The acute phase response and exercise: The ultramarathon as prototype exercise

Objective: Controversy exists in relation to the nature of the acute phase response, which is known to occur following endurance exercise. This study was conducted to demonstrate the similarities between this response and the response consequent to general medical and surgical conditions. Design: This is a case series field study of serum levels of acute phase reactants in a group of ultramarathon runners competing in a 6-day track race. Participants: Seven male and one female experienced ultramarathon runners. Intervention: A track race of 6 days duration. Main Outcome Measures: Serum iron, ferritin, transferrin, albumin, haptoglobin, alpha-1 antitrypsin, complement components 3 and 4, C-reactive protein, and erythrocyte sedimentation rate, total iron binding capacity, and transferrin saturation. Results: Of the 11 acute phase reactants measured, 6 (serum iron, ferritin, percent transferrin saturation, C-reactive protein, erythrocyte sedimentation rate, and haptoglobin) responded as if an acute phase response was present; 5 (tranferrin, albumin, alpha-1 antitrypsin, and complement components 3 and 3) did not respond in such a fashion. Conclusion: This study provides further evidence that the acute phase response consequent to exercise is analogous to that which occurs in general medical and surgical conditions. The previous demonstration of the presence of the appropriate cytokines following exercise, the findings of others in relation to acute phase reactants not the subjects of this study, the possibility that a training effect leading to attenuation of the response and the realization that the acute phase response is not identical across a range of medical conditions lends weight to the above conclusion.