Effects of 2.5‐hour sumo training on serum opsonic activity

Sumo is a traditional Japanese sport, but the effect of actual daily training on neutrophil function is unknown. We evaluated the effect of sumo training on serum opsonic activity (SOA), which is one of the main neutrophil‐related functions. Seventeen male university sumo wrestlers participated in the study. Changes in anthropometric parameters, concentrations of serum immunoglobulins (IgG, IgA and IgM), complements (C3 and C4), myogenic enzymes (lactate dehydrogenase, asparate aminotransferase, alanine aminotransferase and creatine kinase), white blood cell/neutrophil counts and SOA were measured immediately before and after actual daily training for 2.5 h. Compared with the pre‐values, immunoglobulins and complements, myogenic enzymes and white blood cell/neutrophil counts significantly increased (p <0.01 for all). As for SOA, the values of the peak height and the area under the curve significantly increased after the training when assessed using lucigenin as a chemiluminigenic probe (p <0.01 for all), but showed no significant change when luminol was used as the chemiluminigenic probe. In conclusion, daily actual sumo training for 2.5 h increases SOA, thus possibly activating the reactive oxygen species production of neutrophils. Copyright © 2009 John Wiley & Sons, Ltd.