Combined active and passive heat exposure induced heat acclimation in a soccer referee before 2014 FIFA World Cup.

A D Ruddock,S W Thompson,C A James,J A Mee,O R Gibson,S A Hudson

doi:10.1186/s40064-016-2298-y

Abstract

IntroductionThe 2014 FIFA World Cup was held in Brazil, where the climatic conditions presented a significant thermoregulatory and perceptual challenge to those unfamiliar with the heat and humidity.Case presentationThis case report documents the adaptation induced by a novel mixed methods (isothermic and passive) heat acclimation (HA) regime for a northern European professional soccer match official prior to the tournament. The intervention involved 13 HA sessions over an 18 day period comprising five isothermic HA sessions whereby intermittent running was used to target and maintain tympanic temperature (Tytemp) at 38 °C for 90 min, and seven passive HA sessions of 48 °C water bathing for 30 min. The athlete performed a heat stress test (HST) (35 min running at four incremental intensities in 30 °C) and a repeated high-intensity running test (as many 30 s self-paced efforts as possible, to a maximum of 20, with 30 s passive recovery) before and after the intervention. The mixed methods HA regime increased plasma volume (+7.1 %), and sweat loss (+0.9 L h−1), reduced exercising Tytemp (−0.6 °C), and mean body temperature (−0.5 °C). High-intensity running performance improved after HA (+29 %), as did the perception of thermal comfort during exercise (−0.3 units).ConclusionThis data evidences the effectiveness of a practical, mixed methods HA strategy, remotely implemented around training and competition, at inducing the heat acclimation phenotype in a high-level soccer match official.

Highlights

The 2014 FIFA World Cup was held in Brazil, where the climatic conditions presented a significant thermoregulatory and perceptual challenge to those unfamiliar with the heat and humidity.Case presentation: This case report documents the adaptation induced by a novel mixed methods heat acclimation (HA) regime for a northern European professional soccer match official prior to the tournament
This data evidences the effectiveness of a practical, mixed methods HA strategy, remotely implemented around training and competition, at inducing the heat acclimation phenotype in a high-level soccer match official
Evidence highlights marked changes to soccer performance in the region as a consequence of heat stress, with a reduced number of sprints performed by players (−10 %), compared moderate and low heat stress, and a reduction in the distance covered at a high intensity (−2.1 m min−1 player) (Nassis et al 2015)

Summary

Conclusion

This is the first evidence that a novel mixed methods HA regime that combined active and passive heat exposures over a period of 18 days. Authors’ contributions All authors contributed to the preparation of this manuscript. SH: design, data collection, data analysis, preparation of manuscript. JM: design, data analysis, preparation of manuscript. Author details 1 A016 Collegiate Hall, Centre for Sport and Exercise Science, Sheffield Hallam University, Sheffield, South Yorkshire S10 2BP, UK. 2 Academy of Sport and Physical Activity, A209 Collegiate Hall, Sheffield Hallam University, Collegiate Crescent Campus, Eccelsall Road, Sheffield S10 2BP, UK. 4 Environmental Extremes Laboratory, Centre for Sport and Exercise Science and Medicine (SESAME), University of Brighton, Welkin Laboratories, Denton Road, Eastbourne, East Sussex BN20 7SR, UK. 5 Centre for Sports Medicine and Human Performance (CSMHP), Heinz Wolff Building, Brunel University London, Uxbridge UB8 3PH, UK.

Background

Results