Lacio Marcio, Vieira João Guilherme, Trybulski Robert, Campos Yuri, Santana Derick, Filho José Elias, Novaes Jefferson, Vianna Jeferson, Wilk Michal
Postgraduate Program in Physical Education, Federal University of Juiz de Fora (UFJF), Juiz de Fora 36036-900, Brazil.
Strength Training Research Laboratory, Federal University of Juiz de Fora (UFJF), Juiz de Fora 36036-900, Brazil.
Int J Environ Res Public Health. 2021 Oct 26;18(21):11237. doi: 10.3390/ijerph182111237.
The load in resistance training is considered to be a critical variable for neuromuscular adaptations. Therefore, it is important to assess the effects of applying different loads on the development of maximal strength and muscular hypertrophy. The aim of this study was to systematically review the literature and compare the effects of resistance training that was performed with low loads versus moderate and high loads in untrained and trained healthy adult males on the development of maximal strength and muscle hypertrophy during randomized experimental designs. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines (2021) were followed with the eligibility criteria defined according to participants, interventions, comparators, outcomes, and study design (PICOS): (P) healthy males between 18 and 40 years old, (I) interventions performed with low loads, (C) interventions performed with moderate or high loads, (O) development of maximal strength and muscle hypertrophy, and (S) randomized experimental studies with between- or within-subject parallel designs. The literature search strategy was performed in three electronic databases (Embase, PubMed, and Web of Science) on 22 August 2021. Twenty-three studies with a total of 563 participants (80.6% untrained and 19.4% trained) were selected. The studies included both relative and absolute loads. All studies were classified as being moderate-to-high methodological quality, although only two studies had a score higher than six points. The main findings indicated that the load magnitude that was used during resistance training influenced the dynamic strength and isometric strength gains. In general, comparisons between the groups (i.e., low, moderate, and high loads) showed higher gains in 1RM and maximal voluntary isometric contraction when moderate and high loads were used. In contrast, regarding muscle hypertrophy, most studies showed that when resistance training was performed to muscle failure, the load used had less influence on muscle hypertrophy. The current literature shows that gains in maximal strength are more pronounced with high and moderate loads compared to low loads in healthy adult male populations. However, for muscle hypertrophy, studies indicate that a wide spectrum of loads (i.e., 30 to 90% 1RM) may be used for healthy adult male populations.
抗阻训练中的负荷被认为是神经肌肉适应的一个关键变量。因此，评估施加不同负荷对最大力量发展和肌肉肥大的影响非常重要。本研究的目的是系统回顾文献，并比较在随机实验设计中，未经训练和受过训练的健康成年男性进行低负荷与中、高负荷抗阻训练对最大力量发展和肌肉肥大的影响。本研究遵循系统评价和荟萃分析的首选报告项目指南（2021年），根据参与者、干预措施、对照、结局和研究设计（PICOS）定义纳入标准：（P）18至40岁的健康男性，（I）低负荷干预，（C）中、高负荷干预，（O）最大力量发展和肌肉肥大，（S）受试者间或受试者内平行设计的随机实验研究。2021年8月22日在三个电子数据库（Embase、PubMed和Web of Science）中进行了文献检索策略。共筛选出23项研究，涉及563名参与者（80.6%未经训练，19.4%受过训练）。这些研究包括相对负荷和绝对负荷。所有研究的方法学质量均被归类为中到高，尽管只有两项研究得分高于6分。主要研究结果表明，抗阻训练期间使用的负荷大小会影响动态力量和等长力量的增加。总体而言，组间比较（即低、中、高负荷）显示，使用中、高负荷时，1RM和最大随意等长收缩的增加幅度更大。相比之下，关于肌肉肥大，大多数研究表明，当抗阻训练进行到肌肉疲劳时，使用的负荷对肌肉肥大的影响较小。当前文献表明，在健康成年男性群体中，与低负荷相比，高负荷和中负荷时最大力量的增加更为明显。然而，对于肌肉肥大，研究表明，健康成年男性群体可使用广泛范围的负荷（即1RM的30%至90%）。
