THE EFFECT OF RACING SHOE MIDSOLE COMPOSITION ON UPHILL, DOWNHILL AND LEVEL RUNNING ECONOMY 275

Abstract

It has been suggested that greater shoe cushioning may improve running economy (RE) and improve endurance running performance. Frederick et al.(1982) (12(2), MSSE) reported a 2.4% improvement in RE when running in shoes designed with an encapsulated gas midsole (AIR) as compared with the traditional ethylene vinyl acetate midsole (EVA). The purpose of this study was to compare the effect of racing shoe midsole composition (AIR vs. EVA) on RE, stride length (SL) & heart rate (HR) while running at different velocities and grades. Eight competitive male distance runners performed two series of RE tests at velocities ranging from 7-10 mph and grades ranging from-5 to +5%. Using a randomized design, one test was performed wearing an AIR racing shoe and the other test performed wearing an EVA racing shoe. Both shoes were built on the same last with the only difference being the AIR shoe weighing ≈ 30 grams more than the EVA shoe. Paired t-tests were used to compare the effect of the two midsole types on VO2, SL & HR at each running velocity and grade. Statistical significance was set at P ≤ 0.05. The results revealed that regardless of the running velocity or grade, there were no significant differences between shoe types on any of the dependent variables. These findings are in contrast with the results of previous studies and suggest that the AIR midsole does not improve RE.