Author(s): SCHWALM, L., FOHRMANN, D., SCHAFFARCZYK, M., GRONWALD, T., HOLLANDER, K., Institution: MSH MEDICALSCHOOL HAMBURG, Country: GERMANY, Abstract-ID: 1543

INTRODUCTION:
Since the introduction of advanced footwear technologies (AFTs) in 2016, all world records from 5km to the marathon have been broken (1). This is due to an improved running economy (RE) with AFTs (2). To this date, these improvements have been investigated only during short running bouts, while there are indications that performance effects may be greater over longer distances (3). The aim of this study was to compare RE during a 90min run in AFTs compared to lightweight trainers (non-AFTs) in elite distance runners.
METHODS:
Nine elite distance runners visited our laboratory on two separate sessions within 14 days. In each session, they performed a submaximal threshold assessment treadmill test, followed by a 90min run below the first lactate threshold. Blood lactate concentration (BLa) as well as ratings of perceived exertion (RPE) were assessed every 15min. Mean V̇O2 determined during the last 3min of each 15min period was expressed as RE. We used linear mixed effects models (with random intercepts for participants) to examine the effects of time, shoe condition, and their interaction on energetic and oxygen cost of transport (ECOT and OCOT). Post hoc pairwise comparisons of estimated marginal means were performed using Tukey’s correction.
RESULTS:
The nine participants (55.6% females, age: 32.4±8.4y, body mass index: 20.8±1.2kg/m2) had a highest achieved world athletics score of 929.9±83.8 points which corresponds to 10km times of 30:17 and 36:09min for males and females, respectively. ECOT and OCOT were lower in AFTs (ECOT: 2.8±0.7%, p<0.001, β=0.56 [0.41 to 0.71]; OCOT: 1.9±0.9%, p<0.001, β=0.40 [0.26 to 0.55]). ECOT and OCOT increased over time (ECOT: p<0.001, β=0.40 [0.30 to 0.51]; OCOT: p<0.001, β=0.33 [0.23 to 0.44]) from minute 15 to 90 (ECOT: 6.1±3.7%; OCOT: 5.3±3.7%) but these changes did not differ between shoes (time x shoe interaction: ECOT: p=0.809; OCOT: p=0.649). RPE was lower in AFTs up to 60min (p=0.007, β=0.40 [0.16 to 0.64]), while BLa did not differ between shoe conditions at any time point (p=0.908).
CONCLUSION:
Although the change of RE during the 90min run did not reveal statistical differences between shoe conditions, AFTs maintained their beneficial properties over time. The duration and intensity of the exercise may have been too small to reveal differences in RE deterioration between shoe conditions over time. Therefore, AFTs are probably a good choice for long distances, but future studies should investigate the effects of AFTs during more intense and even longer running.


References
1. Muniz-Pardos et al., Sports Med, 2021
2. Burns et al., Int J Sports Physiol Perform, 2024
3. Willwacher et al., Sports Med Open, 2024