# Sex and Isolated Anthropometric Measures Do Not Explain Individual Differences in Responsiveness to Advanced Footwear Technology in Highly Trained Runners

## TL;DR

This study found that sex and body measurements do not explain why some runners benefit more from advanced running shoes than others.

## Contribution

The study shows that neither sex nor isolated anthropometric traits predict individual differences in responsiveness to advanced footwear technology.

## Key findings

- Females had lower energy cost than males, but there was no sex difference in ΔEC.
- Individual ΔEC varied widely, from 1.1% to 8.7%.
- Anthropometric variables could not predict ΔEC in either sex.

## Abstract

Advanced footwear technology (AFT) has improved running economy in distance runners, yet individual responsiveness varies widely. Sex differences and anthropometric characteristics have been proposed as potential factors, but evidence remains limited. This study investigated whether sex‐based differences exist in the response to running in an AFT shoe compared to a non‐AFT control shoe. The response was measured by means of the change in energy cost (EC), ΔEC, and it was assessed whether isolated anthropometric characteristics could predict ΔEC in highly trained long‐distance runners. Fifteen female and fifteen male runners completed treadmill running economy tests at 60%, 70%, and 80% of their VO2peak speed in AFT and non‐AFT shoes. Anthropometric measures investigated were height, body mass, foot length, femur and tibia length, and Achilles tendon length. Females showed significantly lower absolute EC than males across all speeds and shoe conditions (p < 0.05), but ΔEC did not differ between sexes (p = 0.5). Average individual ΔEC ranged from 1.1% to 6.4% in females and 0.2% to 8.7% in males. No anthropometric variable could significantly predict ΔEC in sex‐stratified analyses. Highly trained runners exhibit large inter‐individual variability in responsiveness to AFT shoes, but neither sex nor isolated anthropometric traits explained these differences in this study. These findings highlight the complexity of AFT individualization and suggest that personalization should not be based solely on sex or the anthropometric characteristics investigated in this study.