Biology subjects

Healey, L.

Publications and source records attributed to Healey, L..

3 recordsLinked to original sources

bioRxiv2026

Supershoes or Superhumans? A controlled analysis of sex-specific road-running performance evolution in the era of advanced footwear technology

Advanced footwear technology (AFT) improves running economy and is widely credited with recent performance improvements in road running, with observational analyses consistently demonstrating that women have improved more than men. In contrast, laboratory studies generally report similar running economy responses to AFT in both sexes, leaving the observational-experimental divergence unresolved. A fundamental limitation of observational work is the absence of a control condition, making it impossible to separate AFT-related gains from concurrent performance trends. We addressed this by comparing performances between pre-AFT (2009-2015) and AFT (2017-2024) eras across road-running events (10km, half marathon, marathon) and throwing events (shot put, discus, javelin, hammer), the latter serving as an active control condition subject to the same broad athletic trends but unaffected by footwear technology. The top 50 performances per event, era, and sex were converted to World Athletics points and analysed using linear mixed-effects models. Performances improved significantly between eras ({beta} = 0.294, p < .001), with gains substantially larger in road running than in throwing ({beta} = 0.731, p < .001). The sex-specific pattern of improvement also differed between event categories (era x event type x sex interaction, {beta} = 0.786, p < .001): road-running improvements were greater in women than men (4.51% vs 2.62%), whereas throwing improvements did not differ by sex (0.93% vs 1.14%). These findings suggest that AFT benefits women more than men in competition, whether through a greater physiological response or more effective translation of economy gains to race performance, and suggest current laboratory protocols may be insufficiently sensitive to detect potential sex-specific effects.

physiology↗

bioRxiv2025

Data driven shoe design improves running economy beyond state-of-the-art Advanced Footwear Technology running shoes

Advanced Footwear Technology (AFT) has enabled remarkable improvements in running performance over traditional marathon racing shoes. However, reported differences between state-of-the-art AFT models are small, and vary across individuals. To assess if the benefits of AFT have been fully realized or if further running economy improvements can be unlocked using modern computational design and optimization techniques, we compared a prototype AFT shoe developed using a data-driven computational design process (PUMA Fast-R 3; FR3) against state-of-the-art AFT models. We quantified running economy for 15 trained runners (11M, 4F) in this prototype AFT shoe and three commercially available AFT models: the PUMA Fast-R 2 (FR2), the Nike Alphafly 3 (NIKE), and the Adidas Adios Pro Evo (ADI). Running economy in the FR3 was 3.15 {+/-} 1.24%, 3.62 {+/-} 1.25%, and 3.54 {+/-} 1.16% better than in the FR2, NIKE and ADI (all p < 0.001), respectively, and every individual performed best in the FR3 shoes. While step parameters were similar between FR3 and FR2, the FR3 had a lower step frequency than the ADI (p = 0.013) and longer contact time than the NIKE and ADI (both p<0.001). Our results suggest that computational design analysis is a promising frontier in performance running shoe design, offering potential for further improvements and personalized AFT models.

physiology↗

bioRxiv2025

Is increasing the effective leg length of a human runner metabolically beneficial?

The purpose of this study was to understand if footwear midsole thickness can decrease the metabolic cost of running by increasing the effective leg length of a runner. We also sought to understand the role of midsole compliance on these measures. Participants (n = 16) ran on a treadmill at 14 km h-1 in four mass-matched shoe conditions: 30, 40, and 60 mm thickness of a firm midsole foam and 60 mm thickness of a compliant midsole foam. Over two testing sessions, we measured metabolic cost (two 5-minute trials in each condition) and biomechanical measures (one 2-minute trial in each condition). Increasing thickness in the firm midsole conditions increased effective leg length during early, mid, and late stance (all p < 0.001). However, metabolic cost increased (p = 0.031). Changing material from firm to compliant decreased effective leg length during midstance (p < 0.001), but not during early or late stance, and decreased metabolic cost (p < 0.001). Results suggest that increasing midsole thickness can increase the effective leg length of a runner, but this isolated effect leads to increasing in metabolic cost. On the other hand, increasing midsole compliance leads to reductions in metabolic cost, agreeing with previous literature. We suggest that the performance benefits seen in advanced footwear technology with increased midsole thickness are likely due to increased capacity to return mechanical energy, not due increases in effective leg length. Summary StatementIncreased midsole compliance, not increased effective leg length, is responsible for decreased metabolic cost in running.

physiology↗