Vigotsky Andrew D, Schoenfeld Brad J, Than Christian, Brown J Mark
Department of Biomedical Engineering, Northwestern University, Evanston, IL, United States of America.
Department of Health Sciences, City University of New York, Herbert H. Lehman College, Bronx, NY, United States of America.
PeerJ. 2018 Jun 27;6:e5071. doi: 10.7717/peerj.5071. eCollection 2018.
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.
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.
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 ( = 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 ( = 0.36-0.55).
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.
肌肉大小变化与力量之间的关系可能会受到测量方法和统计方法的影响，但其影响尚未得到充分考虑或量化。因此，本研究的目的是探讨不同的测量和分析方法如何影响关于肥大与力量增加之间关系的推断。
对之前一项研究的数据进行重新分析，在该研究中，参与者进行了为期八周的肘部屈肌训练，随后是为期八周的停训期，使用了不同的统计模型，包括标准的组间相关性分析、协方差分析和分层线性建模。
力量与肥大之间的关联关系高度依赖于测量方法/部位和分析方法；观察到统计模型解释的方差（VAF）存在很大差异（VAF = 0 - 24.1%）。不同部位和肌肉大小测量值之间显示出一系列相互关联的系数（= 0.326 - 0.945）。最后，探索性分析揭示了个体内部力量 - 肥大关系与训练期间获得的力量之间存在中度至强的关系（= 0.36 - 0.55）。
测量和分析方法极大地影响了从给定数据集中得出的结论。不考虑个体间差异的分析可能会低估肥大与力量增加之间的关系，并且不同的评估肌肉大小的方法会产生不同的结果。建议在未来的研究中采用稳健的实验设计和分析技术，控制力量增加的不同机制来源和个体间差异（例如肌肉力臂、肌肉结构、激活和标准化肌肉力量）。
