The effects of crushed ice ingestion prior to steady state exercise in the heat

Matthew Zimmermann, Grant Landers, Karen E. Wallman, Jacinta Saldaris

    Research output: Contribution to journalArticle

    8 Citations (Scopus)

    Abstract

    This study examined the physiological effects of crushed ice ingestion before steady state exercise in the heat. Ten healthy males with age (23 ± 3 y), height (176.9 ± 8.7 cm), body-mass (73.5 ± 8.0 kg), VO2peak (48.5 ± 3.6 mL·kg·min-1) participated in the study. Participants completed 60 min of cycling at 55% of their VO2peak preceded by 30 min of precooling whereby 7 g·kg-1 of thermoneutral water (CON) or crushed ice (ICE) was ingested. The reduction in Tc at the conclusion of precooling was greater in ICE (-0.9 ± 0.3 °C) compared with CON (-0.2 ± 0.2 °C) (p £.05). Heat storage capacity was greater in ICE compared with CON after precooling (ICE-29.3 ± 4.8 W·m-2; CON-11.1 ± 7.3 W·m-2, p <.05). Total heat storage was greater in ICE compared with CON at the end of the steady state cycle (ICE 62.0 ± 12.5 W·m-2; CON 49.9 ± 13.4 W·m-2, p <.05). Gross efficiency was higher in ICE compared with CON throughout the steady state cycle (ICE 21.4 ± 1.8%; CON 20.4 ± 1.9%, p <.05). Ice ingestion resulted in a lower thermal sensation at the end of precooling and a lower sweat rate during the initial stages of cycling (p <.05). Sweat loss, respiratory exchange ratio, heart rate and ratings of perceived exertion and thirst were similar between conditions (p >.05). Precooling with crushed ice led to improved gross efficiency while cycling due to an increased heat storage capacity, which was the result of a lower core temperature.

    Original languageEnglish
    Pages (from-to)120-127
    Number of pages8
    JournalInternational Journal of Sport Nutrition and Exercise Metabolism
    Volume27
    Issue number3
    DOIs
    Publication statusPublished - 1 Jun 2017

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