Running Economy of Highly-Trained Distance Runners in Marathon Racing Shoes compared to Track Spikes

Abstract

Running economy represents a complex interplay of physiological and biomechanical factors that are able to adapt chronically through training or acutely through other interventions such as changes in footwear. The Nike Vaporfly (NVF) shoe was designed for marathon running on the roads and has been shown to improve running economy by ~4% compared to other marathon shoes, however, during track racing distance runners traditionally wear a much lighter shoe with an embedded spike plate around the forefoot. PURPOSE: To determine if, and to what extent, the NVF shoes improve running economy compared with established track spikes (SPIKE) and marathon racing shoes (MAR). METHODS: 24 highly-trained runners (12 male, 12 female) ran 4x5 min trials on a treadmill while wearing each of the four shoe conditions: NVF, SPIKE, MAR, and the NVF matched in weight to the MAR shoe (NVF+), during three separate visits: (Visit 1) familiarization; (Visit 2) 14 and 18 km.h-1 run for men, 14 and 16 km.h-1 for women; (Visit 3) 16 km.h-1 run for men, 15 km.h-1for women plus a VO2max test for both genders. We measured rates of oxygen uptake (VO2), carbon dioxide production (VCO2) and biomechanical measures (stride rate, contact time, stride length, flight time) were made at each run velocity and shoe condition. Differences in running economy while running in the four shoe conditions over three velocities was assessed using a two-way ANOVA with repeated measures. Multiple regression analyses were used to evaluate potential relationships between changes in biomechanical measures and running economy. RESULTS: The NVF shoe improved running economy by 2.6 ± 1.3% compared to SPIKE, 4.2 ± 1.2% compared to MAR, and 2.9 ± 1.3% when matched in weight of the MAR shoe. Among the 24 subjects, the difference in running economy over the four velocities between the NVF and SPIKE shoes ranged from +0.50 to -5.34% and from -1.72 to -7.15% for NVF versus MAR. Correlations between changes in running economy and changes in biomechanical variables were either trivial or small (r < 0.27) but unclear. CONCLUSION: The NVF enhanced running economy compared to track spikes and marathon shoes and should be considered a viable shoe option for track and road racing.