Methods matter: the relationship between strength and hypertrophy depends on methods of measurement and analysis
Purpose The relationship between changes in muscle size and strength may be affected by both measurement and statistical approaches, but their effects have not been fully considered or quantified. Therefore, the purpose of this investigation was to explore how different methods of measurement and an...
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| Format: | Article |
| Language: | English |
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PeerJ Inc.
2018-06-01
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| Series: | PeerJ |
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| Online Access: | https://peerj.com/articles/5071.pdf |
| _version_ | 1827606148986961920 |
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| author | Andrew D. Vigotsky Brad J. Schoenfeld Christian Than J. Mark Brown |
| author_facet | Andrew D. Vigotsky Brad J. Schoenfeld Christian Than J. Mark Brown |
| author_sort | Andrew D. Vigotsky |
| collection | DOAJ |
| description | Purpose The relationship between changes in muscle size and strength may be affected by both measurement and statistical approaches, but their effects have not been fully considered or quantified. Therefore, the purpose of this investigation was to explore how different methods of measurement and analysis can affect inferences surrounding the relationship between hypertrophy and strength gain. Methods Data from a previous study—in which participants performed eight weeks of elbow flexor training, followed by an eight-week period of detraining—were reanalyzed using different statistical models, including standard between-subject correlations, analysis of covariance, and hierarchical linear modeling. Results The associative relationship between strength and hypertrophy is highly dependent upon both method/site of measurement and analysis; large differences in variance accounted for (VAF) by the statistical models were observed (VAF = 0–24.1%). Different sites and measurements of muscle size showed a range of correlations coefficients with one another (r = 0.326–0.945). Finally, exploratory analyses revealed moderate-to-strong relationships between within-individual strength-hypertrophy relationships and strength gained over the training period (ρ = 0.36–0.55). Conclusions Methods of measurement and analysis greatly influence the conclusions that may be drawn from a given dataset. Analyses that do not account for inter-individual differences may underestimate the relationship between hypertrophy and strength gain, and different methods of assessing muscle size will produce different results. It is suggested that robust experimental designs and analysis techniques, which control for different mechanistic sources of strength gain and inter-individual differences (e.g., muscle moment arms, muscle architecture, activation, and normalized muscle force), be employed in future investigations. |
| first_indexed | 2024-03-09T06:34:06Z |
| format | Article |
| id | doaj.art-504a71f657374557bedfcc0ac343db83 |
| institution | Directory Open Access Journal |
| issn | 2167-8359 |
| language | English |
| last_indexed | 2024-03-09T06:34:06Z |
| publishDate | 2018-06-01 |
| publisher | PeerJ Inc. |
| record_format | Article |
| series | PeerJ |
| spelling | doaj.art-504a71f657374557bedfcc0ac343db832023-12-03T11:01:19ZengPeerJ Inc.PeerJ2167-83592018-06-016e507110.7717/peerj.5071Methods matter: the relationship between strength and hypertrophy depends on methods of measurement and analysisAndrew D. Vigotsky0Brad J. Schoenfeld1Christian Than2J. Mark Brown3Department of Biomedical Engineering, Northwestern University, Evanston, IL, United States of AmericaDepartment of Health Sciences, City University of New York, Herbert H. Lehman College, Bronx, NY, United States of AmericaSchool of Biomedical Sciences, University of Queensland, St. Lucia, Queensland, AustraliaSchool of Biomedical Sciences, University of Queensland, St. Lucia, Queensland, AustraliaPurpose The relationship between changes in muscle size and strength may be affected by both measurement and statistical approaches, but their effects have not been fully considered or quantified. Therefore, the purpose of this investigation was to explore how different methods of measurement and analysis can affect inferences surrounding the relationship between hypertrophy and strength gain. Methods Data from a previous study—in which participants performed eight weeks of elbow flexor training, followed by an eight-week period of detraining—were reanalyzed using different statistical models, including standard between-subject correlations, analysis of covariance, and hierarchical linear modeling. Results The associative relationship between strength and hypertrophy is highly dependent upon both method/site of measurement and analysis; large differences in variance accounted for (VAF) by the statistical models were observed (VAF = 0–24.1%). Different sites and measurements of muscle size showed a range of correlations coefficients with one another (r = 0.326–0.945). Finally, exploratory analyses revealed moderate-to-strong relationships between within-individual strength-hypertrophy relationships and strength gained over the training period (ρ = 0.36–0.55). Conclusions Methods of measurement and analysis greatly influence the conclusions that may be drawn from a given dataset. Analyses that do not account for inter-individual differences may underestimate the relationship between hypertrophy and strength gain, and different methods of assessing muscle size will produce different results. It is suggested that robust experimental designs and analysis techniques, which control for different mechanistic sources of strength gain and inter-individual differences (e.g., muscle moment arms, muscle architecture, activation, and normalized muscle force), be employed in future investigations.https://peerj.com/articles/5071.pdfHierarchical linear modelsRepeated measuresStrengthHypertrophyAnalysis of covarianceRegression |
| spellingShingle | Andrew D. Vigotsky Brad J. Schoenfeld Christian Than J. Mark Brown Methods matter: the relationship between strength and hypertrophy depends on methods of measurement and analysis PeerJ Hierarchical linear models Repeated measures Strength Hypertrophy Analysis of covariance Regression |
| title | Methods matter: the relationship between strength and hypertrophy depends on methods of measurement and analysis |
| title_full | Methods matter: the relationship between strength and hypertrophy depends on methods of measurement and analysis |
| title_fullStr | Methods matter: the relationship between strength and hypertrophy depends on methods of measurement and analysis |
| title_full_unstemmed | Methods matter: the relationship between strength and hypertrophy depends on methods of measurement and analysis |
| title_short | Methods matter: the relationship between strength and hypertrophy depends on methods of measurement and analysis |
| title_sort | methods matter the relationship between strength and hypertrophy depends on methods of measurement and analysis |
| topic | Hierarchical linear models Repeated measures Strength Hypertrophy Analysis of covariance Regression |
| url | https://peerj.com/articles/5071.pdf |
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