Author(s): SCHWALM, L., MAI, J., FOHRMANN, D., SCHAFFARCZYK, M., MENGE, C., RÜCKEMANN, L., GRONWALD, T., HOLLANDER, K., Institution: MSH MEDICALSCHOOL HAMBURG, Country: GERMANY, Abstract-ID: 2227

INTRODUCTION:
Advanced footwear technology (AFT) is associated with improved running economy (RE) compared to traditional footwear and has been attributed to the rapid improvement in running performances. Current research has focused on quantifying acute RE benefits across AFT and during different run durations. In contrast, this 12-week longitudinal randomized controlled trial provides novel evidence on the effects of regular AFT training on RE.
METHODS:
A total of 70 trained long-distance runners participated in this randomized controlled trial with a parallel group trial design and 1:1 allocation ratio. The participants visited our laboratory before and after a 12-week intervention period. On the first laboratory visit (PRE), they completed 6x5min running trials at standardized submaximal speeds (f: 12km/h; m: 14km/h) in three different shoe conditions (two trials per shoe in a randomized order): 1. a AFT (L_AFT), 2. a NonAFT (L_nAFT), and 3. depending on the group allocation, an identical model of the AFT (I_AFT, for the intervention group) or NonAFT (I_nAFT, for the control group). L_AFT and L_nAFT remained in the laboratory for the second visit (POST), whereas the third shoe was provided to the participants for the intervention. During the 12-week intervention period, the participants continued their habitual training while gradually increasing the percentage of mileage in the provided shoe. Afterwards the participants completed the same laboratory test again. Breath-by-breath pulmonary gas exchange was recorded during the 5min trials and the mean V̇O2 determined during the last 3min was analyzed. We used linear mixed-effects models with random intercepts for participants and calculated estimated marginal means to examine the effects of time (PRE/POST), shoe condition (L_AFT/L_nAFT), group allocation and their interactions on energetic cost of transport (ECOT) while controlling for sex and trial order as covariates.
RESULTS:
This analysis included 60 participants (45.0% female; 32.4 ± 8.2years; body mass index: 22.3 ± 2.2kg·m-2). The dropout rate was 14.3% (three participants in the AFT group and seven in the NonAFT group were lost to follow-up). The three-way interaction of group × time × shoe condition was not significant (estimate = 0.017J·kg⁻¹·m⁻¹, 95% CI [-0.087, 0.120], p = .751), providing no evidence that the 12-week habituation moderated the energetic benefit of AFT shoes. L_AFT shoes reduced ECOT compared to L_nAFT shoes across groups and visits (differences ranging from 2.5 to 3.2%, all p ≤ .001). No significant effects of time or group allocation were observed.
CONCLUSION:
Regular training in and habituation to AFT does not change their benefits in RE. This suggests that regular AFT training is neither necessary nor detrimental in terms of RE benefits. Additionally, runners can save money by training in cheaper traditional running shoes, while keeping in mind other potential distinct implementation, familiarization, and adaptation processes associated with AFT usage.