Recent research suggests these kinds of experiences, also shared by winter athletes, sled dogs, meatpackers and even fisherman, may be the beginning of a cascade of events leading to more serious conditions later.
Similarly, both athletes and horses seem open to infection after such strenuous bouts of activity as handicap races or marathons. Exercise physiologists and others have long thought that over-exertion might open a kind of "window of susceptibility" for sickness, but most of the evidence is anecdotal.
Physiologists at Oklahoma State University reporting on new research believe they may have found evidence that could link the problems suffered by horses, athletes and cold-air workers that potentially could lead to progress in understanding the development and perhaps give hints toward cures for asthma and related diseases. Specifically, the Oklahoma State team reported that their research "data are the first to provide a specific mechanism for the exercise-induced open-window effect as a local pulmonary phenomenon."
The research involved horses exercising while breathing air at 23 degrees Fahrenheit and may "help explain why flu season occurs in the winter, how asthma develops in humans, and why race and other active horses get 'heaves,'" lead researcher Michael S. Davis said.
The study, entitled "Cold weather exercise and airway cytokine expression," appears in the June issue of the Journal of Applied Physiology, published by the American Physiological Society. The research was conducted by Michael S. Davis, Jerry R. Malayer, Lori VanDeventer, Christopher M. Royer, Erica C. McKenzie and Katherine K. Williamson of the Department of Physiological Sciences