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Acute effects of a cluster-set protocol on hormonal, metabolic and performance measures in resistance-trained males
European Journal of Sport Science
Abstract
Abstract Limited research exists on rest-pause or cluster-set (CS) protocols. Acute effects of a traditional set (TS) and CS protocols of resistance exercise on serum growth hormone (GH), cortisol (C), blood lactate (BL), countermovement vertical jump (CMVJ) and standing long jump (SLJ) were compared. Eleven resistance-trained males (22.9±2.6 year; 176.9±10.6 cm; 78.5±1.6 kg; 12.9±3.1% BF) completed one repetition maximum tests for clean pull (CP), back squat (BS) and bench press (BP). Subjects were then randomly assigned to TS or CS protocols for sessions 2 and 3, and performed CP and BS lifts followed by two circuits of three sets of three exercises. GH, C, BL, CMVJ and SLJ were measured pre-exercise (Pre), mid-exercise following completion of CS or TS protocol (Mid), immediately (IP), 15 (15P) and 30 (30P) minutes post-exercise. Repeated measures ANOVAs examined differences in GH, C, BL, CMVJ and SLJ. No differences (p>0.05) existed between protocols for GH and C. GH levels 15P were elevated (p<0.05) above 30P (15.78 + 4.66 vs. 12.10 + 4.66 µg(.)L(-1)). C levels 30P were elevated (p<0.05) above Pre (716.85 + 102.56 vs. 524.79 + 75.79 nmol(.)L(-1)). Interaction (p <0.05) existed between protocol and time for BL; mid-BL was lower for CS than TS (7.69±3.73 vs. 12.78±1.90 mmol(.)L(-1)). Pooled data for CMVJ and SLJ were greater (p <0.05) across the CS protocol. The less metabolically taxing CS protocol resulted in better sustainability of jump measures.
... The first possible scenario is when AEL and AS are used together in a single exercise (AEL 1 AS) where practitioners may simultaneously increase volume load due to eccentric overload and attenuate various acute fatigue indicators (20) (Figure 1A). If this fails to manage fatigue levels, the second possible scenario plays a complementary role where AEL 1 AS is used in primary exercises while AS is used in accessory exercises so that practitioners could separately accomplish these 2 effects across multiple exercises in a training session (36,48,79,80,113) (Figure 1B). Although this review primarily discusses AEL and AS together, practitioners could increase the load while managing various acute fatigue indicators in primary exercises when using AS with additional load (AS 1 L) (17,18,63,135) (Figure 1C). ...
... The practical considerations of AS are usually associated with time depending on the type of AS (67,72,93,133). Simply, rest redistribution (RR) may be an appropriate type of AS for high-volume exercises since it does not add extra intraset rests, keeping the same training session time as TS (48,78,79,113). By contrast, given that basic cluster sets (basic CSs) and interrepetition rest (IRR) introduce extra intraset rests, they may be appropriate types of AS for low-volume exercises (63,134,135,149), which would not markedly extend training session time compared with TS. Collectively, these practical considerations of AEL and AS might alleviate limitations in the applied setting and thus make the prescription AEL, AS, or both readily available. ...
... Evidence indicates that AS and TS are equally effective in increasing BS and BP 1RM (3)(4)(5)29,32,33,65,72,112) despite some exceptions where AS caused greater (22,101,153) and lower (39,59,78,154) increases in BS and BP strength compared with TS (see Table 3, Supplemental Digital Content 1, http://links.lww.com/JSCR/A547). A possible mechanism of equal effectiveness may be the interplay of primary stimuli (26)(27)(28) such as superior mechanical responses, lower metabolic responses (67,76), and equivalent anabolic hormonal responses (48,84,103) compared with TS. To address this, Davies et al. (31) doubled the volume for RR (6 sets of 5 repetitions) using the same load (85% 1RM) but did not find greater increases in BP 1RM compared with TS (3 sets of 5 repetitions). ...
Chae, S, McDowell, KW, Baur, ML, Long, SA, Tufano, JJ, and Stone, MH. Accentuated eccentric loading and alternative set structures: A narrative review for potential synergies in resistance training. J Strength Cond Res 38(11): 1987–2000, 2024—As athletes become adapted to training over time, it becomes more difficult to develop their strength and power. In a conventional resistance training strategy, volume or load may be increased to provide novel stimuli to break through a plateau. However, physiological stress markers increase with increased volume or load, which is an innate shortcoming. In that case, practitioners strive to develop unconventional strategies that could increase training stimuli while adjusting fatigue. Two programming tactics, accentuated eccentric loading (AEL) using eccentric overload and alternative set structures (AS) using intraset rests, have been reported to increase training stimuli and alleviate fatigue, respectively. Importantly, when merging AEL and AS in various contexts, the 2 benefits could be accomplished together. Because AEL and AS cause different outcomes, it is important to deal with when and how they may be integrated into periodization. Moreover, prescribing eccentric overload and intraset rests requires logistical considerations that need to be addressed. This review discusses the scientific and practical aspects of AEL and AS to further optimize strength and power adaptations. This review discusses (a) scientific evidence as to which tactic is effective for a certain block, (b) potential practical applications, and (c) related discussions and future research directions.
... 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). 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 traditional sets (TS), a common method to increase total volume load in a high-volume exercise is to apply greater percentage of 1 repetition maximum (1RM). However, regardless of loading schemes, TS have been reported to increase various fatigue variables such as cardiovascular (HR) (2,34), perceptual (RPE) (20), and residual fatigue (impaired CMJ height) (13,14) during and after high-volume BS exercise. Although TS causes a considerable increase in metabolic stress (BL), as a stimulus (20), it serves as a fatigue index. ...
... Furthermore, 2 AEL 1 RR conditions cause greater HR, RPE, and VȮ 2 and similar RER during exercise with similar CMJ height compared with TS. Our data partially support our hypotheses and the previous literature that used AEL (37,43,44) and RR (1,2,10,13,14,18,19,(21)(22)(23)(24)28,(32)(33)(34)(35)39). ...
Chae, S, Long, SA, Lis, RP, McDowell, KW, Wagle, JP, Carroll, KM, Mizuguchi, S, and Stone, MH. Combined accentuated eccentric loading and rest redistribution in high-volume back squat: Acute stimulus and fatigue. J Strength Cond Res 38(4): 648–655, 2024—The purpose of this study was to examine acute stimulus and fatigue responses to combined accentuated eccentric loading and rest redistribution (AEL + RR). Resistance-trained men (n = 12, 25.6 ± 4.4 years, 1.77 ± 0.06 m, and 81.7 ± 11.4 kg) completed a back squat (BS) 1 repetition maximum (1RM) and weight releaser familiarization session. Three BS exercise conditions (sets × repetitions × eccentric-concentric loading) consisted of (a) 3 × (5 × 2) × 110/60% (AEL + RR 5), (b) 3 × (2 × 5) × 110/60% (AEL + RR 2), and (c) 3 × 10 × 60/60% 1RM (traditional sets [TS]). Weight releasers (50% 1RM) were attached to every first repetition of each cluster set (every first, third, fifth, seventh, and ninth repetition in AEL + RR 5 and every first and sixth repetition in AEL + RR 2). The AEL + RR 5 resulted in greater total volume load (sets × repetitions × eccentric + concentric loading) (6,630 ± 1,210 kg) when compared with AEL + RR 2 (5,944 ± 1,085 kg) and TS (5,487 ± 1,002 kg). In addition, AEL + RR 5 led to significantly (p < 0.05) greater rating of perceived exertion (RPE) after set 2 and set 3 and lower blood lactate (BL) after set 3 and 5, 15, and 25 minutes postexercise than AEL + RR 2 and TS. There was a main effect of condition for BL between AEL + RR 5 (5.11 ± 2.90 mmol·L−1), AEL + RR 2 (6.23 ± 3.22 mmol·L−1), and TS (6.15 ± 3.17 mmol·L−1). In summary, AEL + RR 5 results in unique stimulus and fatigue responses. Although it may increase perceived exertion, coaches could use AEL + RR 5 to achieve greater back squat total volume load while reducing BL accumulation.
... In a study verifying neuromuscular fatigue through electromyography, it was evidenced that individuals who performed the Cluster configuration presented a reduced increase in electromyographic amplitude along with a lower reduction in frequency [25], pointing to a lower accumulation of fatigue. There was also less accumulation of metabolic substrates verified through the reduction in lactate, ammonia, and cortisol concentrations [17,[26][27][28][29]. verified that besides the benefits of maintenance of performance in mechanical variables and less metabolic accumulation during exercise, there was also an association between more extended inter-repetition interval periods and lower perceptual responses measured through perceived effort, along with higher performance in vertical jump height. ...
... However, for CS2 and CS1 × TRD, moderate effect sizes were demonstrated between conditions (CS2-TRD: 0.81; CS1-TRD: 0.84) when comparing ∆CMJ for Pre-0 . These finds were contrary to the results from Girman et al. [26] and Varela-Olalla et al. [29]. However, different from our study, Girman et al. [26] used two exercises and two circuits in their design, which could have enhanced fatigue for the traditional configuration. ...
... These finds were contrary to the results from Girman et al. [26] and Varela-Olalla et al. [29]. However, different from our study, Girman et al. [26] used two exercises and two circuits in their design, which could have enhanced fatigue for the traditional configuration. On the other hand, the study by Varela-Olalla et al. [29] was not randomized since the design required participants to reach 20% velocity loss in the traditional configuration session, then they accounted for the same number of repetitions for the cluster configuration, in addition to the use of half squat exercises. ...
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.
... In the companion article (3), we discussed the studies that elucidated mechanical responses between rest redistribution (RR) and traditional sets (TS) and how these responses can be affected by additional loads during the RR with heavier loads (RR 1 L) protocol. Apart from the mechanical responses, multiple researchers have focused on examining metabolic (10,14,27,30,31,33,39) and perceptual (1,7,16,18,19,26,27,33,39) responses to RR. Jukic et al. (15) demonstrated that the use of RR reduces mechanical fatigue, metabolic stress, and perceived exertion in a systematic review and meta-analysis. Nonetheless, various other physiological [endocrine (10,27,30), inflammatory (24,29), and cardiovascular (1,13)] responses have been elucidated less widely. ...
... Apart from the mechanical responses, multiple researchers have focused on examining metabolic (10,14,27,30,31,33,39) and perceptual (1,7,16,18,19,26,27,33,39) responses to RR. Jukic et al. (15) demonstrated that the use of RR reduces mechanical fatigue, metabolic stress, and perceived exertion in a systematic review and meta-analysis. Nonetheless, various other physiological [endocrine (10,27,30), inflammatory (24,29), and cardiovascular (1,13)] responses have been elucidated less widely. While mechanical responses per se provide information about performance and fatigue (15,22,38), an understanding of other physiological responses can provide more insight into various fatigue indices and training considerations from a longitudinal adaptation perspective (4)(5)(6)35). ...
... To date, studies have examined endocrine responses between RR and TS using the same % back squat (BS) 1 repetition maximum (1RM) (10,27,30). Oliver et al. (30) observed greater growth hormone (GH) (a main effect of protocol) and cortisol (C) (at 30 minutes postexercise) responses for TS compared with RR, but total testosterone (TT) responses were not found to be different. ...
Chae, S, Hill, DW, Bailey, CA, Moses, SA, McMullen, SM, and Vingren, JL. Acute physiological and perceptual responses to rest redistribution with heavier loads in resistance-trained men. J Strength Cond Res 37(5): 994–1000, 2023—The purpose of this study was to explore the effect of rest redistribution with heavier loads (RR + L) on physiological and perceptual responses in resistance-trained men. Eight men who had back squat (BS) 1 repetition maximum (1RM) to body mass ratio; 1.8 ± 0.2 completed 2 BS exercise sessions in a counterbalanced and a randomized order; RR + L: 4 sets of (2 × 5) repetitions with 90-second interset rest and 30-second intraset rest using 75% BS 1RM and traditional sets (TS): 4 sets of 10 repetitions with 120-second interset rest using 70% BS 1RM. Blood samples were collected before exercise, immediately post exercise, and 5, 15, and 30 minutes post exercise for the analysis of growth hormone (GH), total testosterone (TT), cortisol (C), and blood lactate (BL), whereas rating of perceived exertion (RPE) and heart rate (HR) were measured immediately after each set of the BS exercise. While neither main effect of condition nor interaction existed, there was a significant (p < 0.05) main effect of time point (and set) for GH, TT, C, BL, RPE, and HR. Volume load was greater for RR + L compared with TS (4,074.9 ± 786.7 kg vs. 3,796.3 ± 714.8 kg). In conclusion, RR + L increases volume load by approximately 7% but does not seem to influence GH (g = −0.15), TT (g = −0.09), BL (g = −0.22), RPE (g = 0.14), and HR (g = −0.08) responses. Practitioners may consider using RR + L to increase volume load without increasing acute fatigue responses.
... 91 To account for the limited time normally available within applied environments, several authors have recommended what is referred to as a rest-redistribution set. 16,50,67 This training method can be applied by: 1) redistributing the interset rest interval to include the interrepetition or intra-set rest interval and/or 2) decreasing the total number of repetitions performed per set and increasing the total number of sets while the overall rest is unchanged ( Figure 2). 89 Several authors have suggested that the rest-redistribution set is a more effective set configuration for maintaining mechanical performance, 32,64,67 lessening metabolic stress, 16,66,72 and decreasing perceptual exertion, 5,39,50 than traditional sets, while avoiding extending the training session time. ...
... 16,50,67 This training method can be applied by: 1) redistributing the interset rest interval to include the interrepetition or intra-set rest interval and/or 2) decreasing the total number of repetitions performed per set and increasing the total number of sets while the overall rest is unchanged ( Figure 2). 89 Several authors have suggested that the rest-redistribution set is a more effective set configuration for maintaining mechanical performance, 32,64,67 lessening metabolic stress, 16,66,72 and decreasing perceptual exertion, 5,39,50 than traditional sets, while avoiding extending the training session time. Although standard cluster sets and rest-redistribution sets have often been referred to interchangeably within the coaching and scientific literature, 2,4,16,32,33,48,[64][65][66][67]92,97 this has caused some confusion as these set strategies are likely different constructs. ...
... 89 Several authors have suggested that the rest-redistribution set is a more effective set configuration for maintaining mechanical performance, 32,64,67 lessening metabolic stress, 16,66,72 and decreasing perceptual exertion, 5,39,50 than traditional sets, while avoiding extending the training session time. Although standard cluster sets and rest-redistribution sets have often been referred to interchangeably within the coaching and scientific literature, 2,4,16,32,33,48,[64][65][66][67]92,97 this has caused some confusion as these set strategies are likely different constructs. Based upon their meta-analytic study, Jukic et al 49 recently reported that standard cluster sets and rest-redistribution sets are different constructs as rest-redistribution sets are less effective for maintaining mechanical performance, mitigating metabolic stress and perceptual exertion when compared to standard cluster sets. ...
Altering the configuration of a training set can add a unique training
variation to a resistance training programme. Cluster sets can be used
by strength and conditioning (S&C) professionals to modify the internal
and external training loads that impact the training adaptations that
result from resistance training. The purpose of this review is to provide
the theoretical foundation for the use of cluster sets within resistance
training programmes and to offer practical examples of how to implement
cluster sets as part of a periodised training plan.
... One alternative to CL sets is to redistribute total rest time of TR set configurations to create shorter but more frequent rest periods (12,14,24,25). This method, known as "rest redistribution" (RR), has become increasingly popular since it enables the maintenance of TR, CL and RR set configurations 4 higher movement velocities than TR sets while not extending total training time (7,9,11,14,23). ...
... countermovement jump [CMJ] height and throwing velocity). Since previous studies have generally reported lower velocity losses during training with CL and RR in comparison to TR set configurations (4,(7)(8)(9)11,23,24,26), lower reductions in the performance of dynamic actions following RT sessions comprising CL and RR structures could also be expected. In addition, although CL and RR set configurations have been frequently associated with lower ratings of perceived exertion (RPE) immediately after completing a set (8,15,24), less information exists with respect to the differences in the session RPE (sRPE) between RT sessions that only differ in the set configuration (12). ...
... These results collectively highlight that although the neuromuscular and perceptual fatigue during training could be lower for the CL and RR set configurations, the residual fatigue accumulated during RT is not affected by different set configurations. A lower level of metabolic fatigue could be responsible for the higher movement velocities observed during training for the CL and RR set configurations compared to the TR set configuration (2,4,7). However, previous research showed that metabolic fatigue drops rapidly after the last training set regardless of the set structure (i.e., TR, CL or RR) while also being consistently lower after the training than during the training (2,7,27), and this could explain the lack of differences in residual fatigue (i.e., decrements in CMJ height and throwing velocity) between the set configurations. ...
This study aimed to compare the acute effect of traditional (TR), cluster (CL) and rest redistribution (RR) set configurations on neuromuscular and perceptual measures of fatigue. Thirty-one resistance-trained men randomly performed a Control session and 3 experimental sessions consisting of the squat (SQ) and bench press (BP) exercises performed against the 10-repetition maximum load using TR (3 sets of 6 repetitions; 3 minutes of inter-set rest), CL (3 sets of 6 repetitions; 30 seconds of intra-set rest every 2 repetitions; 3 minutes of inter-set rest), and RR (9 sets of 2 repetitions; 45 seconds of inter-set rest) set configurations. A significant effect of “set configuration” (p=0.002) was observed for barbell velocity. The average velocity of the training session was lower for TR compared to CL (% difference = 5.09% in SQ and 5.68% in BP) and RR (% difference = 5.92% in SQ and 2.71% in BP). The 3 set configurations induced comparable decrements in countermovement jump height (% difference from -6.0% to -8.1%) and throwing velocity (% difference from -0.6% to -1.2%). Ratings of perceived exertion (RPE-10) values collected after the sets were higher for TR (SQ: 6.9±0.7 a.u.; BP: 6.8±0.8 a.u.) compared to CL (SQ: 6.2±0.8 a.u.; BP: 6.4±0.7 a.u.) and RR (SQ: 6.2±0.8 a.u.; BP: 6.6±0.9 a.u.), while the session RPE did not differ between the set configurations (p=0.595). CL and RR set configurations allow for higher velocities and lower RPE values during resistance training sessions not performed to failure in comparison to a TR set configuration.
... If, in fact, these hormones are altered in response to resistance exercise, it would be expected that responses might differ with exercise protocol as related to muscular strength, power (3), or hypertrophy (19). In men, blood lactate levels experience less of an increase when performing resistance exercise with intraset rest than in response to TS (6,9,15,34). Therefore, it is not unexpected that some of the aforementioned studies reported an attenuated response in growth hormone and cortisol to intraset rest compared with TS (9,34), yet the condition differences were not present for testosterone responses (9,34). ...
... Even when controlled for total rest, the differing time under tension (i.e., mechanical stress) during TS may have attenuated these growth hormone responses (34). In another study, in which the movement tempo was controlled, growth hormone and cortisol responses were similar for rest redistribution and TS, despite the difference in lactate levels (6). Yet, when different distributions of intraset rest are used with the same volume and total rest, the metabolic and hormonal responses are similar between exercise conditions regardless of lifting tempo (44). ...
... Therefore, RPE may not change if the factors driving RPE remain unchanged (e.g., mechanical or metabolic). Similar to RPE, lactate values in this study progressively increased throughout both conditions and remained elevated until 30 minutes after exercise, a finding that is in support of previous studies (6,9,34,44). However, unlike RPE where set-by-set differences were not present between conditions, lactate was greater during TS from Rep10 (set 1) through 15 minutes after training. ...
The purpose was to examine acute effects of rest redistribution on perceptual, metabolic, and hormonal responses during back squats. Twelve resistance-trained women (training age 5±2 years; one-repetition maximum (1-RM) per body mass, 1.6±0.2) performed traditional (TS, 4 sets of 10 repetitions with 120 seconds inter-set rest) and rest-redistribution sets (RR, 4 sets of two 5 repetition clusters with 30 seconds intra-set rest and 90 seconds inter-set rest) in counterbalanced order, separated by 72-hours. Both conditions were performed at 70% 1-RM with 360 seconds of total rest. Ratings of perceived exertion (RPE) were taken after each set. Blood was sampled at baseline, after each set, and at 5, 15, 30, and 60 minutes (min), as well as 24- and 48-hours post-training. Alpha level was p≤0.05. The RPE progressively increased throughout both conditions (p=0.002) with a greater overall mean for TS (5.81±0.14) than RR (4.71±0.14; p=0.003). Lactate increased above baseline and remained elevated through 15min post in both conditions (4.00±0.76; p=0.001), with greater lactate levels for TS (6.33±0.47) than RR (4.71±0.53; p<0.001). Total testosterone was elevated after set 2 (0.125±0.02; p=0.011), but no other time point, while free testosterone remained unchanged. Growth hormone continually rose from baseline to set 3 and returned to baseline by 60min post (20.58±3.19). Cortisol and creatine kinase did not change over time. No condition*time interactions existed for any hormone (p>0.05). Use of rest-redistribution resulted in lower perceived effort and lactate responses. Yet, hormone responses during rest-redistribution were no different from traditional sets.
... • Cluster set seems to reduce fatigue acutely [26], this rest provides greater maintenance of PCr reserves and an increased metabolite clearance [27,30,32]. In addition, cause less lactate and a attenuated hormonal response [30,32]. ...
... • Cluster set seems to reduce fatigue acutely [26], this rest provides greater maintenance of PCr reserves and an increased metabolite clearance [27,30,32]. In addition, cause less lactate and a attenuated hormonal response [30,32]. Reducing the increase in velocity loss in the set as a result of fatigue. ...
... • 70-20, 70-CLU faster recovery • 70-CLU→ have a degree of fatigue lower than traditional set [30,33]. Cluster Training allows a partial replacement of phosphocreatine [34] and better physical and technical pefomance [35] ...
... Two studies assessed a WL task (i.e. clean pulls or power clean) [19,21], one study used a jump squat (power) [51], one study used the bench press throw [57] and one study combined strength and WL exercises [44]. An overall effect for exercise selection was observed (SMD = 0.664, 95% CI 0.413-0.916, ...
... Likewise, the reduction in velocity was less for all loads between 60 and 80% of 1RM for the back squat in the study by Mora-Custodio et al. [50], with a benefit also demonstrated by Tufano et al. [48] using either 75% or 80% of 1RM. This observation warrants some discussion given that the studies utilising moderate loads generally had a higher overall volume/number of performed repetitions [24,25,44,47,48,56]. Thus, it could be theorised that the increase in blood lactate concentration and reduction of adenosine triphosphate and phosphocreatine stores [64] as well as alterations in other biomarkers such as cortisol during higher-volume fatiguing TS protocols [65] may be attenuated by CS paradigms. ...
... Thus, achieving the same volume load with minimal fatigue development may be a more favourable approach. It should also be noted that biochemical correlates of fatigue were only reported in a handful of the studies [23,44,46,55] examined in this meta-analysis, suggesting that further work in this area is warranted. ...
Background
Cluster sets (CSs) are a popular resistance training (RT) strategy categorised by short rest periods implemented between single or groups of repetitions. However, evidence supporting the effectiveness of CSs on acute intra-session neuromuscular performance is still equivocal.
Objective
The objective of this investigation was to determine the efficacy of a single session of CSs to attenuate losses in force, velocity and power compared to traditional set (TS) training.
Methods
Screening consisted of a systematic search of EMBASE, Google Scholar, PubMed, Scopus and SPORTDiscus. Inclusion criteria were (1) measured one or more of mean/peak force, velocity or power; (2) implemented CSs in comparison to TSs; (3) an acute design, or part thereof; and (4) published in an English-language, peer-reviewed journal. Raw data (mean ± standard deviation) were extracted from included studies and converted into standardised mean differences (SMDs) and ± 95% confidence intervals (CIs).
Results
Twenty-five studies were used to calculate SMD ± 95% CI. Peak (SMD = 0.815, 95% CI 0.105–1.524, p = 0.024) and mean (SMD = 0.863, 95% CI 0.319–1.406, p = 0.002) velocity, peak (SMD = 0.356, 95% CI 0.057–0.655, p = 0.019) and mean (SMD = 0.692, 95% CI 0.395–0.990, p < 0.001) power, and peak force (SMD = 0.306, 95% CI − 0.028 to 0.584, p = 0.031) favoured CS. Subgroup analyses demonstrated an overall effect for CS across loads (SMD = 0.702, 95% CI 0.548–0.856, p < 0.001), included exercises (SMD = 0.664, 95% CI 0.413–0.916, p < 0.001), experience levels (SMD = 0.790, 95% CI 0.500–1.080, p < 0.001) and CS structures (SMD = 0.731, 95% CI 0.567–0.894, p < 0.001) with no difference within subgroups.
Conclusion
CSs are a useful strategy to attenuate the loss in velocity, power and peak force during RT and should be used to maintain neuromuscular performance, especially when kinetic outcomes are emphasised. However, it remains unclear if the benefits translate to improved performance across all RT exercises, between sexes and across the lifespan.
... It is important to note that the training session duration could be the same for the TR, CL and IRR set configurations (i.e., equated work-torest ratio), differing only in the distribution of the rest within the training session (Tufano et al. 2017c). The CL and IRR set configurations have proven to be effective for altering mechanical, metabolic and perceptual variables when compared to TR set configurations (Iglesias-Soler et al. 2012Girman et al. 2014;Moreno et al. 2014;Oliver et al. 2015, García-Ramos et al. 2015Tufano et al. 2016Tufano et al. , 2017bGonzález-Hernández et al. 2017). ...
... Similarly, reducing the magnitude of velocity loss during resistance training has also been recommended to enhance athletic performance (Pareja-Blanco et al. 2017). In this regard, CL and IRR set configurations may be effective at maintaining higher velocities and power outputs during resistance training sessions (Iglesias-Soler et al. 2012Girman et al. 2014;Moreno et al. 2014;Oliver et al. 2015, García-Ramos et al. 2015Tufano et al. 2016Tufano et al. , 2017bGonzález-Hernández et al. 2017). It should be noted that the vast majority of studies that have analysed the effects of CL and IRR set configurations on barbell velocity have used loads lower than the typically used during strength-oriented resistance training sessions (> 85% of the 1-repetition maximum; 1RM) (Tufano et al. 2017a). ...
... However, to the authors' knowledge no research has examined if the CL and IRR set configurations could also allow for higher movement velocities when heavy loads (≥ 85%1RM) are used during upper-body exercises (e.g., bench press). In addition, although many studies have explored the acute effect of CL and IRR set configurations in male subjects (Iglesias-Soler et al. 2012Girman et al. 2014;Moreno et al. 2014;Oliver et al. 2015Oliver et al. , 2016García-Ramos et al. 2015Tufano et al. 2016Tufano et al. , 2017bGonzález-Hernández et al. 2017), only two studies have explored their effects on women (Koefoed et al. 2018;Korak et al. 2018). Korak et al. (2018) found in trained females that the total volume lifted during the back squat exercise was higher following a IRR set configuration (4 s of rest between each repetition) compared to a traditional set configuration. ...
Purpose
This study explored the acute effects of strength-oriented resistance training sessions performed using three different set configurations on barbell velocity and the force–velocity (F–v) relationship of upper-body muscles in men and women.
Method
Thirteen men (age: 23.8 ± 2.5 years; 6-repetition maximum [6RM] load: 73.4 ± 15.6 kg) and 13 women (age: 21.5 ± 1.4 years; 6RM load: 32.8 ± 5.2 kg) performed 24 repetitions with a 6RM load during the bench press exercise using traditional (TR: 6 sets of 4 repetitions with 3 min of rest between sets), cluster (CL: 6 sets of 4 repetitions with 15 s of intra-set rest every two repetitions and 2 min and 45 s of rest between sets) and inter-repetition rest (IRR: 1 set of 24 repetitions with 39 s of rest between repetitions) set configurations. The F–v relationship parameters [maximum force (F0), maximum velocity (v0) and maximum power (Pmax)] were determined before and after each training session.
Results
The average training velocity did not differ between the three set configurations (p = 0.234), but the IRR set configuration generally provided higher velocities during the last repetition of each set. Significant decreases in F0 (p = 0.001) and Pmax (p = 0.024) but not in v0 (p = 0.669) were observed after the training sessions. Comparable velocity loss was observed for men and women (− 12.1% vs. − 11.3%; p = 0.699).
Conclusions
The administration of very short intra-set rest periods does not allow for the attainment of higher velocities than traditional set configurations during strength-oriented resistance training sessions conducted with the bench press exercise when the work-to-rest ratio is equated.
... Traditional loading (TL) schemes are believed to enhance adaptation, at least partly through acute fatigue. Acute fatigue could enhance motor unit recruitment (19), and increase muscle (and whole body) metabolism and metabolite production (5,6,8,9,17,18,28,29,32), both of which may enhance adaptation to training (32). However, fatigue and increased production of metabolites as a primary stimulus for increased strength and power have both been questioned (3,5). ...
... Although CS protocols have been previously investigated, there are few studies describing both kinetic and kinematic characteristics and there are a number of limitations in these studies. A number of intraset rest periods and exercises have been used (2,4,5,6,(10)(11)(12)(13)(14)(15)(17)(18)(19)(20)(21)(22)(25)(26)(27)(28)(29)34,35). These studies have demonstrated varying results due to the variety of protocols used. ...
... Therefore, it is possible that interset rest may allow for partial replenishment of PCr, which is a more efficient energy source and may allow for higher power outputs. It has also been reported that lactate values are higher for TL than for CS, suggesting a reliance on anaerobic glycolysis for energy (2,6,29). Gorostiaga also reported higher reliance on lactate during the last 5 repetitions in a set of 10 (8). ...
Wetmore, A, Wagle, JP, Sams, ML, Taber, CB, DeWeese, BH, Sato, K, and Stone, MH. Cluster set loading in the back squat: Kinetic and kinematic implications. J Strength Cond Res XX(X): 000-000, 2018-As athletes become well trained, they require greater stimuli and variation to force adaptation. One means of adding additional variation is the use of cluster loading. Cluster loading involves introducing interrepetition rest during a set, which in theory may allow athletes to train at higher absolute intensities for the same volume. The purpose of this study was to investigate the kinetic and kinematic implications of cluster loading as a resistance training programming tactic compared with traditional loading (TL). Eleven resistance-trained men (age = 26.75 ± 3.98 years, height = 181.36 ± 5.96 cm, body mass = 89.83 ± 10.66 kg, and relative squat strength = 1.84 ± 0.34) were recruited for this study. Each subject completed 2 testing sessions consisting of 3 sets of 5 back squats at 80% of their 1 repetition maximum with 3 minutes of interset rest. Cluster loading included 30 seconds of interrepetition rest with 3 minutes of interset rest. All testing was performed on dual-force plates sampling at 1,000 Hz, and the barbell was connected to 4 linear position transducers sampling at 1,000 Hz. Both conditions had similar values for peak force, concentric average force, and eccentric average force (p = 0.25, effect size (ES) = 0.09, p = 0.25, ES = 0.09, and p = 0.60, ES = 0.04, respectively). Cluster loading had significantly higher peak power (PP) (p < 0.001, ES = 0.77), peak and average velocities (p < 0.001, ES = 0.77, and p < 0.001, ES = 0.81, respectively), lower times to PP and velocity (p < 0.001, ES = -0.68, and p < 0.001, ES = -0.68, respectively) as well as greater maintenance of time to PP (p < 0.001, ES = 1.57). These results suggest that cluster loading may be superior to TL when maintaining power output and time point variables is the desired outcome of training.
... In fact, a recent study (Pareja-Blanco et al., 2017) has reported that a lower degree of fatigue within the set resulted in greater improvements on the neuromuscular performance than a greater degree of fatigue. For this reason, several studies (Girman, Jones, Matthews, & Wood, 2014;Hardee, Triplett, Utter, Zwetsloot, & McBride, 2012;Iglesias-Soler et al., 2012) have suggested that introducing an IRR period could be an alternative method for attenuating the fatigue-induced performance decrements associated with traditional configuration in resistance exercise. ...
... However, studies analyzing the acute effects of IRR intervals have used a single training set (Garcia-Ramos et al., 2015;Iglesias-Soler et al., 2012;Lawton et al., 2006;Moir, Graham, Davis, Guers, & Witmer, 2013) and/or a unique load magnitude González-Hernádez et al., 2017;Hansen, Cronin, & Newton, 2011;Hardee et al., 2012;Iglesias-Soler et al., 2012;Oliver et al., 2015;Rahimi et al., 2010) Therefore, it is difficult to extrapolate findings from this type of research to the responses associated with a typical RT session. Moreover, to the best of our knowledge, only four studies (Denton & Cronin, 2006;Garcia-Ramos et al., 2017;Girman et al., 2014;González-Hernádez et al., 2017) have compared the acute metabolic response induced by IRR intervals with traditional set configurations. These studies (Denton & Cronin, 2006;Garcia-Ramos et al., 2017;Girman et al., 2014;González-Hernádez et al., 2017) concluded that cluster set configurations induced lower blood lactate concentrations than traditional sets, although results relating to protocols using the full squat exercise are scarce (González-Hernádez et al., 2017). ...
... Moreover, to the best of our knowledge, only four studies (Denton & Cronin, 2006;Garcia-Ramos et al., 2017;Girman et al., 2014;González-Hernádez et al., 2017) have compared the acute metabolic response induced by IRR intervals with traditional set configurations. These studies (Denton & Cronin, 2006;Garcia-Ramos et al., 2017;Girman et al., 2014;González-Hernádez et al., 2017) concluded that cluster set configurations induced lower blood lactate concentrations than traditional sets, although results relating to protocols using the full squat exercise are scarce (González-Hernádez et al., 2017). ...
This study aimed to analyze the acute effect of inter-repetition rest (IRR) intervals on mechanical and metabolic response during four resistance exercise protocols (REPs). Thirty resistance-trained men were randomly assigned to: continuous repetitions (CR), 10 s (IRR10) or 20 s (IRR20) inter-repetition rest. The REPs consisted of 3 sets of 6, 5, 4 and 3 repetitions against 60, 70, 75 and 80% 1RM, respectively, in the full squat exercise. Muscle fatigue was assessed using: percentage of velocity loss over three sets, percentage of velocity loss against the ~1 m·s⁻¹ load (V1 m·s⁻¹), and loss of countermovement jump (CMJ) height pre-post exercise. Blood lactate was measured before and after exercise. The percentage of velocity loss over three sets and lactate concentration were significantly lower (P < 0.05) for IRR groups compared to CR in all REPs. The CR group showed a significantly higher (P < 0.05) velocity loss against V1 m·s⁻¹ load and loss of CMJ height pre-post exercise than IRR groups in REP against 60% 1RM. In conclusion, both IRR groups produced a significant lower degree of fatigue compared to CR group. However, no significant differences were found in any measured variables between IRR configurations.
... One potential strategy for offsetting the fatigue-induced performance decrements associated with TS could be the use of CS (33). Based on the work of Gorostiaga et al. (29)(30)(31), using CS structures to provide more frequent rest periods should result in enhanced recovery via a greater maintenance of PCr stores and increased metabolite clearance compared with TS training (19,27,75). By using CS structures, there may be an increase in substrate availability (i.e., PCr and ATP) that could result in the maintenance of movement velocity throughout an entire set and, ultimately, an entire training session. ...
... Set structures inclusive of normal interset rest periods accompanied by preplanned rest intervals within a set are referred to as CS structures (11,33,(37)(38)(39)91). Conceptually, the addition of short rest periods within a set while maintaining normal rest periods between sets may offer a methodology for maximizing individual repetition performance while reducing accumulated fatigue seen during TS (27,(32)(33)(34)(35)39,91). However, because of the wide range of protocols using the CS terminology (further discussed in the "Set Structure Terminology" section of this article), CS have simply become a set structure in which rest periods are more frequent than TS. ...
... One type of CS subclass is created when the redistribution of interset rest intervals occurs (5,19,27,36,50,58,69,(74)(75)(76)102). ...
When performing a set of successive repetitions, fatigue ensues and the quality of performance during subsequent repetitions contained in the set decreases. Oftentimes, this response may be beneficial, as fatigue may stimulate the neuromuscular system to adapt, resulting in a super-compensatory response. However, there are instances in which accumulated fatigue may be detrimental to training or performance adaptations (i.e. power development). In these instances, the ability to recover and maintain repetition performance would be considered essential. By providing intermittent rest between individual repetitions or groups of repetitions within a set, an athlete is able to acutely alleviate fatigue, allowing performance to remain relatively constant throughout an exercise session. Within the scientific literature, a set that includes intermittent rest between individual repetitions or groups of repetitions within a set is defined as a cluster set. Recently, cluster sets have received more attention as researchers have begun to examine the acute and chronic responses to this relatively novel set structure. However, much of the rest-period terminology within the literature lacks uniformity and many authors attempt to compare largely different protocols with the same terminology. Additionally, the present body of scientific literature has mainly focused on the effects of cluster sets on power output, leaving the effects of cluster sets on strength and hypertrophy relatively unexplored. Therefore, the purpose of this review is to further delineate cluster set terminology, describe the acute and chronic responses of cluster sets, and explain the need for further investigation of the effects of cluster sets.
... CLU incorporate a short rest (typically 15-30 s) between individual repetitions (inter-repetition rest) or group of repetitions (intra-set rest) (Haff et al. 2008). The ability to maintain greater mechanical power output is facilitated by the ability of the phosphagen and glycolytic energy systems to recover during the added rest periods as evidenced by studies demonstrating lower blood lactate concentrations (Girman et al. 2014;Goto et al. 2005) following CLU when compared to TRD configurations, as well as greater intramuscular adenosine triphosphate (ATP) and phosphocreatine (PCr) concentrations (Gorostiago 2012). ...
... Goto et al. (2005) reported no elevation in growth hormone post-CLU; however, it is again likely the failure of that exercise program to induce significant elevations in blood lactate was responsible for the lack of response, as there appeared to be a similar pattern in the CLU condition although not statistically significant. On the contrary, Girman et al. (Girman et al. 2014) found no difference in growth hormone between CLU and TRD conditions in a group of trained males. In an effort to mimic a typical hypertrophy off-season training day, subjects in that study performed two exercises (clean pull and back squat) using TRD and CLU followed by two circuits in which the set and rep configurations did not differ between conditions. ...
... While significantly lower lactate values were observed immediately following CLU performance, higher lactate values than those reported herein were reported immediately following performance of a final circuit (14.6 ± 0.4 mmol l −1 , TRD; 14.3 ± 0.4 mmol l −1 , CLU), and these did not differ between conditions. Thus, the similar lactate values could have contributed to the similar growth hormone response; however, differences in TUT may, too, have influenced the results by Girman et al. (2014). Growth hormone has been shown to be elevated to a greater degree following slow movement exercise compared to normal movement (Goto et al. 2009). ...
In traditional sets (TRD) repetitions are performed continuously, whereas cluster sets (CLU) allow a brief rest between groups of repetitions. We investigated the acute mechanical, metabolic, and hormonal response to CLU in men.
Twelve resistance-trained (RT) and 11 untrained (UT) men performed TRD (4 × 10 repetitions with 2 min rest) and CLU [4 × (2 × 5) with 1.5 min rest between sets 30 s rest between clusters] at 70 % 1RM back squat in random order. Seven days separated trials. Average power and time under tension (TUT) were calculated. Blood was sampled pre, sets 1, 2, and 3; immediate post-exercise, 5, 15, 30, 60 min post-exercise for blood lactate, total testosterone (TT), free testosterone (FT), growth hormone (GH), and cortisol.
CLU produced greater average power at an increasing number of repetitions over each set with greater total volume load. TUT was shorter for RT and lower for CLU in repetitions 1, 6, 7, 8. Blood lactate was higher Set 2 through 30 min in TRD. RT had higher TT; however, the time course was similar between RT and UT. TT and FT increased immediate post-exercise and remained elevated 30 min in both conditions. GH was significantly greater during TRD with a similar pattern observed in both conditions. Cortisol was significantly lower at 30 min in CLU.
CLU allowed greater total volume load, shorter TUT, greater average power, similar anabolic hormonal response, and less metabolic stress. The acute response was similar despite training status.
... The implementation of this methodology is an effective strategy to alleviate the mechanical fatigue induced during training sessions (23,26,38). In addition, cluster training is also effective in ameliorating acute post-RT mechanical fatigue (7,23,30,39), although this positive effect was smaller than that observed within the session (20). Importantly, to the best of our knowledge, no study has analyzed the effects of cluster training on the time course of recovery. ...
... In addition, 70-CLU achieved faster recovery than the REPs performing a similar number of repetitions but with higher VL (70-30 and 70-40). This may be because cluster sets provoke lower levels of fatigue and lower metabolic stress than continuous repetitions sets (4,7,23,30,39). Moreover, the short rest periods between repetitions may allow for the partial replacement of muscle PCr and ATP stores (10,12), which may attenuate increases in inosine monophosphate (32), avoiding the loss of purines from muscle tissue (15). ...
Cornejo-Daza, PJ, Villalba-Fernández, A, González-Badillo, JJ, and Pareja-Blanco, F. Time course of recovery from different velocity loss thresholds and set configurations during full-squat training. J Strength Cond Res XX(X): 000–000, 2023—The aims of the research were to examine the effects of (a) velocity loss (VL) thresholds and (b) set configuration, traditional or cluster, on time-course recovery. A randomized cross-over research design was conducted, in which 15 resistance-trained men performed 4 protocols consisting of 3 sets of 70% 1RM in full squat (SQ), differing in the VL incurred during the set assessed with a linear velocity transducer: (a) 20% (70-20), (b) 30% (70-30), (c) 40% (70-40), and in the set configuration (d) 20% of VL using a cluster methodology (70-CLU). Movement velocity against the load that elicited a 1 m·s ⁻¹ velocity at baseline measurements (V1-load) in SQ, countermovement jump (CMJ) height, and sprint time in 20 m (T20) were assessed at baseline (Pre) and postintervention (Post, 6 hour-Post, 24 hour-Post, and 48 hour-Post). The 70-20 protocol resulted in fewer total repetitions than the other protocols ( p = 0.001), whereas 70-CLU, 70-30, and 70-40 completed similar total repetitions. The 70-30 protocol significantly worsened T20 at 6 hours-Post, CMJ at 48 hours-Post, and V1-load at 6 hours-Post ( p < 0.05). The 70-40 protocol significantly impaired T20 at 6 hours-Post, and CMJ and V1-load at 24 hours-Post ( p < 0.05). No significant performance reductions were observed for 70-20 and 70-CLU at 6 hours-Post, 24 hours-Post, and 48 hours-Post. Protocols with higher VL resulted in more pronounced fatigue and a slower rate of recovery. Cluster sets (70-CLU) resulted in higher volume than protocols with a similar level of fatigue (70-20) and a quicker recovery than protocols with a similar volume (70-30 and 70-40).
... One study [72] was at unclear risk of attrition bias, not reporting how the outcome of interest was collected when participants could not complete the protocols. Two studies were at a high risk of effort bias since the participants were not encouraged to perform the concentric phase of the lift with the maximal intent or they used a metronome instead [72,75], whereas this information was unclear in one study [76]. Three studies were of a high risk of equipment bias since they used non-officially validated equipment to measure jump height or movement velocity [19,63,75]. ...
... Two studies were at a high risk of effort bias since the participants were not encouraged to perform the concentric phase of the lift with the maximal intent or they used a metronome instead [72,75], whereas this information was unclear in one study [76]. Three studies were of a high risk of equipment bias since they used non-officially validated equipment to measure jump height or movement velocity [19,63,75]. In addition, one study [72] used a rating of perceived exertion scale not validated for resistance training purposes and therefore, was also classified to be at a high risk of equipment bias. ...
Background: The alteration of individual sets during resistance training (RT) is often used to allow for greater velocity and power outputs, reduce metabolite accumulation such as lactate and also reduce perceived exertion which can ultimately affect the resultant training adaptations. However, there are inconsistencies in the current body of evidence regarding the magnitude of the effects of alternative set structures (i.e., cluster sets and rest redistribution) on these acute mechanical, metabolic, and perceptual responses during and after RT.
Objective: This study aimed to systematically review and meta-analyse current evidence on the differences between traditional and alternative (cluster and rest redistribution) set structures on acute mechanical, metabolic, and perceptual responses during and after RT, and to discuss potential reasons for the disparities noted in the literature. Methods The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed, and five databases were searched until June 2019. Studies were included when they were written in English and compared at least one acute mechanical, metabolic, or perceptual response between traditional, cluster or traditional and rest redistribution set structures in healthy adults. Random-effects meta-analyses and meta-regressions were performed where possible.
Results: Thirty-two studies were included. Pooled results revealed that alternative set structures allowed for greater absolute mean [standardized mean difference (SMD) = 0.60] and peak velocity (SMD = 0.41), and mean (SMD = 0.33) and peak power (SMD = 0.38) during RT. In addition, alternative set structures were also highly effective at mitigating a decline in velocity and power variables during (SMD = 0.83-1.97) and after RT (SMD = 0.58) as well as reducing lactate accumulation (SMD = 1.61) and perceived exertion (SMD = 0.81). These effects of alternative set structures on velocity and power decline and maintenance during RT were considerably larger than for absolute velocity and power variables. Subgroup analyses controlling for each alternative set structure independently showed that cluster sets were generally more effective than rest redistribution in alleviating mechanical, metabolic, and perceptual markers of fatigue.
Conclusion: Alternative set structures can reduce mechanical fatigue, perceptual exertion, and metabolic stress during and after RT. However, fundamental differences in the amount of total rest time results in cluster sets generally being more effective than rest redistribution in alleviating fatigue-induced changes during RT, which highlights the importance of classifying them independently in research and in practice. Additionally, absolute values (i.e., mean session velocity or power), as well as decline and maintenance of the mechanical outcomes during RT, and residual mechanical fatigue after RT, are all affected differently by alternative set structures, suggesting that these variables may provide distinct information that can inform future training decisions. Protocol Registration The original protocol was prospectively registered (CRD42019138954) with the PROSPERO (Inter-national Prospective Register of Systematic Reviews).
... Briefly, CL training consists of the introduction of short rest periods between individual repetitions or groups of repetitions performed within a training set (33). These set configurations are effective methods for maintaining the mechanical strain, while lowering metabolic and perceptual responses when compared to traditional (TR) (i.e., continuous repetitions) set configurations (3,5,8,10,12,20,21). ...
... However, CL sets have also been associated with a lower metabolic stress (5,16,21), (3,11). In this regard, an alternative to not excessively reduce the metabolic contribution of CL set configurations could be the use of shorter inter-repetition rest periods (< 20 seconds) than the commonly applied (20-40 seconds) (33). ...
This study aimed to compare mechanical and metabolic responses between traditional (TR) and cluster (CL) set configurations in the bench press exercise. In a counterbalanced randomized order, 10 men were tested with the following protocols (sets × repetitions [inter-repetition rest]): TR1: 3×10 [0-s], TR2: 6×5 [0-s], CL5: 3×10 [5-s], CL10: 3×10 [10-s], and CL15: 3×10 [15-s]. The number of repetitions (30), inter-set rest (5 min), and resistance applied (10RM) were the same for all set configurations. Movement velocity and blood lactate concentration were used to assess the mechanical and metabolic responses, respectively. The comparison of the first and last set of the training session revealed a significant decrease in movement velocity for TR1 (Effect size [ES]: -0.92), CL10 (ES: -0.85) and CL15 (ES: -1.08) (but not for TR2 [ES: -0.38] and CL5 [ES: -0.37]); while blood lactate concentration was significantly increased for TR1 (ES: 1.11), TR2 (ES: 0.90) and CL5 (ES: 1.12) (but not for CL10 [ES: 0.03] and CL15 [ES: -0.43]). Based on velocity loss, set configurations were ranked as follows: TR1 (-39.3±7.3%) > CL5 (-20.2±14.7%) > CL10 (-12.9±4.9%), TR2 (-10.3±5.3%) and CL15 (-10.0±2.3%). The set configurations were ranked as follows based on the lactate concentration: TR1 (7.9±1.1 mmol·l-1) > CL5 (5.8±0.9 mmol·l-1) > TR2 (4.2±0.7 mmol·l-1) > CL10 (3.5±0.4 mmol·l-1) and CL15 (3.4±0.7 mmol·l-1). These results support the use of TR2, CL10 and CL15 for the maintenance of high mechanical outputs, while CL10 and CL15 produce less metabolic stress than TR2.
... Cluster training (CS) introduces brief rest periods, typically 10-45 s, either between repetitions or blocks of repetitions (6,7). This approach is effective at maintaining performance during RT sessions (8)(9)(10)(11). Notably, CS displays reduced muscle damage, blood lactate concentrations, and hormonal responses compared to TS with workload-matched protocols (11,12). The inclusion of rest intervals within sets during CS is believed to contribute to the recovery of bioenergetic components like phosphocreatine (PCr) and adenosine triphosphate (ATP) (13). ...
Objective: The aim of this study was to examine the acute effects on
mechanical, neuromuscular, metabolic, and muscle contractile responses to
different set configurations in full-squat (SQ).
Methods: Twenty-two men performed three SQ sessions that consisted of 3 sets
of 12 repetitions with 60% 1RM with 4 minutes inter-set rests: a) traditional set
(TS): no rest within the set; b) cluster-6 (CS6): a 30 seconds intraset rest after
the 6th repetition of each set; and c) cluster-2 (CS2): a 30 seconds intraset
rest every 2 repetitions. Mechanical (i.e., force, velocity, and power) and
electromyography (EMG) values were recorded for every repetition. A battery
of tests was performed: a) tensiomyography (TMG), b) blood lactate c),
countermovement jump (CMJ), d) maximal isometric SQ, and e) performance
with the load that resulted in a velocity of 1 m·s−1 at baseline (V1-load).
Repeated measured ANOVA analyses were used to compare the 3 protocols.
Results: As the number of intraset rests increased (TS < CS6 < CS2), mechanical
performance was better maintained (p < 0.01) and EMG variables were less
altered (p = 0.05). At post, CS2 and CS6 displayed lower lactate concentration,
lesser reductions in CMJ height, and smaller alterations in TMG-derived
variables than TS (p < 0.05).
Conclusion: The introduction of short and frequent intraset rest periods during
resistance exercise alleviates training-induced fatigue, resulting in better
maintenance of performance. This approach can be applied during the inseason
period when minimizing fatigue is a priority
... e. 10-45 s) after a repetition or a block of repetitions, allows for greater maintenance of performance during RT sessions [3]. Although research on residual fatigue induced by cluster training is scarce [3], cluster training was shown to be effective at acutely alleviating post-RT mechanical fatigue and reducing hormonal and metabolic stress [4][5][6][7][8][9][10] and perception of effort [11][12][13][14][15][16][17][18][19][20] compared with traditional set (TS) configurations (i. e. no rest within the set). ...
The aim of this study was to examine the acute metabolic response, neuromuscular activity, and mechanical performance of different set configurations in bench-press (BP). Twenty-two resistance-trained men performed three resistance exercise protocols consisting of 3 x 12 BP repetitions at 60 % 1RM, with 4 minutes of rest between sets, but with different set configurations: (a) traditional set (TS), without rest within the set; (b) cluster-6 (CS6), with 30-second intraset rest after the sixth
repetition in each set; and (c) cluster-2 (CS2), with 30-second intraset rest every two repetitions. Mean propulsive force (MPF), velocity (MPV), power (MPP), and electromyography (EMG) values were recorded for each repetition. Blood lactate, maximal voluntary isometric BP contraction, and dynamic strength in BP were assessed pre- and post-exercise. The CS2 protocol resulted in greater mechanical performance (i. e. MPF, MPV, and MPP) and lower alterations of EMG parameters (i. e. root mean square and median frequency) during the exercise compared to CS6 and TS (TS < CS6 < CS2). The CS2 protocol induced smaller increases in lactate compared to TS and CS6. No significant “protocol x time” interactions were observed for the MVIC (maximal voluntary isometric BP contraction) variables. Introducing short but frequent intraset rest periods alleviates training-induced fatigue assessed by better performance maintenance.
... It has been suggested that higher metabolic stress promotes more anabolic hormones, which is favorable to muscle anabolism (Schoenfeld, 2013). However, existing studies all point to BCS and RR eliciting lower blood lactate but a similar endocrine response to TS when training volume and total rest time are matched (Girman et al., 2014;Oliver et al., 2015;Merrigan et al., 2020). Moreover, whether the additional metabolic stress generated by muscle failure in each set leads to greater muscle gain is still being determined. ...
Purpose: This study aimed to compare the effects on muscle hypertrophy and muscular performance of two resistance training (RT) programs that differed only in set structure: traditional set structure (TS) vs. rest redistribution set structure (RR).
Methods: Thirty untrained young men were pair-matched and randomly assigned to a TS (n = 15) or an RR (n = 15) protocol based on individual baseline measures. Participants trained for 8 weeks using the same total body RT routines performed twice weekly. The TS protocol comprised four sets of 10 repetitions per exercise with 120-s interset rest, and the RR involved eight sets of five repetitions per exercise with 51-s interset rest. Participants were tested pre- and post-intervention for body composition, regional muscle thickness, upper- and lower-body muscle maximal strength [1-repetition maximum (1RM)], mean power output and velocity at 75% 1RM and muscular endurance (repetitions to failure at 70% 1RM).
Results: Compared to baseline, both groups exhibited equally significantly decreased body fat mass (p < 0.05), increased fat-free mass (p < 0.001), muscle thickness (p < 0.05), upper and lower-body muscular maximal strength (p < 0.001) and endurance performance (p < 0.001). However, both groups only increase the lower-body power output (p < 0.001) but not the upper-body (p > 0.05). No significant differences existed between groups for all measurements (p > 0.05).
Conclusion: These results suggest that RR and TS groups have similar effects for improving muscle hypertrophy and performance in untrained young men.
... In addition, by extending the time spent at high loads, RP can help to increase the workload [1,2]. Girman et al. [21] found no difference in GH between cluster and TRT in a group of trained men. Slow movement increases GH more than tempo movement, and tempo also plays an important role [22]. ...
A rest–pause (RP) technique involves performing one or more repetitions at high resistance to failure, followed by a short rest before performing one or more repetitions. These techniques can affect neuromuscular conditions and fatigue by changing the rest time between repetitions. This study compared the effect of 12 weeks of RP and traditional resistance training (TRT) on myokines (myostatin (MSTN), follistatin (FLST) and insulin-like growth factor-1 (IGF-1)) and functional adaptations. The study recruited 29 men between the ages of 20 and 30 who had performed resistance training for at least 6 to 12 months. Participants were randomly divided into three groups: RP, TRT, and control; resistance training was performed 3 days per week for 12 weeks. The training methods of the two groups were largely similar. The results showed that RP increased IGF-1 and FLST/MSTN more than the TRT group (% change = 19.04, % change = 37.71), and only the RP and TRT groups had significant changes in the FLST/MSTN ratio compared to the control group (p < 0.001 and p = 0.02, respectively). In addition, FLST levels increased and MSTN decreased in the RP and TRT groups, but the rate of change in FLST was significant in the RP and TRT groups compared to the control group (p = 0.002 and p = 0.001, respectively). Leg press and bench press strength, and arm and thigh muscular cross-sectional area (MCSA) increased more in the RP group than in the others, and the percentage of body fat (PBF) decreased significantly. The change between strength and MCSA was significant (p ≤ 0.05), and the PBF change in RP and TRT compared to the control (ES RP group = 0.43; ES TRT group = 0.55; control group ES = 0.09) was significant (p = 0.005, p = 0.01; respectively). Based on the results, the RP training technique significantly affects strength and muscle hypertrophy more than the TRT method, which can be included in the training system to increase strength and hypertrophy.
... Cluster-sets, se traduce del inglés, como series en racimo o en grupo. saltos) (Girman, J.C., et al., 2014). Lo cual, no es un dato menor para el entrenamiento de deportes donde RFD es determinante. ...
En este libro,bajo un enfoque critico revisionista, se abordan temas relacinados con la planificacion y los componentes de la magnitud de la carga del entrenamiento para el fitness y el deporte de rendimiento.
Se proponen guias generales para el entrenamiento de la fuerza; la velocidad, rapidez y agilidad; la resistencia; la movilidad; y la estabilidad.
... However, when it comes to athletes with advanced training levels, different applications and different stimuli may be required to go beyond the force plateau. Periodization is recommended considering the nature of the sports branch in question [3,4]. ...
This study aims to comparatively analyse the effects of cluster set (CS) and traditional set (TS) applications on strength and power outputs in accentuated eccentric load (AEL) training. Thirty-two amateur male football players with at least 2 years of strength training history participated in the study (X̄̄age: 18,78 ± 0,83 years, X̄height:166,73± 8,61 cm., X̄body weight: 69,59± 6,03 kg.). Participants were randomly divided into two groups: CS (n=16) and TS (n=16). In both groups, the same “AEL Training” was applied and different set models were used. Augmented eccentric load (AEL) training was performed with 3 sets of 8 repetitions, 50% concentric and 80% eccentric of 1 Repetition Maximum (1-RM) and with a fast lifting tempo. The sets were completed with 20 seconds of rest after every two repetitions in the AEL-CS group and without any rest between repetitions in the AEL-TS group, and the training sessions were performed twice a week for 4 weeks. Countermovement jump (CMJ), 50cm drop jump-reactive strenght index (DJ-RSI) test, 1-RM strenght test, 10-20-30m sprint test and Illinois Agility Test (IAT) were performed on the athletes before and after the training. When analysing the data obtained in this study, Skewness and Kurtosis values and Kolmogorov-Smirnov values were examined to determine homogeneity. In order to compare the pre-test and post-test averages between groups, ANOVA was used for Repeated Measures, and Sample T Test was used to compare the pre-test and post-test averages within groups. The statistical significance level was determined as p<0.05. When the groups were compared, the difference in the improvement rate averages was tested. At the end of the four-week study, drop jump-reactive strength index (DJ-RSI), countermovement jump (CMJ), Illinois Agility Test (IAT) 10-20-30m sprint values and 1-RM values were improved percentage-wise in both AEL-CS and AEL-TS groups. Between the groups, a significant difference was observed between DJ-RSI, CMJ, and 10-20-m Sprint Test results (p<0.05). When we compare the results within groups, it can be concluded that the AEL-CS group showed more improvement in terms of strength, change of direction (COD) skills and Sprint compared to the AEL-TS group. In conclusion, it can be advised to use cluster set in accentuated eccentric load training in order to improve strength, Sprint and COD skills.
... This has been verified in the literature studies that adopted ISI between 2.85 s 14 and 130 s 13 . However, intermediate ISI values (10 s to 40 s) seem to be more frequently used [16][17][18][19] . Most studies did not adopt clear criteria for choosing the magnitude of the ISI and only Ho et al. (2021) 18 investigated the effects of two or more protocols with different ISI. ...
Objective: To compare the acute effect of two training protocols until concentric failure (CF) with different intra-set interval (ISI) configurations (20 s and 40 s) on total weight, the total number of repetitions, and time under tension in trained subjects. Methods: Ten men participated in the study (age = 25.1 ± 4.4 years; body mass = 76.5 ± 10.4 kg; height = 175.8 ± 9.3 cm). Two protocols were performed with 4 sets of bench press exercises and differentiated by the ISI: i) Protocol ISI-40 (40 s) - each set consisted of 6 repetitions followed by an ISI of 40 s and completed with repetitions up to CF; ii) Protocol ISI-20 (20 s) - each set consisted of 6 repetitions with ISI of 20 s every 3 repetitions followed by repetitions to CF. The intensity was 10 repetitions maximum, and the rest interval between sets of 80 s. A minimum interval of 48 h was adopted between protocols. Results: There was no significant difference in the number of repetitions (p = 0.074), in the time under tension (p = 0.353) and in the total volume (p = 0.083) between the protocols. Conclusion: The results indicate that the different ISI configurations did not distinctly influence the number of repetitions, time under tension, and total volume.
... CS is a set structure in which a short rest interval (15-45 seconds) is applied between repetitions to provide partial recovery and maximize movement speed and strength [10,11,12]. Recently, several studies have shown that instead of rest between sets, rest intervals between repetitions (cluster sets) result in lower speed and strength loss throughout the entire training session, improve mechanical performance [13], and allow larger training volume [11,13,14,15] and can reduce accumulated fatigue seen during the traditional set while maximizing repetition performance [10,11,12,16,17]. ...
Background and Study Aim: This study aims to examine the effects of the Triphasic Training Model (TTM) applied with different set designs (15-30 sec intra-set) on reactive strength index (RSI) and vertical jump values.
Material and Methods:. Sixteen male athletes over 18 with at least three years of strength training experience (2 days a week) actively engaged in sports participated in the study. The study group was divided into two groups by calculating the relative strengths. The 15-second cluster set (C15) group exercises were performed with 15 seconds of rest between repetitions, and the 30-second cluster-set (C30) group practiced the exercises with 30 seconds of rest between repetitions. The triphasic training model was applied to all study groups for six weeks. Countermovement jump (CMJ) and drop jump tests were performed on the athletes before and after the training. Optojump brand photocell system was used for CMJ and RSI tests. For the RSI test, the desk height was determined as 40cm. Kolmogorov-Smirnov values were examined to assess the homogeneity of the data. To compare the means between groups, ANOVA was used for Repeated Measures, and a t-test was used to compare the pretest-posttest mean of the groups. The statistical significance level was determined as p
... Therefore, to induce muscle hypertrophy with lighter loads (55%-70% 1RM), it may be necessary to attain higher VL thresholds than with higher intensities (70%-85% 1RM). Fatiguing bouts of resistance exercise are associated with increased metabolite accumulation, 14 endogenous hormone secretion, 15,16 and higher mechanical tension, 17 which may contribute to muscle hypertrophy. 18,19 Likewise, it has recently been shown that high VL thresholds using the squat exercise resulted in an increased basal Ca 2+ /calmodulin II-dependent protein kinase δ D phosphorylation (Thr 286 -CaMKII δ D ), which was associated with muscle hypertrophy and the number of repetitions completed during the training intervention. ...
Purpose:
To compare the effect of 4 velocity-loss (VL) thresholds-0% (VL0), 15% (VL15), 25% (VL25), and 50% (VL50)-on strength gains, neuromuscular adaptations, and muscle hypertrophy during the bench press (BP) exercise using intensities ranging from 55% to 70% of 1-repetition maximum (1RM).
Methods:
Fifty resistance-trained men were randomly assigned to 4 groups that followed an 8-week (16 sessions) BP training program at 55% to 70% 1RM but differed in the VL allowed in each set (VL0, VL15, VL25, and VL50). Assessments performed before (pre) and after (post) the training program included (1) cross-sectional area of pectoralis major muscle, (2) maximal isometric test, (3) progressive loading test, and (4) fatigue test in the BP exercise.
Results:
A significant group × time interaction was found for 1RM (P = .01), where all groups except VL0 showed significant gains in 1RM strength (P < .001). The VL25 group attained the greatest gains in 1RM strength and most load-velocity relationship parameters analyzed. A significant group × time interaction was observed for EMG root mean square in pectoralis major (P = .03) where only the VL25 group showed significant increases (P = .02). VL50 showed decreased EMG root mean square in triceps brachii (P = .006). Only the VL50 group showed significant increases in cross-sectional area (P < .001).
Conclusions:
These findings indicate that a VL threshold of about 25% with intensities from 55% to 70% 1RM in BP provides an optimal training stimulus to maximize dynamic strength performance and neuromuscular adaptations, while higher VL thresholds promote higher muscle hypertrophy.
... Therefore, to induce muscle hypertrophy with lighter loads (55%-70% 1RM), it may be necessary to attain higher VL thresholds than with higher intensities (70%-85% 1RM). Fatiguing bouts of resistance exercise are associated with increased metabolite accumulation, 14 endogenous hormone secretion, 15,16 and higher mechanical tension, 17 which may contribute to muscle hypertrophy. 18,19 Likewise, it has recently been shown that high VL thresholds using the squat exercise resulted in an increased basal Ca 2+ /calmodulin II-dependent protein kinase δ D phosphorylation (Thr 286 -CaMKII δ D ), which was associated with muscle hypertrophy and the number of repetitions completed during the training intervention. ...
Purpose: To compare the effect of 4 velocity loss (VL) thresholds—0%, 15%, 25% (VL25), and 50% (VL50)—on strength gains, neuromuscular adaptations, and muscle hypertrophy during the bench press (BP) exercise using intensities ranging from 55% to 70%, 1-repetition maximum (1RM). Methods: Fifty resistance-trained men were randomly assigned to 4 groups that followed an 8-week (16 sessions) BP training program at 55% to 70% 1RM but differed in the VL allowed in each set (VL 0%, VL 15%, VL25, and VL50). Assessments performed before (pre) and after (post) the training program included: (1) crosssectional area of pectoralis major muscle; (2) maximal isometric test; (3) progressive loading test; and (4) fatigue test, in the BP exercise. Results: A significant group × time interaction was found for 1RM (P = .01), where all groups except VL 0% showed significant gains in 1RM strength (P < .001). The VL25 group attained the greatest gains in 1RM strength and most load–velocity relationship parameters analyzed. A significant group × time interaction was observed for EMG root mean square in pectoralis
major (P = .03) where only the VL25 group showed significant increases (P = .02). VL50 showed decreased EMG root mean square in triceps brachii (P = .006). Only the VL50 group showed significant increases in cross-sectional area (P < .001). Conclusions: These findings indicate that a VL threshold of about 25% with intensities from 55% to 70% 1RM in BP provides an optimal training stimulus to maximize dynamic strength performance and neuromuscular adaptations, while higher VL thresholds promote higher muscle hypertrophy.
... In relation to La accumulation, TT showed higher values in this parameter after training with respect to cluster configurations. This is in agreement with previous studies that examined the effect of different set configurations on metabolic responses [17,19,23,39]. ...
This study compared the perceptual responses, physiological indicators and technical parameters between different training protocols focused on upper body exercises. A randomized crossover design was performed, and 12 trained individuals (age: 27.1 ± 5.7 years; height: 173.7 ± 10.7 cm; BMI: 23.9 ± 2.3) completed three resistance training sessions under different protocols separated by at least 72 h: traditional training (TT) (4 x 6 repetitions at 85% of 1RM with 120 s of rest between sets), cluster 1 (CL1) (4 x 2+2+2 repetitions at 85% of 1RM with 15 s of intra-rep rest and 80 s between sets), and cluster 2 (CL2) (24 repetitions at 85% of 1RM with 15 s of inter-set recovery). Before training, arterial blood pressure (BP) and repetitions to failure of pull-up and push-up (FT) were collected. Muscle oxygen saturation (SmO2) in the chest and movement velocity were evaluated in barbell bench press during the training session. After finishing, lactate, BP, rate of perceived
exertion and FT were assessed. The percentage of velocity loss (TT: 19.24%; CL1: 5.02% and CL2: 7.30%) in the bench press and lactate concentration (TT: 8.90 mmol·l-1; CL1: 6.13 mmol·l-1 and CL2: 5.48 mmol·l-1) were significantly higher (p < 0.05) for TT compared to both CLs. RPE values were higher (p < 0.05) in TT compared to CL1 (7.95 a.u. vs. 6.91 a.u., respectively). No differences (p > 0.05) were found between protocols for SmO2, BP, FT, pain or heart rate between set configurations. Cluster configurations allow one to maintain higher
movement velocity and lower lactate and RPE values compared to a traditional configuration, but with similar concentrations of SmO2.
... When using the same resistance exercise load, rest redistribution (RR) that incorporates intra-set rest results in no difference in testosterone, growth hormone, and cortisol responses compared to traditional sets (TS) 1,3 . RR may allow for heavier loads due to lower blood lactate responses during exercise 4 . ...
... In particular, power output decrements observed across consecutive sets during the TRA protocol, may have been caused by an acute increase in metabolic stress. This hypothesis is in agreement with previous studies, in which traditional-set configurations similar to the one used in this study led to greater blood lactate concentration and the consequent inability to maintain optimal power outputs (Girman et al. 2014;González-Hernández et al. 2020;Gorostiaga et al. 2014Gorostiaga et al. , 2010. As a result, prescribing resistance training using cluster-set configurations with low repetition numbers may help to avoid these detrimental metabolic effects and provide a greater stimulus for power enhancement adaptations than resistance training using traditional-set configuration and clusters of many repetitions. ...
PurposeThe aims of this study were to compare mechanical outputs (i.e. power and impulse), physiological (i.e. heart rate) and perceptual (i.e. effort and fatigue) responses in older men to traditional-set or different cluster-set configuration resistance training protocols.Methods
In a randomized cross-over design, 20 healthy old men (aged 67.2 ± 2.1 years) completed four resistance training sessions using the back squat exercise loaded with optimal power loads. Training configurations were: traditional (TRA), three sets of six repetitions with 120-s rest between each set; Cluster-set 1 (CLU1), 24 single-repetition clusters with 10 s of rest after every cluster; Cluster-set 2 (CLU2), 12 double-repetition clusters with 20-s rest after every cluster; and Cluster-set 4 (CLU4), 6 quadruple-repetition clusters with 40-s rest after every cluster.ResultsCluster-set configurations resulted in greater power outputs compared to traditional-set configuration (range 2.6–9.2%, all p 0.07 for main effect and protocol set interactions). CLU1 and CLU2 induced higher heart rate (range 7.1–10.5%, all p < 0.001 for main effect and protocol set interactions), lower rating of perceived exertion (range − 1.3 to − 3.2 AU, all p 0.006 for pairwise comparisons) and lower ratings of fatigue (range − 0.15 to − 4 AU, all p 0.012 for pairwise comparisons) compared to TRA and CLU4. Finally, an absolute preference for CLU2 was reported.Conclusions
Findings presented here support the prescription of CLU2 as an optimal resistance training configuration for trained older men using the back squat.
... Our data demonstrated that the long set configuration produced higher lactate values in comparison with the shorter one. Similar results were observed in previous studies, where sets with a continuous pattern promoted greater lactate response than a work-equated set with an intra-set rest design (Goto et al. 2005;Girman et al. 2014) and a slower recovery to the baseline values (Denton and Cronin 2006). Mechanical responses during a long set configuration session (LSC, grey bars) and a short set configuration session (SSC, black bars) for the knee extension (KE), bench press (BPR) and parallel squat (SQ) exercises. ...
PurposeWe aimed to analyse the acute effects of set configuration on cardiac parasympathetic modulation and blood pressure (BP) after a whole-body resistance training (RT) session.Methods
Thirty-two participants (23 men and 9 women) performed one control (CON) and two RT sessions differing in the set configuration but with the same intensity (15RM load), volume (200 repetitions) and total resting time (360 s between sets for each exercise and 3 min between exercises): a long set configuration (LSC: 4 sets of 10 repetitions with 2 resting minutes) and a short set configuration session (SSC, 8 sets of 5 repetitions with 51 resting seconds). Heart rate variability, baroreflex sensitivity, the low frequency of systolic blood pressure oscillations (LFSBP), BP and lactatemia were evaluated before and after the sessions and mechanical performance was evaluated during exercise.ResultsLSC induced greater reductions on cardiac parasympathetic modulation versus SSC after the session and the CON (p < 0.001 to p = 0.024). However, no LFSBP and BP significant changes were observed. Furthermore, LSC caused a higher lactate production (p < 0.001) and velocity loss (p ≤ 0.001) in comparison with SSC.Conclusion
These findings suggest that SSC attenuates the reduction of cardiac parasympathetic modulation after a whole-body RT, improving the mechanical performance and decreasing the glycolytic involvement, without alterations regarding vascular tone and BP.
... Although many studies show that movement velocity and power output can be maintained across a variety of exercises using basic cluster sets (García-Ramos et al. 2015;Haff et al. 2003;Hardee et al. 2012a;Tufano et al. 2016a;Tufano et al. 2016b;Valverde-Esteve et al. 2013), mechanistic exploration of these cluster sets is less common (Girman et al. 2014;Morales-Artacho et al. 2018), and the effects of different exercises have not been examined within the same study. ...
This study investigated redistributing long inter-set rest intervals into shorter but more frequent intervals at 2 different concentric velocities. Resistance-trained men performed 4 randomised isokinetic unilateral knee extension protocols, 2 at 60°·s⁻¹ and 2 at 360°·s⁻¹. At each speed, subjects performed 40 repetitions with 285 s of rest using traditional sets (TS; 4 sets of 10 with 95 s of inter-set rest) and rest-redistribution (RR; 20 sets of 2 with 15 s inter-set rest). Before and at 2, 5, and 10 min after exercise, tensiomyography (TMG) and oxygenation (near-infrared spectroscopy; NIRS) were measured. NIRS was also measured during exercise, and rating of perceived exertion (RPE) was recorded after every 10 repetitions. At both speeds, RR displayed greater peak torque, total work, and power output during latter repetitions, but there were no differences between TS or RR when averaging all 40 repetitions. The RPE was less during RR at both speeds (p < 0.05). RR increased select muscle oxygen saturation and blood flow at both speeds. There were no effects of protocol on TMG, but effect sizes favoured a quicker recovery after RR. RR was likely beneficial in maintaining performance compared with the latter parts of TS sets and limiting perceived and peripheral fatigue.
NoveltyAlthough effective at slow velocities, rest-redistribution was likely more effective during high-velocity movements in this study.
Rest-redistribution maintained the ability to produce force throughout an entire range of motion.
Rest-redistribution reduced RPE during both high-velocity and high-force movements.
... The development of strength and power can be optimized through proper management of acute training variables such as sets, reps, rest periods, and exercise order [2]. However, greater degrees of variation and novelty of stimulus are required to continue to drive changes in athletes with an advanced training status [3,4]. Novelty and variation must be systematically planned, sequenced, and with consideration of the multi-faceted nature of the demands of sporting actions. ...
The current investigation was an examination of the repetition-to-repetition magnitudes and changes in kinetic and kinematic characteristics of the back squat using accentuated eccentric loading (AEL) and cluster sets. Trained male subjects (age = 26.1 ± 4.1 years, height = 183.5 ± 4.3 cm, body mass = 92.5 ± 10.5 kg, back squat to body mass ratio = 1.8 ± 0.3) completed four load condition sessions, each consisting of three sets of five repetitions of either traditionally loaded straight sets (TL), traditionally loaded cluster sets (TLC), AEL cluster sets (AEC), and AEL straight sets where only the initial repetition had eccentric overload (AEL1). Eccentric overload was applied using weight releasers, creating a total eccentric load equivalent to 105% of concentric one repetition maximum (1RM). Concentric load was 80% 1RM for all load conditions. Using straight sets (TL and AEL1) tended to decrease peak power (PP) (d = −1.90 to −0.76), concentric rate of force development (RFDCON) (d = −1.59 to −0.27), and average velocity (MV) (d = −3.91 to −1.29), with moderate decreases in MV using cluster sets (d = −0.81 to −0.62). Greater magnitude eccentric rate of force development (RFDECC) was observed using AEC at repetition three (R3) and five (R5) compared to all load conditions (d = 0.21⁻0.65). Large within-condition changes in RFDECC from repetition one to repetition three (∆REP1⁻3) were present using AEL1 (d = 1.51), demonstrating that RFDECC remained elevated for at least three repetitions despite overload only present on the initial repetition. Overall, cluster sets appear to permit higher magnitude and improved maintenance of concentric outputs throughout a set. Eccentric overload with the loading protocol used in the current study does not appear to potentiate concentric output regardless of set configuration but may cause greater RFDECC compared to traditional loading.
... With traditional sets of 5 to 10 repetitions there is a progressive decrease in PCr stores and a concomitant rise in lactate accumulation (Gorostiaga et al. 2012). The introduction of a 10-30-s interrepetition or intra-set rest interval has been suggested to result in a lower acute lactate response (Girman et al. 2014), which may result in alterations in acute hormonal responses to a training bout that contains cluster sets (Oliver et al. 2015). In one of the few studies examining the acute hormonal responses to cluster sets, Oliver et al. (2015) report that cluster sets result in a significantly lower lactate, growth hormone, and cortisol response pattern. ...
The primary purpose of this investigation was to determine the impact of altering the set structure during an 8-week resistance training program on anthropometric, hormonal, and strength power characteristics. Thirty female volleyball players were recruited for participation and then randomly assigned to 1 of 3 resistance training groups: (i) cluster sets (CRT; n = 10), (ii) traditional sets (TRT; n = 10), or (iii) control (CON; n = 10). All athletes were evaluated for thigh and arm circumference, vertical jump, 20-m sprint, 4 × 9-m shuttle-run, 1-repetition maximum (1RM) back squat, bench press, military press, and deadlift prior to and after an 8-week periodized training intervention. Blood samples were taken before and after the 8-week training period to evaluate resting testosterone, cortisol, and insulin-like growth factor 1 responses to the training period. After 8 weeks of training the CRT group displayed a small but significant improvement in vertical jump (CRT: effect size (ES) = 038, 7.1%) performance when compared with the TRT group (ES = 0.34, 5.6%). Both the CRT and TRT training interventions resulted in very large increases in the 1RM squat (CRT: 8.4% ± 1.2%; TRT: 7.3% ± 0.6%), bench press (CRT: 8.3% ± 2.0%; TRT: 8.7% ± 1.9%), military press (CRT: 5.7% ± 1.2%; TRT: 5.5% ± 1.6%), and deadlift (CRT: 8.2% ± 1.6%; TRT: 8.3% ± 2.2%). There were no significant differences in 20-m sprint or 4 × 9-m shuttle run times between the CRT, TRT, and CON groups. These results suggest that cluster sets allow for greater improvements in vertical jump performance and equal improvements in strength gains to those seen with traditional sets.
... force, movement velocity, and power output) better than traditional sets which contain no intra-set rest (Hardee et al., 2012;Tufano et al., 2016b). Since intra-set rest periods allow for the replenishment of immediate energy stores, the removal of metabolic byproducts from the muscle, and the maintenance of acute performance (Girman et al., 2014;Oliver et al., 2015), cluster sets have been used to perform high volumes of external work without resulting in greater acute neuromuscular fatigue (Joy et al., 2013;Oliver et al., 2015;Tufano et al., 2016b) in a variety of exercises and populations (Asadi and Ramirez-Campillo, 2016;Iglesias-Soler et al., 2013). ...
Eight resistance-trained men completed three protocols separated by 48-96 hours. Each protocol included 36 repetitions with the same rest duration, but the frequency and length of rest periods differed. The cluster sets of four (CS4) protocol included 30 s of rest after the 4th, 8th, 16th, 20th, 28th, and 32nd repetition in addition to 120 s of rest after the 12th and 24th repetition. For the other two protocols, the total 420 s rest time of CS4 was redistributed to include nine sets of four repetitions (RR4) with 52.5 s of rest after every four repetitions, or 36 sets of single repetitions (RR1) with 12 s of rest after every repetition. Mean (MF) and peak (PF) force, velocity (MV and PV), and power output (MP and PP) were measured during 36 repetitions and were collapsed into 12 repetitions for analysis. Repeated measures ANOVA 3 (protocol) x 12 (repetition) showed a protocol x repetition interaction for PF, MV, PV, MP, and PP (p-values from <0.001 to 0.012). No interaction or main effect was present for MF. During RR1, MV, PV, MP, and PP were maintained, but decreased throughout every 4-repetition sequence during CS4 and RR4. During CS4 and RR4, PF was less following a rest period compared to subsequent repetitions, whereas PF was maintained during RR1. These data indicate that rest redistribution results in similar average kinetics and kinematics, but if total rest time is redistributed to create shorter but more frequent sets, kinetics and kinematics may remain more constant.
... In contrast to traditional set configurations (TRD), which result in an almost linear decrease in force [9,24], velocity [9,24], and power [9,16,23], CLU maintain and/or attenuate the loss in power [9,16,23], primarily due to higher velocities [24]. This is facilitated by the ability of the phosphagen and glycolytic energy systems to recover during the brief rest periods as evidenced by lower blood lactate [5,6,23] following CLU compared to TRD, as well as greater intramuscular adenosine triphosphate (ATP) and phosphocreatine (PCr) [6]. However, although the beneficial effects of CLU in the acute setting are unequivocal [9,16,24], long-term studies have failed to produce results superior to TRD [8,33], except when training was performed at or around the optimal load [22]. ...
This study compared the acute cytokine response, and kinetic and kinematic profile following back squat exercise in resistance-trained men. In a randomized, cross-over design, 10 resistance-trained men (27±4 y, 1.80±0.07 m, 82.8±6.7 kg, 16.3±3.5% fat) performed the back squat exercise using traditional and cluster set configurations. Kinetic and kinematic data were sampled throughout each condition. Venous blood was sampled prior, immediately post, 30 min, 60 min, 24 h, and 48 h post-exercise for plasma interleukin-6 (IL-6) and interleukin-15 (IL-15). Cluster sets allowed for greater mean power (mean difference, 110 W; 90% confidence interval, ±63 W; benefit odds, 41 447:1), driven by higher overall mean velocities (0.053 m∙s⁻¹; 0.039 m∙s⁻¹; 3 105:1) as evidenced by the lack of clear contrasts for mean force. IL-15 increased post-exercise in both conditions, but increased at 24 h (0.13 pg·mL⁻¹; ±0.11 pg·mL⁻¹; 486:1) and 48 h (0.12 pg·mL⁻¹; ±0.10 pg·mL⁻¹; 667:1) in traditional sets only. IL-6 increased similarly in both conditions, post-exercise through 60 min post. Cluster set configurations allow for greater mean power, attributed to higher velocities. Despite a similar response of IL-6, traditional set configuration may provide a greater stimulus for hypertrophy as evidenced by a secondary increase in IL-15.
© Georg Thieme Verlag KG Stuttgart · New York.
... Since our participants did not reach muscular failure, resulting in less velocity-and powerbased fatigue when compared to other studies, 9,11,14 practical resistance training recommendations may be drawn from the data presented and used in situations where repeatedly training to failure may be unwarranted. 27,28 Lastly, some studies have failed to report individual repetition data, 20,22,29 collapsed variables across sets, 2,23,30 changed the load during the protocol, 16,26 and collapsed variables between protocols 23 making direct comparisons between studies rather difficult. Therefore, percent decline variables were reported in this discussion for the sake of keeping comparisons consistent. ...
Purpose:
The purpose of this investigation was to compare the effects of a traditional set structure and two cluster set structures on force, velocity, and power during back squats in strength-trained men.
Methods:
Twelve men (25.8 ± 5.1 y; 1.74 ± 0.07 m; 79.3 ± 8.2 kg) performed three sets of twelve repetitions at 60% of one repetition maximum using three different set structures: traditional sets (TS), cluster sets of four (CS4), and cluster sets of two (CS2).
Results:
When averaged across all repetitions, peak velocity (PV), mean velocity (MV), peak power (PP), and mean power (MP) were greater in CS2 and CS4 compared to TS (p < 0.01), with CS2 also resulting in greater values than CS4 (p < 0.02). When examining individual sets within each set structure, PV, MV, PP, and MP decreased during the course of TS (effect sizes range from 0.28 - 0.99), while no decreases were noted during CS2 (effect sizes range from 0.00 - 0.13) or CS4 (effect sizes range from 0.00 - 0.29).
Conclusions:
These results demonstrate that CS structures maintain velocity and power whereas TS structures do not. Furthermore, increasing the frequency of intra-set rest intervals in CS structures maximises this effect and should be used if maximal velocity is to be maintained during training.
The purpose of this study was to investigate the role of set structures in designing bodyweight power training (BWPT). Specifically, we compared the effects of the cluster set structure undulating variant (CSS UV) and the traditional set structure (TSS) on training load and performance during vertical jumping sessions. Sixteen active males participated in this study. We designed four training sessions that consisted of 144 countermovement jumps distributed into 12 sets, where the number of repetitions varied for the CSS UV sessions, whereas for TSS sessions the number of repetitions was fixed. In addition, both of the applied set structures included sessions with short (60 seconds) and long rest periods (120 seconds), while training volume was separately analysed for the first six sets (small volume) and the last six sets (large volume). External load, internal load, and performance variables were calculated. The results suggest that CSS UV allows superior utilization of applied external load, reduction of internal load and overall higher performances that are maintained during entire training session compared to TSS (p<.05). The present study provides important findings about advantages of CSS UV over TSS in terms of external load, internal load, and performances during vertical jumping sessions, and therefore, it might be more suitable approach to designing BWPT.
Çalışmanın amacı, güreşçilerde Geleneksel Setleme (GS) yöntemi ve Cluster Setleme (CS) yöntemi ile oluşturulmuş Post Aktivasyon Potansiyeli (PAP) protokolünün dikey sıçrama ve anaerobik performans üzerine etkisini incelemektir. Araştırmaya branşında 5,00±0,86 yıllık spor geçmişine sahip toplam 17 gönüllü erkek güreşçi katılmıştır. Sporcular tesadüfi yöntemle GS ve CS grup olarak ikiye ayrılmıştır. Araştırma 24 saat aralıkla 3 oturumdan oluşmuştur. İlk oturumda sporcuların 1 TM yükleri belirlenmiş, ikinci oturumda sporculara ön test Counter Movement Jump (CMJ) testi uygulanmıştır. Son oturumda GS grubundaki sporcular %85 (1-TM) 2x8 tekrar squat hareketini (set arası 210 sn dinlenmeler), CS grubundaki sporcular ise %85 (1-TM) 8x2 tekrar squat hareketini (set arası 30 sn dinlenmeler) uyguladıktan sonra her iki grup 2 dk dinlenme sonrası son test CMJ testi uygulamıştır. Gruplar normal dağılım gösterdiği için grup içi ön test-son test farklılığını belirlemek amacıyla Eşleştirilmiş Örneklem t test, gruplar arası CS-GS farklılığını belirlemek için de Bağımsız Örneklemler t testi kullanılmıştır. CS ve GS yöntemlerinde gruplar arası anlamlı bir farklılık bulunamamıştır. Grup içi karşılaştırmalarda da GS yöntemde anlamlı bir farklılık bulunmazken, CS yöntemi uygulayan sporcuların dikey sıçrama, ortalama ve nispi anaerobik güç parametrelerinde anlamlı bir farklılık bulunmuştur (p<0,05). CS yöntemi dikey sıçramayı %11,65, ortalama anaerobik gücü %6,18 ve nispi anaerobik gücü %6,58 oranında geliştirirken GS yönteminde oransal olarak gelişim bulunamamıştır. CS ve GS arasında fark olmamasına rağmen güreşçilere CS yöntemiyle uygulanan olan kuvvet antrenmanlarının, GS yöntemiyle uygulanan kuvvet antrenmanlarına göre dikey sıçrama ve anaerobik güç çıktılarını daha yüksek düzeyde geliştirdiği söylenebilir.
Altering set configurations during a resistance training program can provide a novel training variation that can be used to modify the external and internal training loads that induce specific training outcomes. To design training programs that better target the defined goal(s) of a specific training phase, strength and conditioning professionals need to better understand how different set configurations impact the training adaptations that result from resistance training. Traditional and cluster set structures are commonly implemented by strength and conditioning. The purpose of this review is to offer examples of the practical implementation of traditional and cluster sets that can be integrated into a periodized resistance training program.
Context
The Nordic hamstring exercise (NHE) is known to reduce hamstrings injury (HIS) risk in athletes. In order to optimise the NHE it is important to understand how acute resistance training variables influence its performance.
Objective
To examine the effects of different inter-set rest intervals (ISRI) on force indices during performance of the NHE. Design: Crossover Study.
Setting
Laboratory based.
Patients or Participants
Ten (age = 20.7 ± 2.3 years; height = 179.4 ± 5.5 cm; body mass = 83.9 ± 12.4 kg) well-trained young male team-sport athletes.
Intervention
Participants performed 2 x 6 repetitions of the NHE with either a SHORT (one-minute) or LONG (three-minute) ISRI. All sets were performed on the NordBord.
Main Outcomes Measure(s)
Peak force (N), average force (N), percent maintenance (%) and percent decline (%) were recorded for both dominant and non-dominant limbs as well as inter-limb force asymmetries (%) calculated.
Results
Analyses revealed no statistically significant interactions or main effects (p > 0.05) between conditions and sets in all variables. However, analysis of individual repetitions showed significant reductions (p < 0.05, ES = 0.58–1.28) in peak force from repetition four onwards.
Conclusions
Our findings suggest that a one-minute ISRI is sufficient to maintain force production qualities and inter-limb asymmetries between sets during the NHE in well-trained athletes. However, practitioners should be aware of the potentially high decrements in peak force production that may occur within the set.
The appropriate dosage of resistance training exercises helps to promotes physical and physiological adaptations and decrease injuries. The aim of the study was to analyze the effects of the different intra-set rest after eight weeks of resistance training on morphological variables, maximal strength, and jump performance in physically active university students. Twenty-five students (15 men and 10 women) were randomized by sex and distributed in Control Group (CG) (n=8) with rest only at the end of the series;
Experimental Group 1 (EG1) (n=9) with an intra-set rest of 30 s, and Experimental Group 2 (EG2) (n=8) with four intra-set rest of 10 s. Morphological variables [body weight, bipedal height, body mass index (BMI), fat mass and muscle mass], maximum upper body strength (bench press and military press), lower body strength [parallel squat (45°) and deadlift], as well as countermovement jump (CMJ) were measured. All three groups obtained a significant increase (p<0.01) in body weight and BMI, as well as an essential reduction (p<0.01) of fat mass. Muscle mass increased significantly (p<0.01) for both CG and EG1. Maximum upper- and lower-body strength increased considerably (p<0.05) across all three groups and for all exercises, while the CMJ notably increased for CG and EG1. There are no significant changes between the different intra-set rest, when using the same volume, intensity, and total recovery time during the exercise series; thereby, there
is an equivalent increase in muscle mass, maximal strength, jump performance, as well as a fat mass reduction.
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 XX(X): 000-000, 2018-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, η G < 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, η G = 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.
A priority in strength and power exercise might be to train with as high quality as possible for the shortest possible duration. In this context, peak power output could reflect quality. Designing an exercise session as a cluster set structure, as compared to a traditional set structure, may be a way to obtain higher peak power output in the session. But it is unknown whether that is obtainable for non-elite individuals performing loaded jump squat exercise. The aim of the present study was therefore to test the hypothesis that peak power output would be highest in a jump squat exercise session, which was structured with cluster sets, as compared to traditional sets. Ten individuals (2 women, 8 men; 26.5 ± 4.8 years, 1.81 ± 0.08 m, 90.9 ± 13.2 kg) performed two loaded jump squat exercise sessions structured with cluster sets and traditional sets, respectively. The sessions were performed on two separate days, in counterbalanced order. The position of the barbell was used to calculate derived values including peak power output. Values calculated as averages across the entire exercise sessions showed peak power output to be 178 ± 181 W, corresponding to 4.1% ± 4.9%, higher in the session with cluster set structure, as compared to the session with traditional set structure (p = 0.005). It was concluded that for non-elite individuals, peak power output was approximately 4% higher in a loaded jump squat exercise session structured with cluster sets as compared to an exercise session structured with traditional sets.
This study aimed to compare mechanical, metabolic, and perceptual responses between two traditional (TR) and four cluster (CL) set configurations. In a counterbalanced randomized order, 11 men were tested with the following protocols in separate sessions (sets × repetitions [inter-repetition rest]): TR1: 3×10 [0-s]; TR2: 6×5 [0-s]; CL1: 3×10 [10-s]; CL2: 3×10 [15-s]; CL3: 3×10 [30-s]); CL4: 1×30 [15-s]). The exercise (full-squat), number of repetitions (30), inter-set rest (5 min), and resistance applied (10RM) was the same for all set configurations. Mechanical fatigue was quantified by measuring the mean propulsive velocity during each repetition, and the change in countermovement jump height observed after each set and after the whole training session. Metabolic and perceptual fatigue were assessed via the blood lactate concentration and the OMNI perceived exertion scale measured after each training set, respectively. The mechanical, metabolic, and perceptual measures of fatigue were always significantly higher for the TR1 set configuration. The two set configurations that most minimized the mechanical measures of fatigue were CL2 and CL3. Perceived fatigue did not differ between the TR2, CL1, CL2 and CL3 set configurations. The lowest lactate concentration was observed in the CL3 set configuration. Therefore, both the CL2 and CL3 set configurations can be recommended because they maximize mechanical performance. However, the CL2 set configuration presents two main advantages with respect to CL3: (1) it reduces training session duration, and (2) it promotes higher metabolic stress, which to some extent may be beneficial for inducing muscle strength and hypertrophy gains.
Morales-Artacho, AJ, Padial, P, García-Ramos, A, Pérez-Castilla, A, and Feriche, B. Influence of a cluster set configuration on the adaptations to short-term power training. J Strength Cond Res 32(4): 930-937, 2018-This study investigated the effects of a traditional (TT) vs. cluster (CT) resistance training on the lower-body force, velocity, and power output. Nineteen males were allocated to a CT or a TT group and took part of a 3-week resistance training (2 weekly sessions). CT involved 6 sets of 3 × 2 repetitions (30 seconds rest every 2 repetitions and 4 minutes 30 seconds between sets). TT comprised 6 sets of 6 continuous repetitions (5 minutes rest between sets). Before and after the training period, force (F25, F50, F75), velocity (V25, V50, V75), and power (P25, P50, P75) were obtained during the countermovement jump (CMJ) exercise at 3 external loading conditions (25, 50, and 75% of body mass). Individual linear regressions were used to determine the force-velocity profile including the Slope, estimated maximal theoretical force (F0), velocity (V0), and power (P0). After CT, very-likely moderate increments in P25 were observed compared with TT (p = 0.011, ES = 0.55) because of a very-likely moderate rise in V25 (p = 0.001, ES = 0.71). No significant differences were observed in any of the F-v profile variables between the TT and CT groups (p ≥ 0.207, ES ≤ 0.31). Our results suggest that 3 weeks of muscle power training including cluster set configurations are more efficient at inducing velocity and power adaptations specific to the training load.
The purpose of this study was to compare the kinematic, metabolic, endocrine, and perceptual responses of three back squat protocols with equal loads, number of repetitions, and total rest duration. Eight strength-trained men performed 36 back squats using 75% 1RM and 420 s of total rest during basic cluster sets of 4 (CS4), rest-redistribution sets of 4 (RR4), and rest-redistribution sets of 1 (RR1). Ratings of perceived exertion (RPE), blood lactate (La), mean velocity maintenance (MVM), and mean velocity loss (MVL) were measured during exercise. Total testosterone (TT), growth hormone (GH), cortisol (C), and sex-hormone binding globulin (SHBG) were measured before exercise and 15, 30, and 60 min post-exercise. There were no differences between protocols for MVM. However, MVL was less during RR1 compared to RR4 (p=0.032), and neither protocol was different than CS4. All protocols resulted in similar increases in RPE and La, which remained elevated up to 30 min post-exercise (p<0.05). In all protocols, GH increased and returned to baseline by 60 min post-exercise (p<0.05). At 60 min post-exercise, TT was less than all other time points (p<0.05). There were no main effects for time for SHBG or C. The data from this study show that different types of cluster set protocols can result in pro-anabolic physiological responses to resistance training. Additionally, coaches can redistribute rest periods without affecting perceived effort or metabolic and hormonal changes if the external load, number of repetitions, and total rest time are equalized.
The endocrine system plays an important role in strength and power development by mediating the remodelling of muscle protein. Resistance training scheme design regulates muscle protein turnover by modifying the anabolic (testosterone, growth hormone) and catabolic (cortisol) responses to a workout. Although resistance exercise increases the concentrations of insulin-like growth factor 1 in blood following exercise, the effect of scheme design is less clear, most likely due to the different release mechanisms of this growth factor (liver vs muscle). Insulin is non-responsive to the exercise stimulus, but in the presence of appropriate nutritional intake, elevated blood insulin levels combined with resistance exercise promotes protein anabolism. Factors such as sex, age, training status and nutrition also impact upon the acute hormonal environment and, hence, the adaptive response to resistance training. However, gaps within research, as well as inconsistent findings, limit our understanding of the endocrine contribution to adaptation. Research interpretation is also difficult due to problems with experimental design (e.g. sampling errors) and various other issues (e.g. hormone rhythms, biological fluid examined). In addition to the hormonal responses to resistance exercise, the contribution of other acute training factors, particularly those relating to the mechanical stimulus (e.g. forces, work, time under tension) must also be appreciated. Enhancing our understanding in these areas would also improve the prescription of resistance training for stimulating strength and power adaptation.
The ability to stimulate specific physiological and performance adaptations is in large part predicated by the ability to vary the training stimuli and induce novel stimuli at appropriate times. One new method for introducing training variation, while maximizing the velocity and power output of the training exercise is the utilization of a cluster set configuration. This review takes the theoretical and scientific foundation about the use of the cluster set and offers examples of how this unique training tool can be applied to the preparation of athletes from various sports.
of very short rest periods on hormonal responses to resistance exercise in men. J Strength Cond Res 24(7): 1851–1859, 2010—The effect of 3 different rest periods on the acute hormonal responses to resistance exercise (RE) was examined in 10 experienced resistance trained men (age: 20.37 6 2.24 years, weight: 65.5 6 26.70 kg). On 3 separate sessions of an RE protocol, subjects were assigned in a random order a rest interval of 60 seconds (P60), 90 seconds (P90), or 120 seconds (P120) between sets. The RE session consisted of 4 sets of squat and bench press to failure using 85% of 1 repetition maximum. Blood draws occurred at pre-exercise (T0), immediately post (T1), and 30 minutes post (T30) exercise for measurement of serum growth hormone (GH), testosterone (TS), and blood-lactate concentrations. Serum GH concen-trations were significantly higher at T1 in P60 (64%) compared with P120. Also, serum TS concentrations were significantly higher at T1 in P120 (65%) and P90 (76%) compared to P60 (p # 0.05). Blood-lactate concentrations significantly increased at T1 for 3 protocols, but no significant protocols differences were observed. Although, training volume by using P90 and P120 was greater than that of P60, statistically a significant difference in training volume was not observed. The results of the present study support rest period in RE sets as an important variable to increase the anabolic hormone concentrations, and it should be mentioned that short rest intervals elevated greater increase in GH concentration compared with 120-second rest. However, TS response was greater in the RE protocol with a 120-second rest interval between sets.
The purpose of this study was to compare acute mechanical and metabolic effects of 2 sessions of resistance training equated by volume and total resting time but with different set configuration: sets to failure (FS) vs. distribution of rest between each repetition (NFS). 10 male judoists completed a session consisting of 3 sets to failure of parallel back squat with 4 repetitions at maximum load, and a rest of 3 min between the sets. At least 72 h later subjects developed the same volume, but total resting time was distributed among individual repetitions. Before and after sessions isometric force and mean propulsive velocity with load corresponding to maximum propulsive power were assessed. Results showed that in respect to FS, NFS showed an 18.94% (±17.98) higher average mean propulsive velocity during session (0.42±0.04 vs. 0.35±0.08 m.s - 1; p=0.009), lower blood lactate concentration after session (maximum average value 1.52±0.77 vs. 3.95±1.82; session effect: p=0.001) and higher mean propulsive velocity with load corresponding to maximum propulsive power (mean propulsive velocity immediately after session 0.64±0.09 vs. 0.59±0.12 m.s - 1; session effect: p=0.019). These data show that distribution of rest in sessions equated for volume and total resting time determines differences in performance during sessions and mechanical or metabolic acute effects.
The purpose of this study was to analyze the influence of exercise type, set configuration, and relative intensity load on relationship between 1 repetition maximum (1RM) and maximum number of repetitions (MNR). Thirteen male subjects, experienced in resistance training, were tested in bench press and biceps curl for 1RM, MNR at 90% of 1RM with cluster set configuration (rest of 30s between repetitions) and MNR at 70% of 1RM with traditional set configuration (no rest between repetitions). A lineal encoder was used for measuring displacement of load. Analysis of variance analysis revealed a significant effect of load (p<0.01) and a tendency in exercise factor (p=0.096), whereas the interaction effect was not significant. MNR at 70% of 1RM was lower for biceps curl (16.31+/-2.59 vs. 8.77+/-3 in bench press and biceps curl, respectively; p<0.05) and at 90% of 1RM (21.85+/-11.06 vs. 18.54+/-12.84 in bench press and biceps curl, respectively; p>0.05). Correlation between 1RM and MNR was significant for medium-intensity in biceps curl (r=-0.574; p<0.05) and between MNR and 1RM/body mass (r=-0.574; p<0.05). Neither 1RM nor 1RM/body mass correlated with velocity along set, so velocity seems to be similar at a same relative intensity for subjects with differences in maximum strength levels. From our results, we suggest the employment of MNR rather than % of 1RM for training monitoring. Furthermore, we suggest the introduction of cluster set configuration for upper-body assessment of MNR and for upper-body muscular endurance training at high-intensity loads, as it seems an efficient approach in looking for sessions with greater training volumes. This could be an interesting approach for such sports as wrestling or weightlifting.
Strength training has become one of the most popular physical activities for increasing characteristics such as absolute muscular strength, endurance, hypertrophy and muscular power. For efficient, safe and effective training, it is of utmost importance to understand the interaction among training variables, which might include the intensity, number of sets, rest interval between sets, exercise modality and velocity of muscle action. Research has indicated that the rest interval between sets is an important variable that affects both acute responses and chronic adaptations to resistance exercise programmes. The purpose of this review is to analyse and discuss the rest interval between sets for targeting specific training outcomes (e.g. absolute muscular strength, endurance, hypertrophy and muscular power). The Scielo, Science Citation Index, National Library of Medicine, MEDLINE, Scopus, Sport Discus and CINAHL databases were used to locate previous original scientific investigations. The 35 studies reviewed examined both acute responses and chronic adaptations, with rest interval length as the experimental variable. In terms of acute responses, a key finding was that when training with loads between 50% and 90% of one repetition maximum, 3-5 minutes' rest between sets allowed for greater repetitions over multiple sets. Furthermore, in terms of chronic adaptations, resting 3-5 minutes between sets produced greater increases in absolute strength, due to higher intensities and volumes of training. Similarly, higher levels of muscular power were demonstrated over multiple sets with 3 or 5 minutes versus 1 minute of rest between sets. Conversely, some experiments have demonstrated that when testing maximal strength, 1-minute rest intervals might be sufficient between repeated attempts; however, from a psychological and physiological standpoint, the inclusion of 3- to 5-minute rest intervals might be safer and more reliable. When the training goal is muscular hypertrophy, the combination of moderate-intensity sets with short rest intervals of 30-60 seconds might be most effective due to greater acute levels of growth hormone during such workouts. Finally, the research on rest interval length in relation to chronic muscular endurance adaptations is less clear. Training with short rest intervals (e.g. 20 seconds to 1 minute) resulted in higher repetition velocities during repeated submaximal muscle actions and also greater total torque during a high-intensity cycle test. Both of these findings indirectly demonstrated the benefits of utilizing short rest intervals for gains in muscular endurance. In summary, the rest interval between sets is an important variable that should receive more attention in resistance exercise prescription. When prescribed appropriately with other important prescriptive variables (i.e. volume and intensity), the amount of rest between sets can influence the efficiency, safety and ultimate effectiveness of a strength training programme.
To examine endogenous anabolic hormonal responses to two different types of heavy resistance exercise protocols (HREPs), eight male and eight female subjects performed two randomly assigned protocols (i.e. P-1 and P-2) on separate days. Each protocol consisted of eight identically ordered exercises carefully designed to control for load, rest period length, and total work (J) effects. P-1 utilized a 5 RM load, 3-min rest periods and had lower total work than P-2. P-2 utilized a 10 RM load, 1-min rest periods and had a higher total work than P-1. Whole blood lactate and serum glucose, human growth hormone (hGH), testosterone (T), and somatomedin-C [SM-C] (i.e. insulin-like growth factor 1, IGF-1) were determined pre-exercise, mid-exercise (i.e. after 4 of the 8 exercises), and at 0, 5, 15, 30, and 60 min post-exercise. Males demonstrated significant (p less than 0.05) increases above rest in serum T values, and all serum concentrations were greater than corresponding female values. Growth hormone increases in both males and females following the P-2 HREP were significantly greater at all time points than corresponding P-1 values. Females exhibited significantly higher pre-exercise hGH levels compared to males. The P-1 exercise protocol did not result in any hGH increases in females. SM-C demonstrated random significant increases above rest in both males and females in response to both HREPs.(ABSTRACT TRUNCATED AT 250 WORDS)
To examine endogenous anabolic hormone and growth factor responses to various heavy resistance exercise protocols (HREPs), nine male subjects performed each of six randomly assigned HREPs, which consisted of identically ordered exercises carefully designed to control for load [5 vs. 10 repetitions maximum (RM)], rest period length (1 vs. 3 min), and total work effects. Serum human growth hormone (hGH), testosterone (T), somatomedin-C (SM-C), glucose, and whole blood lactate (HLa) concentrations were determined preexercise, midexercise (i.e., after 4 of 8 exercises), and at 0, 5, 15, 30, 60, 90, and 120 min postexercise. All HREPs produced significant (P less than 0.05) temporal increases in serum T concentrations, although the magnitude and time point of occurrence above resting values varied across HREPs. No differences were observed for T when integrated areas under the curve (AUCs) were compared. Although not all HREPs produced increases in serum hGH, the highest responses were observed consequent to the H10/1 exercise protocol (high total work, 1 min rest, 10-RM load) for both temporal and time integrated (AUC) responses. The pattern of SM-C increases varied among HREPs and did not consistently follow hGH changes. Whereas temporal changes were observed, no integrated time (AUC) differences between exercise protocols occurred. These data indicate that the release patterns (temporal or time integrated) observed are complex functions of the type of HREPs utilized and the physiological mechanisms involved with determining peripheral circulatory concentrations (e.g., clearance rates, transport, receptor binding). All HREPs may not affect muscle and connective tissue growth in the same manner because of possible differences in hormonal and growth factor release.
The purpose of this research was to compare the effects of continuous repetition and intra-set rest training on maximal strength and power output of the upper body.
The 6 repetition maximum (6RM) and bench press throw power output against masses of 20, 30 and 40 kg of 26 elite junior male basketball and soccer players were tested on 2 separate occasions for reliability purposes. Subjects were then randomly assigned to either a continuous repetition (CR - 4 sets x 6 repetitions) or intra-set rest (ISR - 8 sets x 3 repetitions) training regime over 6-weeks. Volume (sets x repetitions x %6RM) between groups was equated and both groups completed all sets in the same time period (13 minutes and 20 seconds). The total concentric work time was determined to identify differences in training regimes. Independent sample t-tests on preintervention and postintervention percentage change scores were analysed for significant differences (p<0.05).
The observed coefficients of variation (1.7% to 4.8%) and intraclass correlation coefficients (r=0.87 to 0.98) indicated stability of these measures across testing occasions. The CR group significantly increased 6RM strength (9.7%) compared with the ISR group (4.9%). The total concentric work time was significantly longer in CR training than ISR (36.03+/- 4.03 s and 31.74+/-4.71 s; p=0.13). Power output increases across the 20, 30 and 40 kg loads ranged from 5.8% to 10.9% for both training groups but the between-group percentage change scores were not significantly different.
Bench press training involving 4 sets of 6 continuous repetitions elicited a greater improvement in bench press strength than 8 sets of 3 repetitions at the same percentage load of their 6RM. Both ISR and CR training were equally effective in increasing power output.
It has been proposed that, when learning a motor skill, individuals initially freeze degrees of freedom to simplify control. There is limited empirical evidence to support this proposition. We examined this issue by monitoring the performance of a non-skilled individual learning a soccer chip shot with his non-dominant leg over 9 days of practice (425 trials). Principal component analysis was used to examine dimensional change. The most dramatic change occurred at the hip, with the range of motion decreasing during the first 5 days of practice and then increasing thereafter. A reverse pattern was observed at the knee and ankle. While showing a progression in control from proximal to distal, a further phase was observed where primary control was passed back to the hip. The degree of linear coupling between the joints also increased with practice until day 5, after which independent control was observed. The number of controlled dimensions did not change across practice. Radial error decreased over practice and kinematics relating to the hip were most predictive of error, especially early in practice. Freezing degrees of freedom was a strategy implemented across the first half of practice, after which point-independent control was gradually restored enabling successful consistent performance.
The purpose of this study was to determine the change in weight training repetition power output as a consequence of interrepetition rest intervals. Twenty-six elite junior male basketball and soccer players performed bench presses using a 6 repetition maximum (6RM) load. The power output for each repetition was recorded using a linear encoder sampling each 10 ms (100 Hz). Subjects were assigned to 1 of 3 intervention groups, differentiated by the arrangement of rest intervals within the 6 repetitions: 6 x 1 repetition with 20-second rest periods between each repetition (Singles); 3 x 2 repetitions with 50 seconds between each pair of repetitions (Doubles); or 2 x 3 repetitions with 100 seconds of rest between each 3 repetitions (Triples). A timer was used to ensure that the rest interval and duration to complete all interrepetition interventions was equated across groups (118 seconds). Significantly (p < 0.05) greater repetition power outputs (25-49%) were observed in the later repetitions (4-6) of the Singles, Doubles, and Triples loading schemes. Significantly greater total power output (21.6-25.1%) was observed for all interrepetition rest interventions when compared to traditional continuous 6RM total power output. No significant between-group differences were found (p = 0.96). We conclude that utilizing interrepetition rest intervals enables greater repetition and total power output in comparison to traditional loading parameters.
The endocrine system plays an important role in strength and power development by mediating the remodelling of muscle protein. Resistance training scheme design regulates muscle protein turnover by modifying the anabolic (testosterone, growth hormone) and catabolic (cortisol) responses to a workout. Although resistance exercise increases the concentrations of insulin-like growth factor 1 in blood following exercise, the effect of scheme design is less clear, most likely due to the different release mechanisms of this growth factor (liver vs muscle). Insulin is non-responsive to the exercise stimulus, but in the presence of appropriate nutritional intake, elevated blood insulin levels combined with resistance exercise promotes protein anabolism. Factors such as sex, age, training status and nutrition also impact upon the acute hormonal environment and, hence, the adaptive response to resistance training. However, gaps within research, as well as inconsistent findings, limit our understanding of the endocrine contribution to adaptation. Research interpretation is also difficult due to problems with experimental design (e.g. sampling errors) and various other issues (e.g. hormone rhythms, biological fluid examined). In addition to the hormonal responses to resistance exercise, the contribution of other acute training factors, particularly those relating to the mechanical stimulus (e.g. forces, work, time under tension) must also be appreciated. Enhancing our understanding in these areas would also improve the prescription of resistance training for stimulating strength and power adaptation.
The primary aim of this study was to determine reliability and factorial validity of squat (SJ) and countermovement jump (CMJ) tests. The secondary aim was to compare 3 popular methods for the estimation of vertical jumping height. Physical education students (n = 93) performed 7 explosive power tests: 5 different vertical jumps (Sargent jump, Abalakow's jump with arm swing and without arm swing, SJ, and CMJ) and 2 horizontal jumps (standing long jump and standing triple jump). The greatest reliability among all jumping tests (Cronbach's alpha = 0.97 and 0.98) had SJ and CMJ. The reliability alpha coefficients for other jumps were also high and varied between 0.93 and 0.96. Within-subject variation (CV) in jumping tests ranged between 2.4 and 4.6%, the values being lowest in both horizontal jumps and CMJ. Factor analysis resulted in the extraction of only 1 significant principal component, which explained 66.43% of the variance of all 7 jumping tests. Since all jumping tests had high correlation coefficients with the principal component (r = 0.76-0.87), it was interpreted as the explosive power factor. The CMJ test showed the highest relationship with the explosive power factor (r = 0.87), that is, the greatest factorial validity. Other jumping tests had lower but relatively homogeneous correlation with the explosive power factor extracted. Based on the results of this study, it can be concluded that CMJ and SJ, measured by means of contact mat and digital timer, are the most reliable and valid field tests for the estimation of explosive power of the lower limbs in physically active men.
Acute and long-term hormonal and neuromuscular adaptations to hypertrophic strength training were studied in 13 recreationally strength-trained men. The experimental design comprised a 6-month hypertrophic strength-training period including 2 separate 3-month training periods with the crossover design, a training protocol of short rest (SR, 2 minutes) as compared with long rest (LR, 5 minutes) between the sets. Basal hormonal concentrations of serum total testosterone (T), free testosterone (FT), and cortisol (C), maximal isometric strength of the leg extensors, right leg 1 repetition maximum (1RM), dietary analysis, and muscle cross-sectional area (CSA) of the quadriceps femoris by magnetic resonance imaging (MRI) were measured at months 0, 3, and 6. The 2 hypertrophic training protocols used in training for the leg extensors (leg presses and squats with 10RM sets) were also examined in the laboratory conditions at months 0, 3, and 6. The exercise protocols were similar with regard to the total volume of work (loads 3 sets 3 reps), but differed with regard to the intensity and the length of rest between the sets (higher intensity and longer rest of 5 minutes vs. somewhat lower intensity but shorter rest of 2 minutes). Before and immediately after the protocols, maximal isometric force and electro-myographic (EMG) activity of the leg extensors were measured and blood samples were drawn for determination of serum T, FT, C, and growth hormone (GH) concentrations and blood lactate. Both protocols before the experimental training period (month 0) led to large acute increases (p < 0.05-0.001) in serum T, FT, C < and GH concentrations, as well as to large acute decreases (p < 0.05-0.001) in maximal isometric force and EMG activity. However, no significant differences were observed between the protocols. Significant increases of 7% in maximal isometric force, 16% in the right leg 1RM, and 4% in the muscle CSA of the quadriceps femoris were observed during the 6-month strength-training period. However, both 3-month training periods performed with either the longer or the shorter rest periods between the sets resulted in similar gains in muscle mass and strength. No statistically significant changes were observed in basal hormone concentrations or in the profiles of acute hormonal responses during the entire 6-month experimental training period. The present study indicated that, within typical hypertrophic strength-training protocols used in the present study, the length of the recovery times between the sets (2 vs. 5 minutes) did not have an influence on the magnitude of acute hormonal and neuromuscular responses or long-term training adaptations in muscle strength and mass in previously strength-trained men.
RELATIVELY FEW STUDIES HAVE BEEN CONDUCTED TO DETERMINE THE EFFECT OF DIFFERENT REST INTERVALS BETWEEN RESISTANCE EXERCISE SETS. A REST INTERVAL IS ESSENTIAL TO RE-ESTABLISH INTRA MUSCULAR BLOOD FLOW AND OXYGEN DELIVERY THAT ALLOWS FOR THE REPLENISHMENT OF PHOSPHOCREATINE STORES, RESTORATION OF INTRAMUSCULAR PH, REMOVAL OF METABOLIC END PRODUCTS, AND RETURN OF MUSCLE MEMBRANE POTENTIAL TO RESTING LEVELS. GENERAL RECOMMENDATIONS FOR REST INTERVAL LENGTH HAVE BEEN BASED PRIMARILY ON THE TRAINING GOAL (E.G., POWER, STRENGTH, HYPERTROPHY, MUSCULAR ENDURANCE). HOWEVER, OTHER FACTORS RELATED TO THE WORKOUT AND INDIVIDUAL CHARACTERISTICS MAY SHORTEN OR LENGTHEN THESE GENERAL RECOMMENDATIONS.
PERIODIZATION REPRESENTS AN OPTIMAL STRATEGY FOR ORGANIZING STRENGTH AND CONDITIONING PROGRAMS. THE SELECTED STRATEGY, HOWEVER, SHOULD BE BASED ON THE LEVEL OF THE ATHLETE AND THE CONSTRAINTS OF THE COMPETITIVE SEASON. A COMMON THEME THROUGHOUT ALL THE PERIODIZATION PROTOCOLS IS THE NEED TO MANIPULATE VOLUME LOADS, PROGRESS FROM GENERAL TO SPORT-SPECIFIC TRAINING, AND DISSIPATE FATIGUE. SIGNIFICANT TO THE LATTER, THE USE OF PRECOMPETITION TAPERS APPEARS EVIDENTLY BENEFICIAL. ALTHOUGH ENOUGH ANECDOTAL EVIDENCE EXISTS TO VALIDATE THE USE OF PERIODIZATION, FURTHER SCIENTIFIC INVESTIGATION IS REQUIRED TO UNDERSTAND ITS USE AND LIMITATIONS TO ELITE LEVEL ATHLETES ACROSS EXTENDED PERIODS (E.G., >4 YEARS). UNTIL SUCH TIME, HOWEVER, ITS USE IS RECOMMENDED AND ADVOCATED BY THE RESEARCH HEREIN.
THE INTRODUCTION OF NOVEL TRAINING STIMULI PLAYS A CRUCIAL ROLE IN INDUCING SPECIFIC TRAINING ADAPTATIONS. ONE METHOD THAT CAN BE EMPLOYED TO INTRODUCE A NOVEL STIMULUS TO THE TRAINING PROGRAM WHILE MAXIMIZING THE VELOCITY AND POWER OUTPUT OF THE TRAINING EXERCISE IS THE INCLUSION OF THE CLUSTER SET CONFIGURATION. THE CURRENT REVIEW PRESENTS THE THEORETICAL AND RESEARCH FOUNDATION FOR THE USE OF THE CLUSTER SET IN PERIODIZED TRAINING PROGRAMS AND OFFERS EXAMPLES OF PRACTICAL APPLICATIONS THAT CAN BE USED IN THE PREPARATION OF ATHLETES IN A VARIETY OF SPORTS.
The purpose of this study was to compare serum growth hormone (GH), testosterone (T), cortisol (C), and whole blood lactate (L) responses to single set (1S) versus multiple set (3S) heavy-resistance exercise protocols. Eight recreationally weight-trained men completed two identical resistance exercise workouts (1S vs. 3S). Blood was obtained preexercise (PRE), immediately postexercise (OP), and 5 min (5P), 15 min (15P), 30 min (30P) and 60 min (60P) postexercise and was analyzed for GH, T, C, and L levels. For 1S and 3S, GH, L, and T significantly increased from PRE to OP and remained significantly elevated to 60P, except for 1S. For GH, T, and L, 3S showed significantly greater increases compared to 1S. For C, 3S and 1S were increased significantly from resting at OP, 5P, and 15P; 3S increased compared to 1S at 5P, 15P and 30P. Higher volumes of total work produce significantly greater increases in circulating anabolic hormones during the recovery phase following exercise.
The purpose of this study was to ascertain whether cluster training led to improved power training adaptations in the preseason preparation of elite level rugby union players. Eighteen highly trained athletes were divided into 2 training groups, a traditional training (TT, N = 9) group and a cluster training (CT, N = 9) group before undertaking 8 weeks of lower body resistance training. Force-velocity-power profiling in the jump squat movement was undertaken, and maximum strength was assessed in the back squat before and after the training intervention. Two-way analysis of variance and magnitude-based inferences were used to assess changes in maximum strength and force, velocity, and power values pretraining to posttraining. Both TT and CT groups significantly (p < 0.05) increased maximum strength posttraining. There was a possibly negative effect for the CT group on maximum strength when compared with that for the TT group (pretraining to posttraining change = 14.6 ± 18.0 and 18.3 ± 10.1%, respectively). There were no significant differences pretraining to posttraining for any jump squat force, velocity, or power measures. However, magnitude-based inferences showed that there was a likely positive effect of CT when compared with that of TT for peak power (pretraining to posttraining change = 7.5 ± 7.0 and 1.0 ± 6.2%, respectively) and peak velocity at 40 kg (pretraining to posttraining change = 4.7 ± 6.1 and 0.0 ± 5.0%, respectively) and for peak velocity at body weight (pretraining to posttraining change = 3.8 ± 3.4 and 0.5 ± 3.8%, respectively). Although both a traditional and cluster training loading pattern improved lower body maximum strength in a highly trained population, the traditional training structure resulted in greater maximum strength adaptation. There was some evidence to support the possible benefit of cluster type loading in training prescription for lower body power development.
The relationship between changes in muscle metabolites and the contraction capacity was investigated in humans. Subjects (n = 13) contracted (knee extension) at a target force of 66% of the maximal voluntary contraction force (MVC) to fatigue, and the recovery in MVC and endurance (time to fatigue) were measured. Force recovered rapidly [half-time (t 1/2) less than 15 s] and after 2 min of recovery was not significantly different (P greater than 0.05) from the precontraction value. Endurance recovered more slowly (t 1/2 approximately 1.2 min) and was still significantly depressed after 2 and 4 min of recovery (P less than 0.05). In separate experiments (n = 10) muscle biopsy specimens were taken from the quadriceps femoris muscle before and after two successive contractions to fatigue at 66% of MVC with a recovery period of 2 or 4 min in between. The muscle content of high-energy phosphates and lactate was similar at fatigue after both contractions, whereas glucose 6-phosphate was lower after the second contraction (P less than 0.05). During recovery, muscle lactate decreased and was 74 and 43% of the value at fatigue after an elapsed period of 2 and 4 min, respectively. The decline in H+ due to lactate disappearance is balanced, however, by a release of H+ due to resynthesis of phosphocreatine, and after 2 min of recovery calculated muscle pH was found to remain at a low level similar to that at fatigue.(ABSTRACT TRUNCATED AT 250 WORDS)