The influence of midsole cushioning on mechanical and hematological responses during a prolonged downhill run

The purpose of this study was to investigate the influence of midsole durometer on mechanical and hematological responses during a prolonged downhill run. Twenty-four men completed a 30-min downhill run (-12% grade) wearing either soft, medium, at-hard midsole shoes. Data describing mean peak tibial acceleration (PTA), stride frequency, plasma free hemoglobin, hemoglobin concentration, hematocrit, and creatine kinase (CK) were collected. While there were no significant differences in PTA among midsole durometer shoes, PTA increased by 20% after the first 5 min of the run over all other time intervals during the run (p < .05). Hemolysis showed a 50.2% increase from prerun to postrun values (p < .05). CK increased from the prerun state to 24 hr after the run (p < .05). Downhill run ning, irrespective of midsole durometer showed increased levels of leg shock, hemolysis, and muscle damage over values that are present in the literature for a level running protocol.