Research

SIEGEL R, MATÉ J, BREARLEY MB, WATSON G, NOSAKA K, LAURSEN PB. ICE SLURRY INGESTION INCREASES CORE TEMPERATURE CAPACITY AND RUNNING TIME IN THE HEAT. MED SCI SPORTS EXERC. 2010 APR;42(4):717-25.

This study was the first to show the beneficial effect of ice slushy ingestion on prolonged running in the heat. Subjects ingested around half a litre of either cold water (4°C) or ice slushy (-1°C) in the 30-minute period prior to steady state running in the heat and ran nearly 20% longer when they ingested ice slushy.

STEVENS CJ, DASCOMBE B, BOYKO A, SCULLEY D, CALLISTER R. ICE SLURRY INGESTION DURING CYCLING IMPROVES OLYMPIC DISTANCE TRIATHLON PERFORMANCE IN THE HEAT. J SPORTS SCI. 2013 MAR 18. [EPUB AHEAD OF PRINT].

Well-trained triathletes ingested either ice slushy or warm fluids during a 1-h simulated cycle phase of an Olympic distance triathlon in hot conditions. Subsequently, 10 km run performance was improved by more than a minute (+3%) when ice slushy was ingested on the bike compared to warm fluids. Ice slushy lowered the triathlete’s internal temperatures and perceived thermal strain.

YEO ZW, FAN PW, NIO AQ, BYRNE C, LEE JK. ICE SLURRY ON OUTDOOR RUNNING PERFORMANCE IN HEAT. INT J SPORTS MED. 2012 NOV;33(11):859-66. EPUB 2012 JUN 22.

Completed in hot and humid Singapore, the authors showed that outdoor 10 km run performance time was improved by 15 seconds when ice slushy was ingested compared with ambient temperature fluid in hot conditions. Athletes felt cooler during the first kilometer of the run when they ingested ice slushy.

SIEGEL R, LAURSEN PB. KEEPING YOUR COOL: POSSIBLE MECHANISMS FOR ENHANCED EXERCISE PERFORMANCE IN THE HEAT WITH INTERNAL COOLING METHODS. SPORTS MED. 2012 FEB 1;42(2):89-98.

A review of the ice slushy research findings to date, with suggestions as to how ice slushy ingestion may function to enhance performance in hot conditions.

ROSS ML, GARVICAN LA, JEACOCKE NA, LAURSEN PB, ABBISS CR, MARTIN DT, BURKE LM. NOVEL PRECOOLING STRATEGY ENHANCES TIME TRIAL CYCLING IN THE HEAT. MED SCI SPORTS EXERC. 2011 JAN;43(1):123-33.

Well trained cyclists ingested either half a litre of ice slushy drink or cold water before a simulated Beijing Olympic Time Trial in hot and humid conditions. Ice slushy ingestion improved cycling power output by 8 W or 3%, which equated to a 1.3% improvement in performance time.

IHSAN M, LANDERS G, BREARLEY M & PEELING P (2010). BENEFICIAL EFFECTS OF ICE INGESTION AS A PRECOOLING STRATEGY ON 40 KM CYCLING TIME-TRIAL PERFORMANCE. INT J SPORTS PHYSIOL PERFORM 5, 140-151.

This study compared the ingestion of ice slurry versus tap water in the 30 min period prior to a simulated 40-km time trial performed in hot conditions. Ice slushy ingestion lowered core temperature and improved time trial performance by 6.5% compared with warm tap water.

BURDON CA, HOON MW, JOHNSON NA, CHAPMAN PG, O’CONNOR HT. THE EFFECT OF ICE SLUSHY AND MOUTHWASH ON THERMOREGULATION AND ENDURANCE PERFORMANCE IN THE HEAT. INT J SPORT NUTR EXERC METAB. 2013 MAR 26. (EPUB AHEAD OF PRINT).

Subjects performed three different drinking trials during 90 min of steady state cycling in the heat prior to a time trial performance: 1) ingesting ice slushy, 2) mouth-rinsing but not ingesting ice slushy (i.e., spitting it out), or 3) ingesting warm liquid. Ice slushy ingestion improved perceived exertion, thermal comfort and performance the most, but even simply the presence of ice slushy in the mouth (i.e., mouth rinsing) showed meaningful performance improvements compared with warm liquid.

SIEGAL R, MATÉ J, WATSON G, NOSAKA K, LAURSEN PB. PRE-COOLING WITH ICE SLURRY INGESTION LEADS TO SIMILAR RUN TIMES TO EXHAUSTION IN THE HEAT AS COLD WATER IMMERSION. J SPORT SCI. 2012;30(2):155-65.

Study compared precooling with ice slurry ingestion to the standard cold water immersion technique, and found ice slurry ingestion to be just as effective as using cold water immersion before exercise in hot conditions.

SIEGEL R, MATÉ J, WATSON G, NOSAKA K, LAURSEN PB. THE INFLUENCE OF ICE SLURRY INGESTION ON MAXIMAL VOLUNTARY CONTRACTION FOLLOWING EXERCISE-INDUCED HYPERTHERMIA. EUR J APPL PHYSIOL. 2011 OCT;111(10):2517-24.

Maximal 2 minute sustained effort was enhanced by 6.7% when subjects swallowed a mouthful of ice slurry compared with warm liquid after exercising to exhaustion in the heat.