Human Performance and Sports Science Laboratory, Faculty of Sport Sciences, University of Murcia, Murcia, SPAIN.
Med Sci Sports Exerc. 2023 Dec 1;55(12):2316-2327. doi: 10.1249/MSS.0000000000003271. Epub 2023 Aug 2.
This study aimed to compare the effects of free-weight and machine-based resistance training on strength, hypertrophy, and joint discomfort.
Thirty-eight resistance-trained men participated in an 8-wk resistance program allocated into free-weight ( n = 19) or machine-based ( n = 19) groups. Training variables were identical for both modalities, so they only differed in the use of barbells or machines to execute the full squat, bench press, prone bench pull, and shoulder press exercises. The velocity-based method was implemented to accurately adjust the intensity throughout the program. Strength changes were evaluated using eight velocity-monitored loading tests (four exercises × two modalities) and included the relative one-repetition maximum (1RM Rel ), as well as the mean propulsive velocity against low (MPV Low ) and high (MPV High ) loads. Ultrasound-derived cross-sectional area of quadriceps (proximal and distal regions), pectoralis major, and rectus abdominis was measured to examine hypertrophy. Complementarily, Western Ontario and McMaster Universities and Disabilities of the Arm, Shoulder and Hand questionnaires were administrated to assess changes in lower- and upper-limb joint discomfort. Outcomes were compared using ANCOVA and percentage of change (∆) statistics.
Each group significantly ( P < 0.001) increased 1RM Rel , MPV Low , and MPV High for both modalities tested, but especially in the one they trained. When considering together the eight exercises tested, strength changes for both modalities were similar (∆ differences ≤1.8%, P ≥ 0.216). Likewise, the cross-sectional area of all the muscles evaluated was significantly increased by both modalities, with no significant differences between them (∆ difference ≤2.0%, P ≥ 0.208). No between-group differences ( P ≥ 0.144) were found for changes in stiffness, pain, and functional disability levels, which were reduced by both modalities.
Free-weight and machine-based modalities are similarly effective to promote strength and hypertrophy without increasing joint discomfort.
本研究旨在比较自由重量和基于器械的抗阻训练对力量、肥大和关节不适的影响。
38 名抗阻训练男性参与了为期 8 周的抗阻训练计划，分为自由重量（n=19）或基于器械（n=19）组。两种方式的训练变量相同，只是在执行全蹲、卧推、俯姿卧拉和肩推练习时使用杠铃或器械有所不同。采用速度法准确调整整个方案的强度。使用八项速度监测加载测试（四项练习×两种方式）评估力量变化，包括相对 1 次重复最大重量（1RM Rel），以及低（MPV Low）和高（MPV High）负荷下的平均推进速度。使用超声测量股四头肌（近端和远端区域）、胸大肌和腹直肌的横截面积，以检查肥大情况。此外，还使用安大略西部大学和麦克马斯特大学残疾问卷以及手臂、肩部和手残疾问卷评估上肢和下肢关节不适的变化。使用协方差分析和变化百分比（∆）统计比较结果。
每组在两种测试方式下的 1RM Rel、MPV Low 和 MPV High 均显著增加（P<0.001），但在他们训练的方式中增加更明显。当考虑到测试的八项练习时，两种方式的力量变化相似（∆差异≤1.8%，P≥0.216）。同样，两种方式均显著增加了所有评估肌肉的横截面积，且两者之间无显著差异（∆差异≤2.0%，P≥0.208）。两种方式对刚度、疼痛和功能障碍水平的变化均无显著差异（P≥0.144），且这些变化都有所降低。
自由重量和基于器械的方式均可有效促进力量和肥大，而不会增加关节不适。
