Heat injuries among recreational runners.

With the increasing popularity of jogging and competitive running, more people are participating in races, particularly during the warm months. In the Southeastern United States, the combination of high temperatures and high relative humidity appears to be responsible for many heat-associated injuries. We studied the training, racing, and selected personal characteristics of heat-injured and age- and sex-matched uninjured recreational runners at four races. The major differences between the two groups were that injured runners had not been running as long, ran fewer miles per week, ran fewer miles per training run, and were more likely to be caught up in the excitement of the event.