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Updated: May 21, 2026
08:16
Ice Generation and the Heat and Mass Transfer Phenomena of Introducing Water to a Cold Bath of Brine
Published on: March 13, 2017
Ice slurry on outdoor running performance in heat
Z W Yeo1, P W P Fan, A Q X Nio
1Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore.
International Journal of Sports Medicine
|June 26, 2012
Summary
Ingesting ice slurry before outdoor running improves 10 km time-trial performance. This pre-competition cooling strategy effectively enhances endurance in warm, humid conditions despite a temporary increase in heat strain.
Area of Science:
- Exercise Physiology
- Environmental Physiology
- Sports Science
Background:
- Endurance performance is significantly impacted by heat stress.
- Pre-cooling strategies are employed to mitigate heat strain during exercise.
- The efficacy of ice slurry ingestion for outdoor endurance performance remains under-investigated.
Purpose of the Study:
- To investigate the effect of ice slurry ingestion on 10 km outdoor running time-trial performance.
- To assess physiological responses, including gastrointestinal temperature and thermal sensation, to ice slurry ingestion.
- To determine the practicality and effectiveness of ice slurry as a pre-competition cooling intervention.
Main Methods:
- Twelve participants completed a 10 km outdoor running time-trial under warm and humid conditions (Wet Bulb Globe Temperature: 28.2 ± 0.8°C).
- Participants ingested either ice slurry (-1.4°C) or an ambient temperature drink (30.9°C) before a standardized warm-up and the time-trial.
- Key metrics included performance time, gastrointestinal temperature (Tgi), and thermal sensation ratings.
Main Results:
- Mean performance time was significantly faster with ice slurry ingestion (2715 ± 396 s) compared to the control drink (2730 ± 385 s; P=0.023).
- Ice slurry ingestion led to a greater reduction in Tgi post-ingestion but a faster rate of Tgi rise during the initial 15 minutes of exercise.
- End-of-trial Tgi was higher with ice slurry (40.2 ± 0.6°C) versus control (39.8 ± 0.4°C), and thermal sensation was lower during cooling and the first kilometer.
- A transient increase in heat strain was observed post-warm-up with ice slurry.
Conclusions:
- Ice slurry ingestion is a practical and effective pre-competition cooling strategy for improving 10 km running performance in warm and humid environments.
- While causing a transient increase in heat strain, the overall benefits to performance outweigh this temporary effect.
- This cooling maneuver offers a viable method for athletes to enhance endurance in challenging environmental conditions.
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