Muscle Activation During Power-Oriented Resistance Training: Continuous vs. Cluster Set Configurations

Abstract

Morales-Artacho, AJ, García-Ramos, A, Pérez-Castilla, A, Padial, P, Gomez, AM, Peinado, AM, Pérez-Córdoba, JL, and Feriche, B. Muscle activation during power-oriented resistance training: continuous vs. cluster set configurations. J Strength Cond Res 33(7S): S95–S102, 2019—This study examined performance and electromyography (EMG) changes during a power training protocol comprising continuous or clustered set configurations. Eighteen active males completed 6 sets of 6 repetitions during the loaded (20% 1 repetition maximum) countermovement jump (CMJ) exercise, continuously (n = 9) or with a 30-second pause every 2 repetitions (cluster; n = 9). Power output, vastus lateralis (VL), vastus medialis (VM), and rectus femoris (RF) EMG were recorded during all CMJs. Relative changes from the first repetition were assessed on the EMG root mean square (RMS), median frequency (Fmed), and a low- to high-frequency ratio index of fatigue (FInsmk). Greater power output decrements were observed during the continuous set configuration (p = 0.001, JOURNAL/jscr/04.03/00124278-201907001-00011/inline-formula1/v/2023-08-19T002824Z/r/image-tiff < 0.01). Greater RMS increments in VL (6.8 ± 11.3 vs. −1.7 ± 5.8%) and RF (9.3 ± 14.2 vs. 1.9 ± 6.9%), but not VM (2.0 ± 4.7 vs. 2.6 ± 7.3%), were also observed in the continuous compared with the cluster sets (p = 0.033, JOURNAL/jscr/04.03/00124278-201907001-00011/inline-formula2/v/2023-08-19T002824Z/r/image-tiff = 0.06). Progressive decrements in Fmed and increments in FInsmk were observed across repetitions in both set configurations. In conclusion, although clustering sets between repetitions clearly maintained power output, mixed responses were observed on the examined EMG parameters.

Acute Mechanical, Neuromuscular, and Metabolic Responses to Different Set Configurations in Resistance Training

“…Likewise, recording electromyography (EMG) activity (amplitude, through root mean square “RMS,” and frequency, through median frequency “MDF”) may provide a better understanding of the mechanisms behind the changes in mechanical performance, such as muscle activation and neuromuscular fatigue accumulated throughout the training session (6). To date, only one previous study has examined neuromuscular activity during different set configurations involving lower-body muscles (25), which compared 6 sets of 6 repetitions at 20% of 1 repetition maximum (1RM) in loaded jumps, continuously ( n = 9) or with a 30-second rest every 2 repetitions ( n = 9). These authors observed larger increments in RMS throughout longer set configurations; however, both protocols induced similar decrements in MDF (25).…”

“…To date, only one previous study has examined neuromuscular activity during different set configurations involving lower-body muscles (25), which compared 6 sets of 6 repetitions at 20% of 1 repetition maximum (1RM) in loaded jumps, continuously ( n = 9) or with a 30-second rest every 2 repetitions ( n = 9). These authors observed larger increments in RMS throughout longer set configurations; however, both protocols induced similar decrements in MDF (25). However, the fact that different subjects performed each protocol may have obscured potential differences in the EMG spectral parameters between protocols.…”

Effects of Cluster Set Configuration on Mechanical Performance and Neuromuscular Activity

“…In this regard, monitoring the electromyography (EMG) activity attained in each repetition may provide better knowledge about the muscle excitation and neuromuscular fatigue accumulated throughout the training session (44). To the best of our knowledge, only one study has investigated the effect of CS configuration on EMG activity (27), by comparing 6 sets of 6 repetitions at 20% of 1RM in the loaded countermovement jump (CMJ) exercise, continuously or with a 30-second pause every 2 repetitions (27). These authors observed a greater root mean square (RMS) in the vastus lateralis and rectus femoris muscles, but not in the vastus medialis, during the TRD configuration compared with a CS, along with progressive decrements in median frequency (MDF) without differences between set configurations (27).…”

“…To the best of our knowledge, only one study has investigated the effect of CS configuration on EMG activity (27), by comparing 6 sets of 6 repetitions at 20% of 1RM in the loaded countermovement jump (CMJ) exercise, continuously or with a 30-second pause every 2 repetitions (27). These authors observed a greater root mean square (RMS) in the vastus lateralis and rectus femoris muscles, but not in the vastus medialis, during the TRD configuration compared with a CS, along with progressive decrements in median frequency (MDF) without differences between set configurations (27). Likewise, the CMJ exercise involves both eccentric and concentric muscle actions, whereas the CS approach is mainly used to maintain acute concentric exercise performance (39).…”

Inertial Sensor Location for Ground Reaction Force and Gait Event Detection Using Reservoir Computing in Gait

“…Participants self-selected their walking speed (SS) during a five-minute trial on the instrumented treadmill (Bertec, Columbus, OH, USA, 1000 Hz). Based on a previously established cross-correlation approach, the measured signals (IMUs and GRF) were synchronized in pre-processing [ 46 ]. The walking at three speeds was recorded: SS, 20% faster and slower than SS.…”