Hand and torso pre-cooling does not enhance subsequent high-intensity cycling or cognitive performance in heat

ABSTRACT

The purpose of this study was to compare the separate and combined effects of two practical cooling methods (hand and torso) used prior to exercise on subsequent high-intensity cycling performance in heat. Ten trained male cyclists (V̇O₂peak: 65.7 ± 10.7 ml.kg⁻¹.min⁻¹) performed four experimental trials (randomised within-subjects design) involving 30-min of pre-cooling (20-min seated; PRE-COOL, 10 min warm-up; PRE-COOL+WUP), while using a: (1) hand-cooling glove (CG); (2) cooling jacket (CJ); (3) both CG and CJ (CG+J); or (4) no-cooling (NC) control, followed by a cycling race simulation protocol (all performed in 35.0 ± 0.6°C and 56.6 ± 4.5% RH). During the 30-min of pre-cooling, no reductions in core (Tc) or mean skin temperature (Tsk) occurred; however, Tsk remained lower in the CJ and CG+J trials compared to NC and CG (p = 0.002–0.040, d= 0.55–1.01). Thermal sensation ratings also indicated that participants felt “hotter” during NC compared to all other trials during both PRE-COOL and PRE-COOL+WUP (p = 0.001–0.015, d= 1.0–2.19), plus the early stages of exercise (sets 1–2; p = 0.005–0.050, d= 0.56–1.22). Following cooling, no differences were found for absolute Tc and Tsk responses between trials over the entire exercise protocol (p > 0.05). Exercise and cognitive (working memory) performance also did not differ between trials (p = 0.843); however, cognitive performance improved over time in all trials (p < 0.001). In summary, pre-cooling (20-min seated and 10-min warm-up) in heat did not improve subsequent high-intensity cycling performance, cognitive responses and associated thermoregulatory strain (Tc and Tsk) compared to control.

KEYWORDS:

• Core temperature
• thermoregulation
• hand cooling
• cooling jacket
• thermal sensation
• working memory

Acknowledgments

The authors would like to thank the participants for their time and commitment to this study and Industrial Protective Products (IPP) Western Australia for supplying the CoreControl^TM units.

Abbreviations

BLa	=	Blood lactate
bpm	=	beats per minute
BSA	=	Body surface area
CG	=	Cooling glove
CG+J	=	Cooling glove and jacket
CJ	=	Cooling jacket
CWI	=	Cold water immersion
ES	=	Effect size
HR	=	Heart rate
NC	=	No-cooling
RH	=	Relative humidity
RPE	=	Rating of perceived exertion
Tc	=	Core temperature
TS	=	Thermal sensation
Tsk	=	Skin temperature
WUP	=	Warm up

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplementary material

Supplemental data for this article can be accessed here.