Improving Running Economy by Transitioning to Minimalist Footwear: A Randomised Controlled Trial

Objectives: Ongoing debates about benefits and risks of barefoot- and minimally-shod running have, to date, revealed no conclusive findings for long-term effects on physical performance. The purpose of this study was to examine the effects of an 8-week transition to minimalist footwear (MFW) on running economy (RE). Design: Randomised controlled trial. Methods: Thirty-two male, habitually-shod runners were assigned randomly to an 8-week training intervention either in minimalist (=intervention group) or conventional running shoes (=control group). The intervention consisted of a gradual increase in use of the new footwear by 5% of the individual weekly distance. Before and after the intervention, a VO(2)max test was followed by a submaximal RE test at 70% and 80% of vVO(2)max in both shoe conditions 7 days later. RE was measured at the submaximal tests and expressed as caloric unit cost (kcal kg(-3) km(-1)) and oxygen consumption (ml kg(-1) km(-1)). Results: RE improved in the intervention group over time compared to the control group with small to moderate effect sizes (ES) in both shoe conditions: Effects on RE (kcal kg(-1 )km(-1)) in conventional running shoes: ES vVO(2) 70%: 0.68 (95% CI: -0.14 to 1.51), ES vVO(2) 80%: 0.78 (95% CI: 0-1.56). In minimalist footwear: ES vVO(2) 70%: 0.3 (95% CI: -0.54 to 1.14), ES vVO(2) 80%: 0.42 (95% CI: -0.41 to 1.25). These effects were not statistically significant (p > 0.05). The repeated-measures ANOVA also showed no group by time interactions for all submaximal RE testing conditions (p > 0.05). Conclusions: Although not reaching statistical significance, training in MEW compared to CRS resulted in small to moderate improvements in RE. (C) 2018 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.