Variations in lower‑limb body composition asymmetry and leg length discrepancy by sex and training level, and their association with performance in recreational endurance runners: a cross‑sectional study
4 affiliations
- 1Department of Movement and Sport Sciences, Movement and Nutrition for Health and Performance (MOVE) Research Group, Faculty of Physical Education and Physiotherapy, Vrije Universiteit Brussel, Pleinlaan 2, Brussels, 1050 Belgium
- 2Department of Physiotherapy, Human Physiology and Sports Physiotherapy Research Group, Human Physiology and Anatomy, Faculty of Physical Education and Physiotherapy, Vrije Universiteit Brussel, Brussels, Belgium
- 3Brussels Human Robotics Research Center, Vrije Universiteit Brussel, Brussels, Belgium
- 4REVAL Rehabilitation Research Center, Faculty of Rehabilitation Sciences, Hasselt University, Diepenbeek, Belgium
Abstract
Background: Body composition plays a critical role in endurance running. While anthropometric characteristics have been incorporated into performance prediction models, potential inter-limb morphological asymmetries in lower-limb body composition remain largely unexplored. Therefore, this study aimed to (1) quantify lower-limb morphological asymmetry and examine differences across sex and training level, (2) compare running performance between low- and high-asymmetry groups using split analyses, and (3) investigate the link between lean mass (LM), bone mineral content (BMC) and fat mass (FM) asymmetry as well as structural leg length discrepancy (LLD), and running performance in healthy adult endurance runners with varying training backgrounds.
Methods: Sixty-eight healthy adult recreational runners (53% male) were stratified by sex and training level (novice, intermediate, trained). Segmental lower-limb body composition (LM, bone mineral density (BMD), BMC, and FM) was assessed using dual-energy X-ray absorptiometry (DXA). Leg length was determined anthropometrically as the distance between the anterior superior iliac spine and medial malleolus. Running performance was evaluated using the Cooper 12-minute run test. Low and high asymmetry groups were created by categorizing participants according to the sample median asymmetry values for each outcome measure. Group differences were assessed using t-tests and ANOVAs, and multiple linear regression examined predictors of running performance.
Results: Mean asymmetry magnitudes ranged from 1.91% to 4.04% across metrics. Mean LLD ranged from 0.5 to 0.9 cm. Female runners demonstrated greater LLD than males (p = 0.004), and trained runners showed greater BMD asymmetry than novices (p = 0.006). LM, BMC and FM asymmetry as well as LLD were no significant predictors of Cooper test performance (p = 0.316 to 0.686). Furthermore, no significant differences were found between the low and high asymmetry groups (p = 0.379 to 0.999).
Conclusion: DXA-derived inter-limb asymmetries at lower limb level and LLD in recreational endurance runners are small and largely independent of sex and training level. Importantly, these asymmetries are not linked to running performance, suggesting limited practical relevance for performance optimization.
Trial registration: ClinicalTrials.gov (NCT06808399). Registered on 02 April 2025.
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BibTeX
@article{dhondt2026variations,
title = {{Variations in lower‑limb body composition asymmetry and leg length discrepancy by sex and training level, and their association with performance in recreational endurance runners: a cross‑sectional study}},
author = {Joachim D’Hondt and Eva D’Hondt and Dirk Aerenhouts and Kevin De Pauw and Peter Clarys and Laurent Chapelle},
journal = {BMC Sports Science, Medicine and Rehabilitation},
year = {2026},
month = aug,
doi = {10.1186/s13102-026-01952-x},
url = {https://doi.org/10.1186/s13102-026-01952-x},
note = {CC BY-NC-ND 4.0},
}
RIS
TY - JOUR
TI - Variations in lower‑limb body composition asymmetry and leg length discrepancy by sex and training level, and their association with performance in recreational endurance runners: a cross‑sectional study
AU - Joachim D’Hondt
AU - Eva D’Hondt
AU - Dirk Aerenhouts
AU - Kevin De Pauw
AU - Peter Clarys
AU - Laurent Chapelle
PY - 2026
DA - 2026/08/08
JO - BMC Sports Science, Medicine and Rehabilitation
DO - 10.1186/s13102-026-01952-x
UR - https://doi.org/10.1186/s13102-026-01952-x
AB - Background: Body composition plays a critical role in endurance running. While anthropometric characteristics have been incorporated into performance prediction models, potential inter-limb morphological asymmetries in lower-limb body composition remain largely unexplored. Therefore, this study aimed to (1) quantify lower-limb morphological asymmetry and examine differences across sex and training level, (2) compare running performance between low- and high-asymmetry groups using split analyses, and (3) investigate the link between lean mass (LM), bone mineral content (BMC) and fat mass (FM) asymmetry as well as structural leg length discrepancy (LLD), and running performance in healthy adult endurance runners with varying training backgrounds. Methods: Sixty-eight healthy adult recreational runners (53% male) were stratified by sex and training level (novice, intermediate, trained). Segmental lower-limb body composition (LM, bone mineral density (BMD), BMC, and FM) was assessed using dual-energy X-ray absorptiometry (DXA). Leg length was determined anthropometrically as the distance between the anterior superior iliac spine and medial malleolus. Running performance was evaluated using the Cooper 12-minute run test. Low and high asymmetry groups were created by categorizing participants according to the sample median asymmetry values for each outcome measure. Group differences were assessed using t-tests and ANOVAs, and multiple linear regression examined predictors of running performance. Results: Mean asymmetry magnitudes ranged from 1.91% to 4.04% across metrics. Mean LLD ranged from 0.5 to 0.9 cm. Female runners demonstrated greater LLD than males (p = 0.004), and trained runners showed greater BMD asymmetry than novices (p = 0.006). LM, BMC and FM asymmetry as well as LLD were no significant predictors of Cooper test performance (p = 0.316 to 0.686). Furthermore, no significant differences were found between the low and high asymmetry groups (p = 0.379 to 0.999). Conclusion: DXA-derived inter-limb asymmetries at lower limb level and LLD in recreational endurance runners are small and largely independent of sex and training level. Importantly, these asymmetries are not linked to running performance, suggesting limited practical relevance for performance optimization. Trial registration: ClinicalTrials.gov (NCT06808399). Registered on 02 April 2025.
SN - 2052-1847
ER -