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.

Keywords: Delayed Onset Muscle Soreness; back squat; intra-set rest; jump performance; rating of perceived exertion; resistance training; rest redistribution; young athletes.

Figure 1

Summary of the study. 1st day refers to the familiarization session while 2nd, 3rd, and 4th days refers to the experimental sessions. Traditional (TRD), Cluster 1 (CS1), and Cluster 2 (CS2) set configurations for the back squat exercise.

Figure 2

Study design—Traditional (TRD), Cluster 1 (CS1), and Cluster 2 (CS2). TQR: Total Quality Recovery Scale; DOMS: Delayed Onset Muscle Soreness (pre-protocol, 24 and 48 h post protocol); CMJ: jump height before (CMJPre) and after (CMJ at 0′, 5′, and 10′) protocol. RPE8, 16, 24: Rating of Perceived Exertion at the end of each set; S-RPE: Rating of Perceived Exertion for overall session.

Figure 3

Individual measures for Mean Propulsive Velocity (left) and Mean Propulsive Power (right) for Protocols CS2 (Cluster 2), CS1 (Cluster 1), and TRD (Traditional). Data are expressed as mean value for protocol.

Figure 4

Mean Propulsive Velocity for Protocols CS2 (Cluster 2), CS1 (Cluster 1), and TRD (Traditional). Data are expressed as mean values and standard error.

Figure 5

Mean Propulsive Power for Protocols CS2 (Cluster 2), CS1 (Cluster 1), and TRD (Traditional). Data are expressed as mean values and standard error.

Figure 6

Rating of Perceived Exertion scores in arbitrary units (A.U.) for participants as individual measures (white dots) and overall sample mean (black rectangles) in the sets of each protocol.