Influence of Cluster Sets on Mechanical and Perceptual Variables in Adolescent Athletes

Abstract

Cluster sets (CS) are effective in maintaining performance and reducing perceived effort compared to traditional sets (TRD). However, little is known about these effects on adolescent athletes. The purpose of this study was to compare the effect of CS on the performance of mechanical and perceptual variables in young athletes. Eleven subjects [4 boys (age = 15.5 ± 0.8 years; body mass = 54.3 ± 7.0 kg; body height = 1.67 ± 0.04 m; Back Squat 1RM/body mass: 1.62 ± 0.19 kg; years from peak height velocity [PHV]: 0.94 ± 0.50) and 7 girls (age = 17.2 ± 1.4 years; body mass = 54.7 ± 6.3 kg; body height = 1.63 ± 0.08 m; Back Squat 1RM/body mass: 1.22 ± 0.16 kg; years from PHV: 3.33 ± 1.00)] participated in a randomized crossover design with one traditional (TRD: 3 × 8, no intra-set and 225 s interest rest) and two clusters (CS1: 3 × 2 × 4, one 30 s intra-set and 180 s inter-set rest; and CS2: 3 × 4 × 2, three 30 s intra-set and 90 s inter-set rest) protocols. The subjects were assessed for a Back Squat 1RM for the first meet, then performed the three protocols on three different days, with at least 48 h between them. During experimental sessions, a back squat exercise was performed, and mean propulsive velocity (MPV), power (MPP), and force (MPF) were collected to analyze performance between protocols, together with measures of countermovement jump (CMJ) and perceptual responses through Rating of Perceived Exertion for each set (RPE-Set) and the overall session (S-RPE), and Muscle Soreness (DOMS). The results showed that velocity and power decline (MVD and MPD) were favorable for CS2 (MVD: −5.61 ± 14.84%; MPD: −5.63 ± 14.91%) against TRD (MVD: −21.10 ± 11.88%; MPD: −20.98 ± 11.85%) (p < 0.01) and CS1 (MVD: −21.44 ± 12.13%; MPD: −21.50 ± 12.20%) (p < 0.05). For RPE-Set, the scores were smaller for CS2 (RPE8: 3.23 ± 0.61; RPE16: 4.32 ± 1.42; RPE24: 4.46 ± 1.51) compared to TRD (RPE8: 4.73 ± 1.33; RPE16: 5.46 ± 1.62; RPE24: 6.23 ± 1.97) (p = 0.008), as well as for Session RPE (CS2: 4.32 ± 1.59; TRD: 5.68 ± 1.75) (p = 0.015). There were no changes for jump height (CMJ: p = 0.985), and the difference between time points in CMJ (ΔCMJ: p = 0.213) and muscle soreness (DOMS: p = 0.437) were identified. Our findings suggest that using CS with a greater number of intra-set rests is more efficient even with the total rest interval equalized, presenting lower decreases in mechanical performance and lower perceptual effort responses.

Combined Accentuated Eccentric Loading and Rest Redistribution in High-Volume Back Squat: Acute Stimulus and Fatigue

“…Rather, our experimental conditions negatively affect HR and RPE, with greater values during exercise than TS. The findings do not support previous studies where RR alleviated HR (2,18,34) and RPE (1,2,10,13,(21)(22)(23)(24)28,35,39) or are not in line with the BL responses in our study. A possible explanation for the discrepancy between this study and prior studies is that 15 seconds of intraset rests might not have been long enough to reduce a rise in HR (2,18,34) and RPE (1,2,10,13,21-24,28,35) compared with longer (30-60 seconds) intraset rests.…”

“…Nevertheless, 2 AEL 1 RR conditions cause overall 1-4% lower values in both variables averaged across 2 time points compared with TS. Collectively, 2 AEL 1 RR conditions appear to result in similar residual fatigue compared with TS, which supports our hypothesis and is attributable to RR (1,13,14,33) and a smaller number of cluster repetitions (1,13). Our data also demonstrate the synergistic effect of AEL 1 RR that seems to address the practical concern, where using multiple AEL repetitions would exacerbate residual fatigue.…”

“…However, a recent systematic review and meta-analysis has suggested that RR can attenuate various fatigue indices such as blood lactate (BL) and rating of perceived exertion (RPE) (20). In addition, investigators have found that RR alleviated rises in heart rate (HR) (2,18,34) and impaired countermovement jump (CMJ) height (1,13,14,33). Importantly, RR using 1 or 2 cluster repetitions can further mitigate fatigue compared with RR using 4 or more cluster repetitions during or after high-volume BS exercise (1,13,22,23).…”

“…In addition, investigators have found that RR alleviated rises in heart rate (HR) (2,18,34) and impaired countermovement jump (CMJ) height (1,13,14,33). Importantly, RR using 1 or 2 cluster repetitions can further mitigate fatigue compared with RR using 4 or more cluster repetitions during or after high-volume BS exercise (1,13,22,23). Given that the number of AEL repetitions is determined by set structure, acute fatigue elicited by a greater number of AEL repetitions can be potentially attenuated by a smaller number of cluster repetitions.…”

“…In addition, 2 AEL 1 RR conditions were hypothesized to result in similar fatigue responses compared with TS given that AEL-induced fatigue may be buffered by RR but not to the same degree as RR only because of eccentric overloading. Finally, 2 AEL 1 RR conditions would induce similar fatigue responses given that the effect of a greater number of AEL repetitions on fatigue is potentially reduced by a smaller number of cluster repetitions (1,13,22,23).…”