5,13,34,35).…”

“…Cooling the head via a water-perftjsed garment has been shown to improve time trial performance in a hot environment (25), while cooling the neck region via a practical CC has been shown to significantly enhance 15-min preloaded treadmill time trial performance (35) as well as treadmill running capacity (34) in hot environmental conditions (30°C-32°C and -50% relative humidity (RH)). It is worth noting that wearing the collar uncooled impaired performance compared with the CC trials but had no effect compared with no-cooling, control trials (35).…”

“…Cooling the head via a water-perftjsed garment has been shown to improve time trial performance in a hot environment (25), while cooling the neck region via a practical CC has been shown to significantly enhance 15-min preloaded treadmill time trial performance (35) as well as treadmill running capacity (34) in hot environmental conditions (30°C-32°C and -50% relative humidity (RH)). It is worth noting that wearing the collar uncooled impaired performance compared with the CC trials but had no effect compared with no-cooling, control trials (35). Despite alterations in running performance and capacity, cooling the neck via the practical CC and wearing the collar uncooled had no effect on any of the physiological or neuroendocrinological variables measured (34,35); a result that replicated those reported by previous neck cooling studies (5,13).…”

Effects of heat acclimation on hand cooling efficacy following exercise in the heat

“…Current modalities used to aid in the prevention, not treatment, of hyperthermia include cooling collars and vests, ice packs and towels, fans, and cold water immersion (DeMartini et al, 2011;Tyler, Wild, & Sunderland, 2010). Additionally, hand cooling devices are unique given the palmar surface area cooled contains vascular networks referred to as arteriovenous anastomoses (Sangiorgi et al, 2004).…”