|Effects of Strenuous Exercise on Immune Function|
The impact of exercise on the immune system is likely related to the type, intensity, and duration of exercise. In human endurance runners, extreme exercise leads to the systemic release of several inflammatory cytokines including IL-6, IL-1, and TNF.
These cytokines are well known mediators of local and systemic inflammation. In previous studies from this laboratory a number of exercise-induced inflammatory conditions have been characterized in racing sled dogs. Future studies will investigate the role of cytokines in extreme exercise in the Alaskan sled dog, and there association with fatigue and exercise induced inflammation.
Strenuous exercise in cold environments is a risk factor for lower respiratory disease. Exercise while breathing cold air is known to result in the exposure of lower airways to unconditioned air, with subsequent airway cooling and desiccation. It is widely appreciated that racehorses have a high incidence of subclinical lower respiratory inflammation. Recent information from other studies of strenuous exercise confirms that cold inspired air during exercise induces airway disease, and may increase susceptibility of the subject to inhaled pathogens. Horses have significant upregulation of airway TH2 cytokines and increased mucosal permeability after a single episode of strenuous exercise while breathing cold air. These changes may lead to increased susceptibility to airborne pathogens. We believe that these proteins decrease the horse