Small Performance Effects of a Practical Mixed-Methods Cooling Strategy in Elite Team Sport Athletes

ABSTRACT

Purpose: The ingestion of ice slurry and application of ice towels can elicit favorable physiological, perceptual, and performance benefits when used individually; however, the combined use and effectiveness of these practical cooling strategies have not been assessed using a sport-specific performance test, based on actual match demands, in an elite team sport context. Methods: Ten non-heat acclimated elite male rugby sevens athletes undertook two cycling heat response tests (HRT) designed to be specific to the demands of rugby sevens in hot conditions (35°C, 80% rH). In a crossover design, the HRTs were conducted with (COOLING) and without (HOT) the combined use of internal (ice slushy ingestion) and external (application of ice towels to the head, neck, and face) pre- and per-cooling strategies. Physiological, perceptual, and performance variables were monitored throughout each HRT. Results: COOLING resulted in reductions in mean tympanic temperature (−0.4 ± 0.2°C; d = 1.18); mean heart rate (−5 ± 8 bpm; d = 0.53); thermal discomfort (−0.5 ± 0.9 AU; d = 0.48); and thirst sensation (−1.0 ± 1.1 AU; d = 0.61) during the HRT. COOLING also resulted in a small increase in 4-min time trial power output (by 7 ± 33 W, ~3%; d = 0.35) compared to HOT. Discussion: A combination of internal and external pre- and per-cooling strategies can result in a range of small physiological, perceptual, and performance benefits during a rugby sevens specific HRT, compared to undertaking no cooling. Practitioners should include such strategies when performing in hot conditions.

KEYWORDS:

• Exercise
• heat
• per-cooling
• pre-cooling
• thermoregulation

Acknowledgments

The authors would like to thank the athletes, coaches, and management of the All Blacks sevens team for engaging in this research project. We also acknowledge the contribution to data collection from Conor McNeil and Christian Chavarro of the University of Waikato.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Statements and declarations

The procedures of this study were approved by the Human Research Ethics Committee at the University of Waikato (HREC2018#64).

Author contributions

SF and CMB conceived and designed the research, conducted the research protocols, and processed/analyzed the data; MD and NG helped design the research; BM and FS conceived and designed the research, and conducted the research protocols. All authors contributed to the final editing and revision of the manuscript. All authors have read and approved the final manuscript and agree with the order of presentation of the authors.

Additional information

Funding

The author(s) reported that there is no funding associated with the work featured in this article.