A Biomechanical And Physiological Comparison Of The Nike Vaporfly And Nike Zoom Rival Spikes

Abstract

Nike has claimed that Vaporfly (VF) shoes will decrease an individual’s racing marathon time by 4%. Several investigators have examined the performance effects of wearing the Nike VF shoes on running economy and marathon running pace. Researchers have shown that the VF shoes out-perform other popular racing shoes, resulting in improved running economy, lower oxygen needs, and improved running mechanics at the slower performance velocities. However, the theoretical biomechanical and physiological costs associated with wearing the VF shoes versus a traditional racing spike at 1500 m pace has not been examined. PURPOSE: To compare the biomechanical and physiological response of highly trained collegiate distance runners wearing the Nike VF and Nike Zoom Rival D 10 (RD) spikes during a 1500 m time trial (TT). METHODS: Sixteen (9F, 7 M) highly trained collegiate distance runners (20 ± 2 yrs) completed a randomized crossover testing protocol utilized during three laboratory sessions. Session one included collection of baseline metabolic measures and establishing VO2peak. The second and third sessions assessed the participants’ biomechanical and physiological responses at 14 and 16 kph and 1500 m-time trial performance in each footwear in a randomized counterbalanced manner. Seven days separated each of the three testing sessions. For baseline measures, participants completed a continuous treadmill test consisting of 3-min stages beginning at 11 kph for females and 12 kph for males set at a 1.0% gradient and increasing at 1 kph increments until volitional exhaustion. Running economy (RE) at 14 and 16 kph and 1500 m-TT performance in VF and RD were assessed on the second and third visits following a force plate assessment. Footwear comparisons were made via paired T-Tests utilizing both effect size and p values. RESULTS: RE (VO2 for 1 km in ml*min-1) at 14 and 16 kph were less in the VF than RD (189 ± 9 vs 195 ± 8 ml*min-1 (ES .778) and 190 ± 10 vs 195 ± 11 ml*min-1 (ES .501), respectively, p < 0.05). Stride length during the TT was greater in the VF than RD by 12 cm (3.19 ± 0.36 vs 3.07 ± .37, ES .930, p < .05). 1500 m TT was faster with VF than RD (299.2 ± 42.4 vs 305.2 ± 41.0 s, ES .530, p < 0.05). CONCLUSION: The use of the VF resulted in improved (2%) 1500 m TT performance compared to RD primarily due to improved RE values and longer stride length for VF trials.