Author(s)

Erich Hohenauer^1,2,3, Rahel Stoop¹, Peter Clarys³, Ron Clijsen^1,2,3, Tom Deliens³, Jan Taeymans^3,4

¹Research Rehabilitation 2rLab, Department of Business Economics, Health and Social Care, University of Applied Sciences and Arts of Southern Switzerland, Landquart, Switzerland.
²THIM University of Applied Sciences, Landquart, Switzerland.
³Department of Movement and Sport Sciences, Vrije Universiteit Brussel, Brussels, Belgium.
⁴Health Department, Bern University of Applied Sciences, Berne, Switzerland.

Exercising in high environmental temperatures may cause precocious hyperthermia induced fatigue resulting in a decreased athletes’ performance output. This systematic review with meta-analysis investigated the possible effects of pre-exercise cooling on performance output. This study was performed according to the PRISMA guidelines and the PICO-model was used to establish the research question. The Cochrane Risk of Bias Tool was applied to assess the validity of the included studies. Study eligibility was given when the studies compared the effects between any kind of pre-cooling and non-cooling strategies prior to exercise on performance output. Twenty-nine studies met the inclusion criteria for quantitative analysis. Risk of bias was high or unclear but the performance bias was low. The estimated standardized mean difference revealed that external pre-cooling (21 studies) enhanced performance (Hedges’ g = 0.49 [95% CI: 0.33 to 0.64]), with the main effect observed in endurance cycling or running. Internal (7 studies) and mixed-method (5 studies) pre-cooling failed to significantly affect performance parameters. However, the main output parameter, evaluated in these studies, was peak power output. Subgroup analysis for different outcome measures was not possible because meaningful grouping was not plausible. Limitations of this meta-analysis were the high or unclear risk of bias and the comparability of the included studies. Future studies should also determine the effects of different pre-cooling applications on female and untrained participants. Based on the results of this meta-analysis, it can be concluded that there is some evidence in favour of external pre-cooling to avoid precocious hyperthermia induced fatigue in endurance athletes exercising in hot environments.

Performance Cooling, Precooling, Core Temperature, Exercise, Meta-Analysis

Hohenauer, E. , Stoop, R. , Clarys, P. , Clijsen, R. , Deliens, T. and Taeymans, J. (2018) The Effect of Pre-Exercise Cooling on Performance Characteristics: A Systematic Review and Meta-Analysis. International Journal of Clinical Medicine, 9, 117-141. doi: 10.4236/ijcm.2018.93012.