Schoenfeld Brad J, Grgic Jozo, Haun Cody, Itagaki Takahiro, Helms Eric R
Health Sciences Department, City University of New York, Lehman College, Bronx, NY 10468, USA.
Institute for Health and Sport (IHES), Victoria University, Melbourne 3011, Australia.
Sports (Basel). 2019 Jul 22;7(7):177. doi: 10.3390/sports7070177.
Resistance training volume, determined by the number of sets performed (set-volume) is considered one of the key variables in promoting muscle hypertrophy. To better guide resistance exercise prescription for weekly per-muscle training volume, the purpose of this paper is to provide evidence-based considerations for set-volume ratios between multi-joint (MJ) and single-joint (SJ) exercises so that practitioners can better manage prescription of training volume in program design. We analyzed this topic from three primary areas of focus: (1) biomechanical and physiological factors; (2) acute research; and (3) longitudinal research. From a biomechanical and physiological standpoint, when considering force production of different muscle groups, the moment arm of a given muscle, "motor abundance", the link between biomechanics and exercise-induced fatigue, as well as the amount of time in voluntary muscle activation, a logical rationale can be made for SJ exercises producing greater hypertrophy of the limb muscles than MJ exercises (at least from specific exercises and under certain conditions). This would mean that sets for a MJ exercise should be counted fractionally for select muscles compared to an SJ exercise (i.e., less than a 1:1 ratio) when prescribing set-volumes for given muscles. When considering results from acute studies that measured muscle activation during the performance of SJ and MJ exercises, it seems that MJ exercises are not sufficient to maximize muscle activation of specific muscles. For example, during performance of the leg press and squat, muscle activation of the hamstrings is markedly lower than that of the quadriceps. These results suggest that a 1:1 ratio cannot be assumed. Current longitudinal research comparing the effects of training with MJ vs. SJ or MJ + SJ exercises is limited to the elbow flexors and the evidence is somewhat conflicting. Until more research is conducted to derive stronger conclusions on the topic, we propose the best advice would be to view set-volume prescription on a 1:1 basis, and then use logical rationale and personal expertise to make determinations on program design. Future research should focus on investigating longitudinal hypertrophic changes between MJ and SJ in a variety of populations, particularly resistance-trained individuals, while using site-specific measures of muscle growth to more systematically and precisely compute effective individualized set-volumes.
由所进行的组数决定的抗阻训练量（组次数）被认为是促进肌肉肥大的关键变量之一。为了更好地指导每周每块肌肉训练量的抗阻运动处方，本文旨在为多关节（MJ）和单关节（SJ）运动之间的组次数比例提供基于证据的考量，以便从业者在制定训练计划时能够更好地管理训练量的处方。我们从三个主要关注领域分析了这个主题：（1）生物力学和生理因素；（2）急性研究；（3）纵向研究。从生物力学和生理学的角度来看，在考虑不同肌肉群的力量产生时，特定肌肉的力臂、“运动丰富度”、生物力学与运动诱导疲劳之间的联系以及自主肌肉激活的时间量，可以得出一个合理的理由，即SJ运动比MJ运动能使肢体肌肉产生更大的肥大（至少在特定运动和某些条件下）。这意味着在为特定肌肉规定组次数时，与SJ运动相比，MJ运动的组数对于某些选定肌肉应按比例计算（即小于1:1的比例）。当考虑在SJ和MJ运动过程中测量肌肉激活的急性研究结果时，MJ运动似乎不足以使特定肌肉的肌肉激活最大化。例如，在进行腿举和深蹲时，腘绳肌的肌肉激活明显低于股四头肌。这些结果表明不能假定为1:1的比例。目前比较MJ与SJ或MJ + SJ运动训练效果的纵向研究仅限于肘屈肌，且证据有些相互矛盾。在进行更多研究以就该主题得出更强有力的结论之前，我们建议最好的建议是按1:1的基础看待组次数处方，然后运用合理的理由和个人专业知识来进行训练计划的确定。未来的研究应侧重于调查不同人群，特别是抗阻训练个体中MJ和SJ之间的纵向肥大变化，同时使用特定部位的肌肉生长测量方法，更系统、精确地计算有效的个体化组次数。
