Running Economy Benefits of Advanced Footwear Technologies Remain over a Prolonged Run in Highly Trained Distance Runners—A Randomized Crossover Trial
Lars Christian Schwalm, Dominik Fohrmann, Marcelle Schaffarczyk, A Herrmann, Thomas Gronwald, Karsten Hollander
Abstract
PURPOSE: Running economy (RE) improvements in advanced footwear technologies (AFTs) have been investigated during short running bouts, whereas performance-enhancing effects may be greater over longer distances. Therefore, the aim was to compare RE and biomechanics during a 90-min run between AFTs and traditional shoes in highly trained distance runners. METHODS: Nine highly trained distance runners (five females) visited our laboratory on two separate sessions within 14 d. In each session, they performed a submaximal threshold assessment treadmill test, followed by a 90-min treadmill run. We used linear mixed effects models (with random intercepts for participants) to examine the effects of time, shoe condition, and their interaction on energetic cost of transport (ECOT) and biomechanical measures. RESULTS: Participants (age: 32.4 ± 8.4 yr, body mass index: 20.8 ± 1.2 kg·m -2 ) had a mean maximal World Athletics score of 930 ± 84 points, corresponding to 10 km times (min:s) of 30:17 and 36:09 for males and females. ECOT was different between AFT and non-AFT ( β = 0.57 (0.41-0.72), P = 0.009) throughout 15 to 90 min. On average, ECOT was 3.18% (95% confidence interval, 2.14-4.22) lower in the AFTs compared with the non-AFT condition. Over time, ECOT ( β = 0.30 (0.19-0.41), P < 0.001) increased by 5.63% (95% confidence interval, 3.00-8.27) across both shoe conditions, but was not shoe-dependent (ECOT: P = 0.553). With AFTs, step rate was lower ( β = 0.13 (0.04 to 0.21), P = 0.030), flight time longer ( β = -0.08 (-0.14 to -0.03), P < 0.001), and contact time ( β = 0.05 (-0.00 to 0.11), P = 0.001) shorter than with non-AFTs, but differences disappeared over time. CONCLUSIONS: There were no differences between shoe conditions in deterioration of RE during the 90-min run, but AFTs maintained their beneficial properties in RE over time and therefore are probably a good choice for long distances.