Running Economy And Biomechanics Of Sub-elite To Elite Distance Runners Wearing “Super” Spikes

“Super” spikes refer to track spikes constructed with increased underfoot cushioning, highly compliant and lightweight midsole foams, and rigid nylon plates spanning the shoe sole length. Similarly constructed “super” shoes have reduced the metabolic cost of running (economy) by 2.7-4.2% compared to previous generations of footwear. This improvement in economy may be due to the polyether block amide (PEBA) midsole foams used in “super” shoe and spikes and the influence on peak vertical ground reaction force (vGRF) and leg stiffness while running. Despite many studies on running economy while wearing “super” shoes, the effects of wearing “super” spikes on running economy is unknown. PURPOSE: To compare running economy and biomechanics of sub-elite to elite runners at sub-threshold effort in “super” spikes, traditional spikes, and “super” shoes. METHODS: 3 male and 3 female sub-elite to elite distance runners (10 k time < 32 & 39 min, respectively) ran eight 5-min trials (4 shoes with 2 replicates) at 15 km/h for women and 17 km/h for men in two “super” spikes (ND and OC), a traditional spike (NV), and a “super” shoe (VF) during two sessions. We calculated gross metabolic power (W/kg), peak vGRF, and leg stiffness during the last 2 min of each trial. RESULTS: We found no statistical differences (p ≥ .07) in the change in metabolic power, peak vGRF, or leg stiffness between shoe conditions. However, numerically we found running economy improved by 1.33%, 1.25%, and 1.33% while using the ND, OC, and VF, respectively, compared to the NV. Peak vGRF and leg stiffness values for ND, OC, VF, and NV were 2.92, 2.93, 2.93, and 2.93 body weights, and 17.20, 17.34, 17.44, and 17.30 kN/m. CONCLUSION: Based on the data thus far, runners wearing “super” shoes or spikes may improve running economy compared to traditional track spikes. This improvement in economy could potentially lead to 0.86% faster race times over 5000 m for runners competing in “super” spikes compared to traditional spikes.