Title

Ice slurry ingestion increases core temperature capacity and running time in the heat

Document Type

Journal Article

Publisher

American College of Sports Medicine

Faculty

Computing, Health and Science

School

School of Exercise, Biomedical and Health Sciences

RAS ID

8299

Comments

Originally published as: Siegel, R., Joseph, M., Brearley, M., Watson, G., Nosaka, K., & Laursen, P. (2010) Ice Slurry Ingestion Increases Core Temperature Capacity and Running Time in the Heat. Medicine and science in sports and exercise, 42 (4), 717-725 Original article available here

Abstract

Purpose: To investigate the effect of ice slurry ingestion on thermoregulatory responses and submaximal running time in the heat.

Methods: On two separate occasions, in a counterbalanced order, 10 males ingested 7.5 g·kg-1 of either ice slurry (-1°C) or cold water (4°C) before running to exhaustion at their first ventilatory threshold in a hot environment (34.0°C ± 0.2°C, 54.9% ± 5.9% relative humidity). Rectal and skin temperatures, HR, sweating rate, and ratings of thermal sensation and perceived exertion were measured.

Results: Running time was longer (P = 0.001) after ice slurry (50.2 ± 8.5 min) versus cold water (40.7 ± 7.2 min) ingestion. Before running, rectal temperature dropped 0.66°C ± 0.14°C after ice slurry ingestion compared with 0.25°C ± 0.09°C (P = 0.001) with cold water and remained lower for the first 30 min of exercise. At exhaustion, however, rectal temperature was higher (P = 0.001) with ice slurry (39.36°C ± 0.41°C) versus cold water ingestion (39.05°C ± 0.37°C). During exercise, mean skin temperature was similar between conditions (P = 0.992), as was HR (P = 0.122) and sweat rate (P = 0.242). After ice slurry ingestion, subjects stored more heat during exercise (100.10 ± 25.00 vs 78.93 ± 20.52 W·m-2, P = 0.005), and mean ratings of thermal sensation (P = 0.001) and perceived exertion (P = 0.022) were lower.

Conclusions: Compared with cold water, ice slurry ingestion lowered preexercise rectal temperature, increased submaximal endurance running time in the heat (+19% ± 6%), and allowed rectal temperature to become higher at exhaustion. As such, ice slurry ingestion may be an effective and practical precooling maneuver for athletes competing in hot environments.

 

Link to publisher version (DOI)

10.1249/MSS.0b013e3181bf257a