Sex differences in three-dimensional intra-cycle velocity fluctuation and performance during freestyle swimming among high-level swimmers.

Zhenyu Jin, Yulin Zhou, Yuhang Zhou, Qian Yu, Dapeng Wang, Sijia Shen, Yuhong Wen

Abstract read

In one paragraph

Article in Scientific reports, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

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0 citing papers in PubMed.

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4 · The record

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5 · Who and what money

Authors and funding

7 authors.

Zhenyu JinSchool of Sports, Leisure and Tourism, Beijing Sport University, 48 XinxiRoad, Haidian District, Beijing, 100084, China.

Yulin ZhouCollege of Sports Science, Beijing Sport University, Beijing, 100084, China.

Yuhang ZhouKey laboratory of Sport Training of General Administration of Sport of China, Beijing, 100084, China.

Qian YuPhysical Education and Research Department, Peking University, Beijing, 100871, China.

Dapeng WangKey laboratory of Sport Training of General Administration of Sport of China, Beijing, 100084, China.

Sijia ShenKey laboratory of Sport Training of General Administration of Sport of China, Beijing, 100084, China.

Yuhong WenSchool of Sports, Leisure and Tourism, Beijing Sport University, 48 XinxiRoad, Haidian District, Beijing, 100084, China. wyhswim@126.com.

Funding

Fundamental Research Funds for the Central Universities 2024YDXL003

6 · The paper itself

Abstract

This study examined sex differences in three-dimensional intra-cycle velocity fluctuations (IVFs) of the body's center of mass and the relationship between IVFs and swimming velocity (Vswim) in high-level swimmers during freestyle. Maximal-effort freestyle sprints performed by 13 high-level athletes (7 males and 6 females) were captured using a Qualisys three-dimensional motion capture system. Given the limited sample size, robust statistical approaches, including Welch's t-tests, Bayesian analyses, and permutation tests were applied. Male swimmers exhibited significantly higher Vswim (p < 0.001, ES = 2.94), forward IVF (p < 0.001, ES = 2.47), and vertical IVF (p = 0.022, ES = 1.57) compared with female swimmers. Bayesian analysis of interaction terms revealed no statistically significant moderating effect of sex on the relationship between IVF and Vswim. These findings indicate that although clear sex differences are evident in specific IVF components and swimming speed among high-level swimmers, the functional relationship between IVF and performance remains statistically consistent across sexes. From a practical perspective, IVF-based interventions should integrate sex-related physiological characteristics with individualized technical profiling to avoid overgeneralization. This study also establishes a high-fidelity methodological reference for three-dimensional kinematic analysis, providing a valuable dataset for future research and technological validation.

Indexed as

Athletic PerformanceSex CharacteristicsSwimmingAthletesBayes TheoremBiomechanical PhenomenaFemaleHumansMaleYoung Adult3D motion captureFreestyleHigh-level swimmersIntra-cycle velocity fluctuationSex differences

Identifiers

PMID42056305

DOI10.1038/s41598-026-48979-1

PMCPMC13319195

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LicenceCC BY

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.