While exploring it I found some easily-digestible summaries of some fascinating track and field research studies. These summaries are so short that even the complex scientific information they contain can be absorbed within a minute or two. Here's one that is so short, I'll just quote it in its entirety:
The effects of warm-up and pre-cooling on endurance performance in high ambient temperatures
Wednesday 18 April 2007
By Sandra Ückert and Winfried Joch
It is well established that warm conditions have a detrimental effect on endurance performance. If skin temperature is exceeded by the ambient temperature, heat dissipation is impaired and heat storage is likely to occur. A warm-up, which by definition entails increasing body temperature, is generally considered a vital part of the preparation for competition - including endurance performances in hot weather. On this understanding, the question arises if cooling prior to competition (pre-cooling) might be a better alternative. Twenty subjects performed two laboratory endurance tests in conditions of high ambient temperature and relative humidity. One test followed a 20-minute warm-up and the other a 20-minute pre-cooling procedure. The comparison of results shows that pre-cooling significantly extends the time to exhaustion and slows the increase in both body core temperature and heart rate. The authors conclude that pre-cooling, as opposed to a warm-up, optimises thermoregulatory processes before physical effort in warm conditions.
I'd never imagined that a warm-up, as opposed to a hot-weather "pre-cooling" procedure, could be so detrimental to a distance runner's performance during a hot-weather race. Back in high school, we always warmed up prior to training runs and races whether it was 95° (usually late during track season) or 45° (usually late during cross-country season). The concept of a hot-weather "pre-cooling" procedure is so simple yet logical, I wonder why I hadn't thought of it myself.