The Influence of Pre-Training Muscle Size on Strength Gain: An Exploratory Analysis

Authors

  • William Hammert Department of Health, Exercise Science, and Recreation Management, Kevser Ermin Applied Physiology Laboratory, The University of Mississippi, University, MS, USA
  • Jun Seob Song Department of Counseling, Health, and Kinesiology. Texas A&M University-San Antonio, San Antonio, TX, USA https://orcid.org/0009-0008-9440-2217
  • Yujiro Yamada Department of Health, Exercise Science, and Recreation Management, Kevser Ermin Applied Physiology Laboratory, The University of Mississippi, University, MS, USA https://orcid.org/0000-0002-0761-3075
  • Ryo Kataoka Department of Health, Exercise Science, and Recreation Management, Kevser Ermin Applied Physiology Laboratory, The University of Mississippi, University, MS, USA
  • Anna Kang Department of Health, Exercise Science, and Recreation Management, Kevser Ermin Applied Physiology Laboratory, The University of Mississippi, University, MS, USA
  • Robert Sallberg Department of Health, Exercise Science, and Recreation Management, Kevser Ermin Applied Physiology Laboratory, The University of Mississippi, University, MS, USA
  • Emily Metcalf Department of Health, Exercise Science, and Recreation Management, Kevser Ermin Applied Physiology Laboratory, The University of Mississippi, University, MS, USA https://orcid.org/0009-0004-3714-9543
  • Jeremy Loenneke Department of Health, Exercise Science, and Recreation Management, Kevser Ermin Applied Physiology Laboratory, The University of Mississippi, University, MS, USA

DOI:

https://doi.org/10.47206/ijsc.v6i1.557

Keywords:

Hypertrophy, Strength, Resistance training, Muscle growth, One-repitition maximum

Abstract

Purpose: To investigate whether changes in maximal strength following resistance training were influenced by pre-training muscle thickness.
Methods: We retrospectively analyzed data from a between-subject study that measured elbow flexor muscle thickness and maximum strength before and after a 6-week study. A total of 122 untrained individuals, who were randomly assigned to 1 of 3 groups, were included in the analyses: (a) time-matched, non-exercise control; (b) dominant arm training; or (c) nondominant arm training. The two training groups performed thrice weekly unilateral elbow flexion exercise, starting with up to 5 heavy singles, followed by 4 sets of 8–12 repetitions to task failure.
Results: Increases in strength were observed for both dominant arm [b = 2.29 kg, 95% CI = (1.72, 2.87)] and the non-dominant [b = 2.86 kg, 95% CI = (2.33, 3.39) training groups compared to the time-matched non-exercise control group. However, this increase in strength did not depend upon baseline muscle size for either group. Follow-up mediation analyses suggested that muscle growth mediated changes in strength for the dominant arm but not the nondominant arm training group.
Conclusion: We hypothesized that individuals with larger muscles at baseline would have a greater propensity to increase strength compared to those with smaller muscles. However, the magnitude of strength change was not influenced by pre-training muscle thickness. Follow-up mediation analysis on muscle growth was equivocal.

 

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Published

2026-07-03

Issue

Vol. 6 No. 1 (2026): International Journal of Strength and Conditioning

Section

Articles

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Copyright (c) 2026 William Hammert, Jun Seob Song, Yujiro Yamada, Ryo Kataoka, Anna Kang, Robert Sallberg, Emily Metcalf, Jeremy Loenneke

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This work is licensed under a Creative Commons Attribution 4.0 International License.

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How to Cite

Hammert, William, Jun Seob Song, Yujiro Yamada, Ryo Kataoka, Anna Kang, Robert Sallberg, Emily Metcalf, and Jeremy Loenneke. 2026. “The Influence of Pre-Training Muscle Size on Strength Gain: An Exploratory Analysis”. International Journal of Strength and Conditioning 6 (1). https://doi.org/10.47206/ijsc.v6i1.557.