Those heading to Ironman Arizona and Ironman Florida from cooler environments should consider strategies for acclimating to heat and humidity for the race. IMAZ folks living in cool climates should be over-dressing now. See strategies in the two-part column, Acclimating to Heat and Humidity.
Awhile back I wrote a column about pre-cooling for racing. Researchers in Singapore recently published a study looking at ingesting an ice slurry before running a 10k. This means of pre-cooling before a hot race is practical and easy for most athletes.
The twelve participants ingested either an ice slurry (approximately 30 degrees Fahrenheit) or an ambient temperature drink (approximately 88 degrees Fahrenheit) prior to their 15-minute warm-up. They consumed 8 grams of slurry or ambient drink per kilogram of body weight.
A couple of interesting things happened. First, the slurry drinkers experienced a rise in gastrointestinal temperature. I’m assuming this is the body’s response to the cold drink, increasing temperature to warm the solution for digestion.
Even with a transient temperature increase, the slurry drinkers had improved mean performance by 15 seconds for the entire 10k. The slurry runners’ mean pace was 7:18 per mile and the ambient solution drinkers ran 7:20.
If you are consuming fluids pre-race anyway, consuming an ice slurry drink may improve your performance.
Yeo, Z.W. et al, “Ice Slurry on Outdoor Running Performancein Heat”, International Journal of Sports Medicine: Issue EFirst, 2012.