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Does Training to Failure Maximize Muscle Hypertrophy?
Abstract
It has been proposed that training to failure is a necessary strategy to maximize muscle growth. This paper examines the research behind these claims, and attempts to draw evidence-based conclusions as to the practical implications for hypertrophy training.
... In summary, the character of the effort is the parameter that marks whether a series is effective for hypertrophy or not, in general, it is considered that a series of high effort character, which is performed with an RIR 4 or lower, can be quantified as a training series [72]. The degree of effort required in each series will influence the tolerable training volume and the perceived exertion of the training [73]. ...
... In the series with low loads is, if possible, even more important, the proximity to muscle failure, as it is the only way to try to match the mechanical stress that occurs in series with higher loads [80]. For its part, the series of high loads, especially if they occur in multi-joint or global exercises, do not require reaching muscle failure if not only to RIR 3-4 [72]. ...
The present chapter delves into the topic of muscle hypertrophy in detail, focusing on defining what muscle hypertrophy is, the types of hypertrophy, the mechanisms, and the relationship with resistance training, as well as the variables affecting hypertrophy such as nutrition, rest, exercise selection, training volume, and training frequency, among others. The importance of mechanical tension, metabolic stress, and muscle damage as triggers for muscle hypertrophy is emphasized. Various types of muscle hypertrophy are explored, including connective tissue hypertrophy and sarcoplasmic and myofibrillar hypertrophy. The text also delves into how hypertrophy mechanisms relate to resistance training, highlighting the significance of mechanical tension and metabolic stress as stimuli for muscle hypertrophy. In a practical point of view, the text also discusses factors like nutrition and recovery, highlighting the importance of maintaining a positive energy balance and adequate protein intake to promote muscle growth optimally. Training variables such as exercise selection, exercise order, intensity, volume, frequency, and tempo of execution are discussed in detail, outlining their impact on muscle hypertrophy. The text provides a comprehensive overview of muscle hypertrophy, analyzing various factors that influence the ability to increase muscle mass. It offers detailed information on the biological mechanisms, types of hypertrophy, training strategies, and nutritional and recovery considerations necessary to achieve optimal results in terms of muscle hypertrophy.
... For instance, training with high loads and lower repetitions is well known to be more specific in improving maximal strength [2], commonly tested in the squat by maximal external load lifted for one repetition maximum (1-RM), due to external load lifted being a result of the maximal force the athlete is able to exert [3]. However, adaptive responses to muscle strength and hypertrophy after a training period are shown to occur at a spectrum of per-set number of repetitions, whereby momentary muscular failure might not be necessitated for improving muscle and strength outcomes [2,4,5]. ...
... . In each RM attempt, a significant decrease in average velocity over the repetitions was found (F�57.5, p<0.001, η p �0.71), while neither significant effects between sexes (F�1.4, ...
Barbell squats are commonly utilized in resistance training for rehabilitation, daily living enhancement, and improving sports performance. The current study investigated the kinematic and electromyographic (EMG) parameters in the squat between sexes across different repetition ranges (1-, 3-, 6-, and 10-RM) among recreationally strength-trained subjects. A total of 26 subjects (13 men: age 25 ± 3.5 years, height 178.2 ± 5.8 cm, weight 82.3 ± 9.1 kg; 13 women: age 24 ± 4.1 years, height 165.4 ± 6.3 cm, weight 68.2 ± 8.7 kg) participated in the study. The level of significance was set at p<0.05. The findings revealed no sex-specific differences in average barbell velocity across repetition ranges. However, the 1-RM showed a significantly lower average velocity compared to the final repetition of other repetition ranges (p<0.001), with the last repetition at 10-RM revealing a significantly higher velocity (p<0.001). Women had greater maximal angular hip extension velocity in the final repetitions of the 6- and 10-RM (p≤0.035, ηp²≤0.20), while both sexes displayed lower maximal angular knee extension velocity in the final repetition of the 10-RM (p = 0.028, ηp² = 0.15). Moreover, men had lower EMG amplitude in the rectus femoris (3- and 10-RM), soleus, and lateral vastus (10-RM) compared to women (p≥0.011, ηp²≥0.26). It was concluded that 10-RM differed greatly in kinematics and EMG, suggesting different fatigue mechanisms compared to other repetition ranges with heavier loads. Furthermore, sex differences in EMG and angular hip extension velocity might imply sex-specific fatiguing mechanisms during high-repetition squats. These considerations could be important when prescribing training programs.
... Moreover, whether the additional metabolic stress generated by muscle failure in each set leads to greater muscle gain is still being determined. There may be a threshold for metabolic stress above which no further beneficial effects are observed (Schoenfeld and Grgic, 2019). In contrast to our results, Karsten et al. (2021) found that the TS group (repetition-to-failure per set) had superior hypertrophic outcomes compared to the RR group (not-to-failure per set). ...
... However, recent studies have not supported that reaching muscle failure in RT provides additional benefits for strength gains (Grgic et al., 2022). In fact, frequent muscle failure can lead to overtraining and overreaching (Fry and Kraemer, 1997;Schoenfeld and Grgic, 2019), which are detrimental to strength development. Surprisingly, our findings are inconsistent with Oliver et al. (2013) despite using a similar set structure and loading in our RT program design. ...
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.
... re results in greater increases in muscular strength or hypertrophy (Caroll et al., 2019;Lasevicius et al., 2019). Other studies suggest that both training strategies can produce similar improvement (Nóbrega et al., 2018;Grgic et al., 2022) or that training to failure has a detrimental effect (Caroll et al., 2018;Caroll et al., 2019). Furthermore, Schoenfeld and Grgic. (2019) hypothesized that training for muscle failure is more important as workloads decrease, due to the delayed recruitment of larger motor units. Lasevicius et al. used 30% and 80% 1RM loads to compare the effect of training to muscle failure vs. non-failure and verified that training to failure promoted greater increases in muscle size in i ...
The study aimed to identify and explain the typical differences in low-intensity high-volume resistance training (LIHV-RT) performances for major muscle groups between rural versus urban young female students to establish the relevant set of quantitative and qualitative resistance training parameters. The study sample included 46 recreational active female students at the Transilvania University of Brașov, (mean ± SD age, 20 ± 1 year; body mass, 60 ± 3 kg; height, 160 ± 4 cm) grouped urban vs. rural. The study used modified resistance exercise machines for the hamstring- and quadricep-group muscles, equipped with a dynamometer and sensors for identifying developed forces and accelerations. A number of 368 tests were performed, representing two attempts for each subject, for knee flexion and knee extension exercises, with two different loads. For the performance analysis some variables were considered: the maximum number of repetition until failure, maximum force developed, maximum acceleration, the duration of the set and the mean time per repetition. The maximum number of repetition to failure shows a significant higher value for rural than urban in case of knee flexion (d = 0.98 [0.32, 1.54] for load 1(L1) and d = 0.65 [0.03, 1.21] for load 2(L2)) and in case of knee extension (d = 1.89 [1.11, 2.48] for L1 and d = 1.67 [0.92, 2.25] for L2). The total duration of the sets shows a significant higher value for rural than urban in case of knee flexion (d = 0.84 [0.19, 1.39] for L2) and in case of knee extension (d = 1.46 [0.74, 2.03] for L1 and d = 1.56 [0.98, 2.14] for L2). Additionally we found differences in the quality of the relevant repetitions execution and in the impulse developed during the LIHV- MNRF sets. The study’s main finding was that there are differences in LIHV-RT performances knee flexion and knee extension antagonistic exercises, between rural and urban female students. We concluded that the obtained results allow teachers to understand the optimal design of RT programs for the different groups of participants, in order to adapt their teaching techniques so that their final objectives are achieved, insisting on particular aspects of the theoretical or practical contents.
... The prescription of a training program focused on enhancing strength and muscle hypertrophy requires careful consideration of various factors, including biological individuality, contractions mode, specificity, and the physiological effects (1,2). Recently, there has been extensive debate on whether training to failure is more effective than training without reaching failure in terms of muscle hypertrophy (3)(4)(5)(6). The results highlighted that both strategies of training could offer a similar stimulus to induce muscle grown (7). ...
Background. Previous studies suggest training to failure may not yield superior muscle responses compared to non-failure training, leaving the combined use unexplored.
Objective. To compare the number of repetitions, volume-load, time under tension (TUT), rate of perceived exertion (RPE), and muscle swelling between two protocols: one involving four sets to failure (TFAS) and the other involving only the final set reaching failure (TFLS).
Methods. Fourteen trained adults completed both conditions in four sessions, with the first two sessions dedicated to determining the one-repetition maximum (1RM) for the barbell preacher curl exercise. In the third session, participants completed TFAS, maxing repetitions across four sets at 70% of 1RM. In the fourth session (TFLS), they fixed repetition in the first three sets (mean achieved during TFAS), with the final set to failure. In both sessions, repetitions, volume-load, RPE, and TUT were recorded postset. Before and immediately after both TFAS and TFLS, participants’ biceps brachii cross-sectional area at 50% of humerus length was measured using ultrasound imaging to assess muscle swelling. Comparisons used ANOVA and paired t tests.
Results. TFAS had higher RPE across sets (TFLS = 32 ± 4; TFAL = 37 ± 4) and a greater total TUT compared to TFLS (TFLS = 168 ± 44 s; TFAL = 178 ± 41 s). TFLS achieved more repetitions (TFLS = 38.93 ± 6.51; TFAL = 37.36 ± 5.24) and volumeload (TFLS = 918.55 ± 235.38 kg; TFAL = 888.77 ± 241.46 kg). Both protocols showed similar muscle swelling (TFLS = 23.90 ± 5.27 cm2; TFAL = 20.73 ± 10.71 m2).
Conclusions. TFLS allowed for more repetitions with lower RPE, with no difference in swelling.
KEY WORDS: Failure; non-failure; muscle swelling; repetitions; rate of perceived exertion; repetitions
... (CMJ) data can indirectly evaluate the level of the explosive power of athletes' lower limbs. 4 Therefore, the vertical jump tester was used to test the subjects' squat and jump (CMJ) movements before and after the strength training. Each person will take 3 tests and record the best results after 20s intervals. ...
Introduction
Specific training with vibration can show short- and long-term effects on neuromuscular capacity. This training method gives muscles a frequent stimulus amplitude variation and can promote muscle strength, explosive power, neuromuscular coordination, and balance training.
Objective
This paper compares the effects of strength training with vibration on the strength of small muscle groups in the lower limbs of athletes.
Methods
24 young people were randomly assigned to a low- and high-frequency group. Both groups used traditional strength training with the addition of 30 and 40Hz vibrational training. Training with load intensity between 30 and 70% of maximal strength lasting 60 minutes was repeated in 3 weekly sessions for eight weeks. Functional tests were recorded before and after the experiment, and their results were statistically analyzed.
Results
The peak torque of the hip muscles of the two groups of athletes increased significantly after training (P<0.05). In the high-frequency athletes, the peak in the hip extensor increased by 15.3% and the flexor by 18.2%; in the low-frequency group, there was an increase of 10.3%, representing a very significant difference (P<0.01).
Conclusion
Additional vibration stimulation for resistance strength training can effectively improve strength training. With a relatively small load, this training method can effectively improve maximal muscular strength, explosive power, and muscular endurance. Evidence level II; Therapeutic Studies - Investigating the results.
Resistance Training; Athletes; Lower Limbs; Neuromuscular Diseases
... Nonetheless, it is hypothesised that RT should be performed with a closer proximity-to-failure when lower loads are lifted versus higher loads. This strategy would theoretically maximise muscle fibre activation and subsequent muscle hypertrophy [36], and although the ES differences may provide support for this hypothesis, more research comparing lower load and higher load RT is required to elucidate the influence of relative load on muscle hypertrophy when RT is performed to different proximities-to-failure. Although we found no moderating effect of relative load on the overall ES for muscle hypertrophy (p = 0.525), future research should continue exploring the interaction of RT variables (e.g. ...
Background and Objective: This systematic review with meta-analysis investigated the influence of resistance training proximity-to-failure on muscle hypertrophy.
Methods: Literature searches in the PubMed, SCOPUS and SPORTDiscus databases identified a total of 15 studies that measured muscle hypertrophy (in healthy adults of any age and resistance training experience) and compared resistance training performed to: (A) momentary muscular failure versus non-failure; (B) set failure (defined as anything other than momentary muscular failure) versus non-failure; or (C) different velocity loss thresholds.
Results: There was a trivial advantage for resistance training performed to set failure versus non-failure for muscle hypertrophy in studies applying any definition of set failure [effect size=0.19 (95% confidence interval 0.00, 0.37), p=0.045], with no moderating effect of volume load (p=0.884) or relative load (p=0.525). Given the variability in set failure definitions applied across studies, sub-group analyses were conducted and found no advantage for either resistance training performed to momentary muscular failure versus non-failure for muscle hypertrophy [effect size=0.12 (95% confidence interval −0.13, 0.37), p=0.343], or for resistance training performed to high (>25%) versus moderate (20–25%) velocity loss thresholds [effect size=0.08 (95% confidence interval −0.16, 0.32), p=0.529].
Conclusion: Overall, our main findings suggest that (i) there is no evidence to support that resistance training performed to momentary muscular failure is superior to non-failure resistance training for muscle hypertrophy and (ii) higher velocity loss thresholds, and theoretically closer proximities-to-failure do not always elicit greater muscle hypertrophy. As such, these results provide evidence for a potential non-linear relationship between proximity-to-failure and muscle hypertrophy.
... However, there is evidence to suggest that performing repetitions at or close to concentric muscular failure may not be necessary to develop these physical qualities, rather ceasing a set multiple repetitions short of concentric muscular failure may be adequate (10,16). However, the findings from these studies are highly variable (27,38), as observed in recent reviews concerning muscular strength and hypertrophy (5,48) and indicate that the current consensus is inconclusive with more research needed to build on current recommendations (42). ...
Davies, TB, Halaki, M, Orr, R, Mitchell, L, Helms, ER, Clarke, J, and Hackett, DA. Effect of set structure on upper-body muscular hypertrophy and performance in recreationally trained men and women. J Strength Cond Res 36(8): 2176–2185, 2022—This study explored the effect of volume-equated traditional-set and cluster-set structures on muscular hypertrophy and performance after high-load resistance training manipulating the bench press exercise. Twenty-one recreationally trained subjects (12 men and 9 women) performed a 3-week familiarization phase and were then randomized into one of two 8-week upper-body and lower-body split programs occurring over 3 and then progressing to 4 sessions per week. Subjects performed 4 sets of 5 repetitions at 85% one repetition maximum (1RM) using a traditional-set structure (TRAD, n = 10), which involved 5 minutes of interset rest only, or a cluster-set structure, which included 30-second inter-repetition rest and 3 minutes of interset rest (CLUS, n = 11). A 1RM bench press, repetitions to failure at 70% 1RM, regional muscle thickness, and dual-energy x-ray absorptiometry were used to estimate changes in muscular strength, local muscular endurance, regional muscular hypertrophy, and body composition, respectively. Velocity loss was assessed using a linear position transducer at the intervention midpoint. TRAD demonstrated a significantly greater velocity loss magnitude (g = 1.50) and muscle thickness of the proximal pectoralis major (g = −0.34) compared with CLUS. There were no significant differences between groups for the remaining outcomes, although a small effect size favoring TRAD was observed for the middle region of the pectoralis major (g = −0.25). It seems that the greater velocity losses during sets observed in traditional-set compared with cluster-set structures may promote superior muscular hypertrophy within specific regions of the pectoralis major in recreationally trained subjects.
Objetivo:
El objetivo de la presente revisión sistemática fue determinar los efectos del entrenamiento cluster sobre la hipertrofia muscular.
Metodología:
Se realizó una búsqueda bibliográfica en las bases de datos electrónicas Pubmed, Scopus y Web of Science, utilizando las siguientes palabras clave: 'cluster training', 'rest Interval', 'rest pause', 'hypertrophy', 'resistance training' y 'cross sectional area'. Se incluyeron ensayos clínicos que utilizaron el entrenamiento cluster como intervención en personas mayores de 18 años de ambos sexos.
Resultados:
La revisión sistemática obtenida durante la búsqueda de las bases de datos consultadas arrojó un total de 23 artículos, potencialmente elegibles, de los cuales se tomó una muestra de 9, con los que se podían obtener resultados que respondían al objetivo de esta revisión. La cantidad de participantes de los 9 artículos elegibles fue de 172 sujetos. Los entrenamientos cluster permiten aumentar el volumen de entrenamiento y la intensidad sin provocar elevados niveles de fatiga, favoreciendo así el desarrollo de la hipertrofia muscular.
Conclusiones:
Los resultados de esta revisión sistemática sugieren que los entrenamientos cluster pueden ser una herramienta eficaz para el desarrollo de la hipertrofia muscular.
Training frequency is considered an important variable in the hypertrophic response to regimented resistance exercise. The purpose of this paper was to conduct a systematic review and meta-analysis of experimental studies designed to investigate the effects of weekly training frequency on hypertrophic adaptations. Following a systematic search of PubMed/MEDLINE, Scoups, and SPORTDiscus databases, a total of 25 studies were deemed to meet inclusion criteria. Results showed no significant difference between higher and lower frequency on a volume-equated basis. Moreover, no significant differences were seen between frequencies of training across all categories when taking into account direct measures of growth, in those considered resistance-trained, and when segmenting into training for the upper body and lower body. Meta-regression analysis of non-volume-equated studies showed a significant effect favoring higher frequencies, although the overall difference in magnitude of effect between frequencies of 1 and 3+ days per week was modest. In conclusion, there is strong evidence that resistance training frequency does not significantly or meaningfully impact muscle hypertrophy when volume is equated. Thus, for a given training volume, individuals can choose a weekly frequency per muscle groups based on personal preference.
One of the most striking adaptations to exercise is the skeletal muscle hypertrophy that occurs in response to resistance exercise. A large body of work shows that a mTORC1-mediated increase of muscle protein synthesis is the key, but not sole, mechanism by which resistance exercise causes muscle hypertrophy. Whilst much of the hypertrophy signaling cascade has been identified, the initiating, resistance exercise-induced and hypertrophy-stimulating stimuli have remained elusive. For the purpose of this review, we define an initiating, resistance exercise-induced and hypertrophy-stimulating signal as "hypertrophy stimulus", and the sensor of such a signal as "hypertrophy sensor". In this review we discuss our current knowledge of specific mechanical stimuli, damage/injury-associated and metabolic stress-associated triggers as potential hypertrophy stimuli. Mechanical signals are the prime hypertrophy stimuli candidates and a Filamin-C-BAG3-dependent regulation of mTORC1, Hippo and autophagy signalling is a plausible albeit still incompletely characterised hypertrophy sensor. Other candidate mechanosensing mechanisms are nuclear deformation-initiated signalling or several mechanisms related to costameres, which are the functional equivalents of focal adhesions in other cells. Whilst exercise-induced muscle damage is probably not essential for hypertrophy, it is still unclear whether and how such muscle damage could augment a hypertrophic response. Interventions that combine blood flow restriction and especially low load resistance exercise suggest that resistance exercise-regulated metabolites could be hypertrophy stimuli but this is based on indirect evidence and metabolite candidates are poorly characterised.
Repetitions in Reserve' (RIR) scales in resistance training (RT) are used to control effort but assume people accurately predict performance a priori (i.e. the number of possible repetitions to momentary failure (MF)). This study examined the ability of trainees with different experience levels to predict number of repetitions to MF. One hundred and forty-one participants underwent a full body RT session involving single sets to MF and were asked to predict the number of repetitions they could complete before reaching MF on each exercise. Participants underpredicted the number of repetitions they could perform to MF (Standard error of measurements [95% confidence intervals] for combined sample ranged between 2.64 [2.36-2.99] and 3.38 [3.02-3.83]). There was a tendency towards improved accuracy with greater experience. Ability to predict repetitions to MF is not perfectly accurate among most trainees though may improve with experience. Thus, RIR should be used cautiously in prescription of RT. Trainers and trainees should be aware of this as it may have implications for the attainment of training goals, particularly muscular hypertrophy. Subjects Anatomy and Physiology, Kinesiology
Purpose:
To describe the acute and delayed time course of recovery following resistance training (RT) protocols differing in the number of repetitions (R) performed in each set (S) out of the maximum possible number (P).
Methods:
Ten resistance-trained men undertook three RT protocols [S × R(P)]: (1) 3 × 5(10), (2) 6 × 5(10), and (3) 3 × 10(10) in the bench press (BP) and full squat (SQ) exercises. Selected mechanical and biochemical variables were assessed at seven time points (from - 12 h to + 72 h post-exercise). Countermovement jump height (CMJ) and movement velocity against the load that elicited a 1 m s(-1) mean propulsive velocity (V1) and 75% 1RM in the BP and SQ were used as mechanical indicators of neuromuscular performance.
Results:
Training to muscle failure in each set [3 × 10(10)], even when compared to completing the same total exercise volume [6 × 5(10)], resulted in a significantly higher acute decline of CMJ and velocity against the V1 and 75% 1RM loads in both BP and SQ. In contrast, recovery from the 3 × 5(10) and 6 × 5(10) protocols was significantly faster between 24 and 48 h post-exercise compared to 3 × 10(10). Markers of acute (ammonia, growth hormone) and delayed (creatine kinase) fatigue showed a markedly different course of recovery between protocols, suggesting that training to failure slows down recovery up to 24-48 h post-exercise.
Conclusions:
RT leading to failure considerably increases the time needed for the recovery of neuromuscular function and metabolic and hormonal homeostasis. Avoiding failure would allow athletes to be in a better neuromuscular condition to undertake a new training session or competition in a shorter period of time.
The history of resistance training research began with anecdotal ideas and a slow growth of research from the late 1890s through the 1970s. The mid-1970s were a nexus point when resistance training studies evolved from just strength assessments to importance in physiological systems, physical health, and physical performance capabilities for individuals interested in physical fitness through to those seeking elite athletic performances. The pursuit of understanding program design and what mediated successful programs continues today as new findings, replication of old concepts, and new visions with the latest technologies fuel both our understanding and interest in this modality. This brief review highlights some of the important scientific contributions to the evolution of our scientific study of resistance training and provides a literature base analysis for greater quantification of the origins and expanse of such investigations.
The purpose of this paper was to conduct a systematic review of the current body of literature and a meta-analysis to compare changes in strength and hypertrophy between low- versus high-load resistance training protocols. Searches of PubMed/MEDLINE, Cochrane Library and Scopus were conducted for studies that met the following criteria: 1) an experimental trial involving both low- (≤60% 1 RM) and high- (>60% 1 RM) load training; 2) with all sets in the training protocols being performed to momentary muscular failure; 3) at least one method of estimating changes in muscle mass and/or dynamic, isometric or isokinetic strength was used; 4) the training protocol lasted for a minimum of 6 weeks; 5) the study involved participants with no known medical conditions or injuries impairing training capacity. A total of 21 studies were ultimately included for analysis. Gains in 1RM strength were significantly greater in favor of high- versus low-load training, while no significant differences were found for isometric strength between conditions. Changes in measures of muscle hypertrophy were similar between conditions. The findings indicate that maximal strength benefits are obtained from the use of heavy loads while muscle hypertrophy can be equally achieved across a spectrum of loading ranges.
Abstract Santos, WDNd, Vieira, CA, Bottaro, M, Nunes, VA, Ramirez-Campillo, R, Steele, J, Fisher, JP, and Gentil, P. Resistance training performed to failure or not to failure results in similar total volume, but with different fatigue and discomfort levels. J Strength Cond Res XX(X): 000–000, 2018—The purpose of this study was to compare the acute response to 4 sets of high velocity of parallel squats performed to momentary failure (MF) or not to momentary failure (NF). Twelve women (24.93 ± 5.04 years) performed MF and NF protocols, in a randomized order with 2–3 interday rest. The protocol involved 4 sets of parallel squats executed at high velocity at 10RM load, with 2 minutes of rest interval between sets. During the NF protocol, the sets were interrupted when the participant lost more than 20% of mean propulsive velocity. The analysis involved the number of repetitions performed per set, total number of repetitions, movement velocity loss, power output loss, rating of perceived exertion (RPE), rating of perceived discomfort (RPD), and session rating of perceived exertion (sRPE). Compared with NF, MF resulted in a higher number of repetitions in the first set (11.58 ± 1.83 vs. 7.58 ± 1.72, p < 0.05), but a lower in the last set (3.58 ± 1.08 vs. 5.41 ± 1.08, p < 0.05). Total number of repetitions was similar between the protocols (MF 26.25 ± 3.47 vs. NF 24.5 ± 3.65, p > 0.05). In both protocols, there were significant decreases in maximum and mean movement velocity loss and power output loss, but higher decreases were observed in MF than NF (p < 0.05). Values for RPE, sRPE, and RPD were higher during MF than NF (p < 0.05). Controlling the movement velocity in NF protocol enabled performance of a similar total volume of repetitions with lower movement velocity and power output losses, RPE, sRPE, and RPD than during an MF protocol.
Pareja-Blanco, F, Rodríguez-Rosell, D, Aagaard, P, Sánchez-Medina, L, Ribas-Serna, J, Mora-Custodio, R, Otero-Esquina, C, Yáñez-García, JM, and González-Badillo, JJ. Time course of recovery from resistance exercise with different set configurations. J Strength Cond Res XX(X): 000-000, 2018-This study analyzed the response to 10 resistance exercise protocols differing in the number of repetitions performed in each set (R) with respect to the maximum predicted number (P). Ten males performed 10 protocols (R(P): 6(12), 12(12), 5(10), 10(10), 4(8), 8(8), 3(6), 6(6), 2(4), and 4(4)). Three sets with 5-minute interset rests were performed in each protocol in bench press and squat. Mechanical muscle function (countermovement jump height and velocity against a 1 m·s load, V1-load) and biochemical plasma profile (testosterone, cortisol, growth hormone, prolactin, IGF-1, and creatine kinase) were assessed at several time points from 24-hour pre-exercise to 48-hour post-exercise. Protocols to failure, especially those in which the number of repetitions performed was high, resulted in larger reductions in mechanical muscle function, which remained reduced up to 48-hour post-exercise. Protocols to failure also showed greater increments in plasma growth hormone, IGF-1, prolactin, and creatine kinase concentrations. In conclusion, resistance exercise to failure resulted in greater fatigue accumulation and slower rates of neuromuscular recovery, as well as higher hormonal responses and greater muscle damage, especially when the maximal number of repetitions in the set was high.
This study investigated the effects of a 10-week resistance training to failure on neuromuscular adaptations in young women. Eighty-nine active young women were randomly assigned to one of three groups: 1) repetitions to failure (RF; three sets of repetitions to failure); 2) repetitions not to failure with equalized volume (RNFV; four sets of 7 repetitions); and 3) repetitions not to failure (RNF; three sets of 7 repetitions). All groups performed the elbow flexor exercise (bilateral biceps curl) and trained 2 days per week using 70% of 1RM. There were significant increases (p<0.05) in muscle strength after 5 (15.9% for RF, 18.4% for RNF, and 19.9% for RNFV) and 10 (28.3% for RF, 26.8% for RNF, and 28.3% for RNFV) weeks of training, with no significant differences between groups. Additionally, muscular endurance increased after 5 and 10 weeks, with no differences between groups. However, peak torque (PT) increased significantly at 180°.s-1 in the RNFV (13.7%) and RNF (4.1%) groups (p<0.05), whereas no changes were observed in the RF group (-0.5%). Muscle thickness increased significantly (p<0.05) in the RF and RNFV groups after 5 (RF: 8.4% and RNFV: 2.3%) and 10 weeks of training (RF: 17.5%, and RNFV: 8.5%), whereas no significant changes were observed in the RNF group (3.9 and 2.1% after 5 and 10 weeks, respectively). These data suggest that short-term training of repetitions to failure do not yield additional overall neuromuscular improvements in young women.