Effects of Prolonging Eccentric Phase Duration in Parallel Back-Squat Training to Momentary Failure on Muscle Cross-Sectional Area, Squat One Repetition Maximum, and Performance Tests in University Soccer Players

The effects of eccentric phase tempo in squats on hypertrophy, strength, and contractile properties of the quadriceps femoris muscle

Introduction

The aim of the present study was to investigate the effects of eccentric phase tempo in squats on hypertrophy, strength, and contractile properties of the quadriceps femoris (QF) muscle.

Methods

Eighteen participants (10 males and 8 females, age 24.0 ± 1.7 years) with no resistance training (RT) experience in the last 8 months were randomized into two groups, each following a 7 week squat resistance training (RT) protocol with either a fast eccentric (FE, 1 s eccentric/0 s isometric/1 s concentric/0 s isometric) or slow eccentric (SE, 4 s eccentric/0 s isometric/1 s concentric/0 s isometric) tempo. The training intensity (60%-70% RM), the number of sets (3-4), and the rest intervals (120 s) were consistent in both groups. The study measured changes in quadriceps cross-sectional area (CSA), one-repetition maximum (1RM) strength, and muscle contractile properties such as contraction time (Tc) and radial displacement (Dm), using tensiomyography (TMG). An ANCOVA model with baseline values as covariates was used to examine between-group differences.

Results

Results showed significant strength gains in both groups, with the SE group achieving greater 1RM increases (effect size [ES] = 1.60 vs 0.99, p < 0.05). CSA increased for all QF muscles; however, the SE group exhibited significantly higher hypertrophy in the vastus lateralis (ES = 1.74 vs. 1.37, p < 0.05). TMG analysis revealed decreased Dm in the rectus femoris for both groups (p < 0.05), while Tc significantly (ES = 1.33, p < 0.01) increased in the SE group.

Discussion

These findings suggest that slower eccentric tempo in RT may optimize vastus lateralis hypertrophy and enhance strength while promoting muscle fiber-type specificity, contributing to the understanding of eccentric training's role in muscle adaptation.

Stretch-Shortening Cycle Utilization in Female and Male Soccer Players: A Systematic Review

ABSTRACT

Santos, SCR, Oliveira, AR, Costa, RA, Nascimento, KSB, Alvares, PD, Medeiros, FB, Assumpção, CO, Ramos, GP, Banja, T, Veneroso, CE, Claudino, JGO, and Cabido, CET. Stretch-shortening cycle utilization in female and male soccer players: A systematic review. J Strength Cond Res 38(10): e600-e625, 2024-The stretch-shortening cycle (SSC) enhances strength and power in soccer players. However, little consistent information is found on expected SSC utilization in soccer players. The aim of the present study was to provide information on SSC utilization in soccer players of different sexes, ages, and competitive levels through the calculation of the percent of prestretch augmentation (PPA ((CMJ - SJ)/SJ × 100)). A systematic review was performed of studies involving soccer players. After screening 3,921 studies, 214 assessing a total of 11,941 players were considered eligible. Twenty studies involved females (747 subjects), 16 of which involved professionals (380 players), and 7 of which involved nonprofessionals (367 players). One hundred ninety-seven studies involved males (11,194 subjects), 56 of which involved professionals (2,508 players), 16 involved semiprofessionals (698 players), and 135 involved young athletes [67 involved postpubertal youths (2,439 players) and 85 involved youths (5,549 players)]. Prestretch augmentation was 9.35% (95% CI: 6.33-12.38%) for professional and 5.73% (95% CI: 3.06-8.40%) for nonprofessional female players. For males, PPA was 6.16% (95% CI: 5.03-7.29%) for professional players, 8.55% (95% CI: 5.76-11.33%) for semiprofessionals, 6.64% (95% CI: 5.76-7.53%) for postpubertal youths, and 7.00% (95% CI: 6.11-7.90%) for youths. Stretch-shortening cycle utilization measured based on PPA in the sample studied ranged from 3.06 to 12.38%. These values could serve as reference to indicate the appropriate use of SSC among soccer players according to competitive level and sex, which could help coaches and physical trainers develop appropriate training programs.

Can resistance training improve throwing performance in handball players? A Systematic review and meta-analysis

BACKGROUND

Throwing is one of the most important movement in handball. Throwing performance is crucial for success in handball.

OBJECTIVE

Τo investigate the level of evidence for the effect of resistance training (RT) on throwing performance in handball players.

METHODS

Systematic searches of Pubmed, Medline complete, Cinahl, Sport Discus and Scopus were undertaken for peer reviewed articles published between 18 March 1995 to 18 March 2023. Randomized, controlled, clinical studies, written in English, aiming to investigate the effect at least one modality of RT on throwing performance (velocity or/and accuracy) in handball players were considered for inclusion in the study. The eligible studies were assessed for methodological quality using the Physical Therapy Evidence Database (PEDRO) scale. The Best Evidence Synthesis (BES) approach was used for synthesizing and reporting the results. Furthermore, the random-effects model was used for the meta-analysis and the Q-statistic was used to test the null hypothesis that all studies in the analysis share a common effect size.

RESULTS

One hundred ninety-eight studies were identified, of which 30 were included. A total of 727 handball players (males = 388, females = 292) were included. 28 of the 30 studies were rated as high methodological quality studies (PEDRO score > 70%) while the rest of the studies were rated as moderate methodological quality studies (PEDRO score ≤ 60%). The mean effect size for the effectiveness of resistance training (RT) in improving jumping throw, running throw, and standing throw velocity were 1.128 (95% CI 0.457 - 1.798), 1.756 (95% CI 1.111 - 2.400), and 1.098 (95% CI 0.689 - 1.507) correspondingly. Traditional weight training using barbells in mostly compound lifts yielded the most significant and robust results. Other RT modalities such as elastic bands, medicine balls, core training and ballistic training showed no significant results or positive effects due to the limited number of the studies.

CONCLUSION

Strong evidence exists only for the effectiveness of RT using barbells in increasing throwing velocity. In contrast, the remaining RT modalities, while yielding positive results, have limited support due to limited number of studies and the high heterogeneity between studies. Furthermore, there is insufficient evidence to support various forms of RT in increasing throw distance. Finally, medicine ball training and elastic band training demonstrated no benefits in improving throwing accuracy.

TRIAL REGISTRATION

PROSPERO ID: CRD42023393574.

Optimizing Resistance Training Technique to Maximize Muscle Hypertrophy: A Narrative Review

Regimented resistance training (RT) has been shown to promote increases in muscle size. When engaging in RT, practitioners often emphasize the importance of appropriate exercise technique, especially when trying to maximize training adaptations (e.g., hypertrophy). This narrative review aims to synthesize existing evidence on what constitutes proper RT exercise technique for maximizing muscle hypertrophy, focusing on variables such as exercise-specific kinematics, contraction type, repetition tempo, and range of motion (ROM). We recommend that when trying to maximize hypertrophy, one should employ a ROM that emphasizes training at long muscle lengths while also employing a repetition tempo between 2 and 8 s. More research is needed to determine whether manipulating the duration of either the eccentric or concentric phase further enhances hypertrophy. Guidelines for body positioning and movement patterns are generally based on implied theory from applied anatomy and biomechanics. However, existing research on the impact of manipulating these aspects of exercise technique and their effect on hypertrophy is limited; it is therefore suggested that universal exercise-specific kinematic guidelines are followed and adopted in accordance with the above recommendations. Future research should investigate the impact of stricter versus more lenient exercise technique variations on hypertrophy.

Intentionally Slow Concentric Velocity Resistance Exercise and Strength Adaptations: A Meta-Analysis

ABSTRACT

Hermes, MJ and Fry, AC. Intentionally slow concentric velocity resistance exercise and strength adaptations: a meta-analysis. J Strength Cond Res 37(8): e470-e484, 2023-Intentionally slow-velocity resistance exercise (ISVRE) is suggested by some to be equally or more effective than fast or traditional velocities for increasing muscular strength. The purpose of this meta-analysis was to assess the effect ISVRE has on strength adaptations compared with faster or traditional velocities, with subgroup analyses exploring age, sex, and training status as confounding factors on the influence of velocity on strength adaptation. Eligible studies (n = 24) were required to be chronic (multiple weeks) randomized or nonrandomized comparative studies using dynamic constant external resistance for training and testing, and pre-post strength assessments. All studies examined healthy individuals (n = 625; fast or traditional n = 306, intentionally slow n = 319). A random-effects meta-analysis indicated a significant (p ≤ 0.05) effect in favor of fast training (effect size [ES] = 0.21, 95% confidence interval [CI] = 0.02-0.41, p = 0.03). Publication bias was noted through trim and fill analysis, with an adjusted effect size estimate of 0.32 (p < 0.001). Subgroup analyses indicated no difference between trained and untrained subjects (QM = 0.01, p = 0.93), and no difference between older and younger subgroups (QM = 0.09, p = 0.77), despite younger favoring faster (ES = 0.23, p = 0.049) and older not favoring either velocity (ES = 0.16, p = 0.46). Subgroup analysis also indicated women favored faster training (ES = 0.95, p < 0.001) in comparison to men (ES = 0.08, p = 0.58). Contrary to some previous reviews, these results indicate that chronic fast or traditional velocity resistance exercise increases muscular strength to a greater degree than ISVRE training. Resistance training velocity must be considered if strength is a desired outcome.

Fast and Medium Tempo Resistance Training with a Low Number of Repetitions in Trained Men: Effects on Maximal Strength and Power Output

This study aimed to investigate the effects of high load fast and medium tempo back squats using a low number of repetitions on maximal strength and power output. Seventeen participants completed a countermovement jump test and 1-repetition maximum (1-RM) assessment before and after an eight-week intervention. All participants were randomly divided into a fast tempo (FAS: 1/0/1/0) and a medium tempo (MED: 2/0/2/0) resistance training (RT) group and performed three repetitions per set of a Smith back squat exercise with 85% 1-RM intensity. Maximal strength, jump height, peak power and force of the two groups were significantly improved (p < 0.05). In addition, peak velocity significantly increased after the intervention in the FAS group (p < 0.05), but not in the MED group (p > 0.05). A significant interaction effect between training groups was observed for jump height (F (_{1, 30}) = 5.49, p = 0.026, η² = 0.155). However, no significant group by time interaction effects were found between training groups for maximal strength (F (_{1, 30}) = 0.11, p = 0.742, η² = 0.004). Therefore, the two groups showed similar effects in maximal strength, but, compared with the MED group, FAS resistance training with low repetitions caused favorable adaptations in power output in trained men.

Hypertrophic adaptations to a 6-week in-season barbell vs. flywheel squat added to regular soccer training

BACKGROUND

The aim of this study was to compare the hypertrophic adaptations to barbell or flywheel squat exercise added to regular in-season soccer training.

METHODS

Quadriceps' (rectus femoris [RF], vastus medialis [VM] and vastus lateralis [VL]) cross-sectional area (CSA) in its portions (proximal [PROX], middle [MID], and distal [DIST]) was measured on both legs before and after a 6-week barbell (80 to 90% one-maximum repetition; N.=7) or flywheel (0.0611 to 0.0811 kg·m²; N.=7) in an U19 professional soccer team using a 3T magnetic resonance imaging. Both groups underwent 5 sets × 6 reps per session of squat separated by 3-min rest, while controlling the time under tension (within 0.5 and 0.8 s).

RESULTS

The barbell squat group experienced moderate CSA increments in the VM<inf>MID</inf> and the VL<inf>DIST</inf> of the right leg (d=0.98-0.99). Additionally, the flywheel group experience large CSA increments in the RF<inf>MID</inf>, VL<inf>PROX</inf> and VL<inf>MID</inf> of the right leg (d=1.00-1.84). On average, flywheel squat training largely produced greater force during exercise compared to the barbell squat training (29.2 vs. 12.2 N·kg^-1; d=5.95), whereas the barbell squat training produced moderately greater power output (10.5 vs. 9.7; d=0.52).

CONCLUSIONS

Barbell squat training seems to be more effective for VM hypertrophy whereas flywheel squat triggers greater RF and VL hypertrophy as complementary to regular field-based soccer practice and competition within a short range of time (6 weeks) during the in-season. These findings can be considered also from either strength or reconditioning perspective based on the increase in the quadriceps muscles' CSA as mechanism underlying strength/power adaptations.

Effects of Strength Training on BDNF in Healthy Young Adults

The physical improvements from strength and resistance training have been known for decades, but the cognitive benefits of this type of activity are not as well-known. The aim of this review article is to provide a summary of studies presenting the effects of strength and resistance training on BDNF in healthy young adults. A systematic search of various electronic databases (PubMed, Web of Science, Science Direct and Google Scholar) was conducted in September 2022. Studies that examined associations between strength training and BDNF in healthy young adults aged 18-30 years were included. The final sample included 10 studies published between 2009 and 2020. The results of this literature review are inconclusive. Based on the results of the 10 studies, there is no clear answer as to whether strength training has positive effects on BDNF in healthy young adults.

Acute effect of resistance exercise at different velocities on stiffness and vascularity of the biceps brachii muscle: a preliminary study

Background

Resistance exercise can be defined as the percentage of maximal strength (%1 repetition maximum) used for a particular exercise. Shear wave elastography (SWE) is a robust and novelty imaging technique that provides information regarding tissue stiffness. Superb microvascular imaging (SMI) is a non-irradiating technique that can provide quantitative measurement of muscle blood flow non-invasively.

Purpose

To compare the acute effects of low- and high-velocity resistance exercise on stiffness and blood flow in the biceps brachii muscle (BBM) using SWE and SMI.

Material and Methods

This prospective study included 60 healthy men (mean age=28.9 years; age range=26–34 years). BBM stiffness was measured by using SWE at rest, after low- and high-velocity resistance exercise, and muscle blood flow was also evaluated by SMI. Resistance exercise was performed using a dumbbell with a mass adjusted to 70%–80% of one-repetition maximum.

Results

The stiffness values increased significantly from resting to high- and low-velocity resistance exercises. There was no significant difference between the elastography values of the BBM after the high- and low-velocity resistance exercise. The blood flow increased significantly from resting to high- and low-velocity resistance exercises. Blood flow increase after low-velocity exercise was significantly higher compared to high-velocity exercise.

Conclusion

While muscle stiffness parameters and blood flow significantly increased from resting after both high- and low-velocity resistance exercises, blood flow significantly increased after low-velocity exercise compared to high-velocity exercise. This can mean that metabolic stress, an important trigger for muscle development, is more likely to occur in low-velocity exercise.

Slow-Speed Compared With Fast-Speed Eccentric Muscle Actions Are Detrimental to Jump Performance in Elite Soccer Players In-Season

PURPOSE

To examine the effect of fast- versus slow-speed eccentric-muscle-action resistance training on lower-body strength, vertical jump height, sprint speed, and change-of-direction performance in elite soccer players during a competitive season.

METHODS

Twenty-two elite soccer players, from a single team, were randomly assigned to groups that undertook either 1- (fast speed) or 4-second (slow speed) eccentric resistance training during the in-season period. A 5-week program was conducted during an elite top-division European League soccer season. Performance measures including predicted 1-repetition-maximum back squat, countermovement jump, 20-m sprint, and change of direction were tested before and after the intervention period. Total match and training running distance and muscle soreness were also recorded during each week of the intervention.

RESULTS

An analysis of covariance showed significant group effects (P = .01) for countermovement jump with a greater jump height in the 1-second fast-speed group postintervention (95% CI, 1.1-6.9 cm). Despite an overall increase in 1-repetition maximum pretraining to posttraining (95% CI, 10.0-15.3 kg, effect size 0.69), there were no significant differences (P > .05) between groups after the intervention. Similarly, there were no differences between groups for change of direction, 20-m sprint, or muscle soreness.

CONCLUSION

Faster eccentric muscle actions may be superior for increasing movements in elite soccer players in-season.

The Need for Eccentric Speed: A Narrative Review of the Effects of Accelerated Eccentric Actions During Resistance-Based Training

Eccentric training as a method to enhance athletic performance is a topic of increasing interest to both practitioners and researchers. However, data regarding the effects of performing the eccentric actions of an exercise at increased velocities are limited. This narrative review aimed to provide greater clarity for eccentric methods and classification with regard to temporal phases of exercises. Between March and April 2021, we used key terms to search the PubMed, SPORTDiscus, and Google Scholar databases within the years 1950-2021. Search terms included 'fast eccentric', 'fast velocity eccentric', 'dynamic eccentric', 'accentuated eccentric loading', and 'isokinetic eccentric', analysing both the acute and the chronic effects of accelerated eccentric training in human participants. Review of the 26 studies that met the inclusion criteria identified that completing eccentric tempos of < 2 s increased subsequent concentric one repetition maximum performance, velocity, and power compared with > 4 s tempos. Tempos of > 4 s duration increased time under tension (TUT), whereas reduced tempos allowed for greater volume to be completed. Greater TUT led to larger accumulation of blood lactate, growth hormone, and testosterone when volume was matched to that of the reduced tempos. Overall, evidence supports eccentric actions of < 2 s duration to improve subsequent concentric performance. There is no clear difference between using eccentric tempos of 2-6 s if the aim is to increase hypertrophic response and strength. Future research should analyse the performance of eccentric actions at greater velocities or reduced time durations to determine more factors such as strength response. Tempo studies should aim to complete the same TUT for protocols to determine measures for hypertrophic response.

The effects of exercise on kidney injury: the role of SIRT1

In patients with kidney injury, muscle mass and strength decrease with altered muscle protein synthesis and degradation along with complications such as inflammation and low physical activity. A treatment strategy to maintain muscle metabolism in kidney injury is important. One of the proposed strategies in this regard is exercise, which in addition to inducing muscle hypertrophy, reducing plasma creatinine and urea and decreasing the severity of tubal injuries, can boost immune function and has anti-inflammatory effects. One of the molecules that have been considered as a target in the treatment of many diseases is silent information regulator 1 (SIRT1). Exercise increases the expression of SIRT1 and improves its activity. Therefore, studies that examined the effect of exercise on kidney injury considering the role of SIRT1 in this effect were reviewed to determine the direction of kidney injury research in future regarding to its prevalence, especially following diabetes, and lack of definitive treatment. In this review, we found that SIRT1 can be one of renoprotective target pathways of exercise. However, further studies are needed to determine the role of SIRT1 in different kidney injuries following exercise according to the type and severity of exercise, and the type of kidney injury.

Effect of different eccentric tempos on hypertrophy and strength of the lower limbs

The purpose of this study was to evaluate the effects of altering the duration of the eccentric phase in isotonic contractions on muscle hypertrophy and strength of the quadriceps femoris. Ten healthy young adults (8 men and 2 women: Height: 173.3 ± 9.6 cm: Body mass: 69.84 ± 10.88 kg; Body fat: 19.47 ± 8.42%; Age: 25.3 ± 4.8 years) performed unilateral isotonic knee extension exercise, whereby each leg was randomly allocated to perform the eccentric phase of movement with a duration of either 2 seconds (G2S) or 4 seconds (G4S). Both conditions carried out the concentric phase of each repetition at a 1 second duration with no rest in the transition phases. Each condition performed 5 sets using 70% of 1 repetition maximum until muscle failure with 3 minutes of rest between sets for 8 weeks. The change in muscle strength was assessed by 1RM knee extension and muscle thickness was assessed by A-mode ultrasound. For each outcome variable, linear mixed-effects models were fit using restricted maximum likelihood. Hedges’ g effect sizes were calculated to provide insights into the magnitude of effects. Results showed all muscles increased in size over time; mean effects were similar in all muscles except for the vastus medialis, which favored the G4S condition. Conversely, only a trivial and highly variable effect was observed between interventions for strength gain. Our results suggest different eccentric durations produce similar increases in hypertrophy of the vastus lateralis and rectus femoris; however, the vastus medialis showed greater growth from the slower eccentric duration. Eccentric duration did not differentially affect strength-related adaptations.

Effects of resistance training on hypertrophy, strength and tensiomyography parameters of elbow flexors: role of eccentric phase duration

The aim of the study was to compare the effects of two different training protocols, which differ in the duration of the eccentric phase, on the one-repetition maximum (1RM), thickness and contractile properties of elbow flexors. Twenty untrained college students were randomly divided into two experimental groups, based on the training tempo: FEG (Faster Eccentric Group: 1/0/1/0) and SEG (Slower Eccentric Group: 4/0/1/0). Training intervention was a biceps bending exercise, conducted twice a week for 7 weeks. The intensity (60–70% RM), sets (3–4) and rest intervals (120 s) were held constant, while repetitions were performed until it was not possible to maintain a set duration. In the initial and final measurements, 1RM, muscle thickness and tensiomyography parameters – contraction time (Tc) and radial deformation (Dm) – were evaluated. An ANCOVA model (using baseline outcomes as covariates) was applied to determine between-group differences at post-test, while Pearson’s product-moment correlation coefficient was used to investigate the relationship between absolute changes in muscle thickness and Dm. Muscle strength increase was greater for SEG than for FEG (6.0 ± 1.76 vs. 3.30 ± 2.26 kg, p < 0.01). In both groups muscle thickness increased equally (FEG: 3.24 ± 2.01 vs. SEG: 3.57 ± 1.17 mm, p < 0.01), while an overall reduction in Dm was observed (FEG: 1.99 ± 1.20 vs. SEG: 2.26 ± 1.03 mm, p < 0.01). Values of Tc remained unchanged. A significant negative relationship was observed between changes in muscle thickness and Dm (r = -0.763, Adj.R² = 0.560, p < 0.01). These results indicate that the duration of the eccentric phase has no effect on muscle hypertrophy in untrained subjects, but that slower eccentric movement significantly increases 1RM.

Eccentric Force-Velocity Characteristics during a Novel Squat Protocol in Trained Rugby Union Athletes-Pilot Study

Eccentric strength characteristics have been shown to be important factors in physical performance. Many eccentric tests have been performed in isolation or with supramaximal loading. The purpose of this study was to investigate within- and between- session reliability of an incremental eccentric back squat protocol. Force plates and a linear position transducer captured force-time-displacement data across six loading conditions, separated by at least seven days. The reliability of eccentric specific measurements was assessed using coefficient of variation (CV), change in mean, and intraclass correlation coefficient (ICC). Eccentric peak force demonstrated good ICC (≥0.82) and TE (≤7.3%) for each load. Variables based on mean data were generally less reliable (e.g., mean rate of force development, mean force, mean velocity). This novel protocol meets acceptable levels of reliability for different eccentric-specific measurements although the extent to which these variables affect dynamic performance requires further research.

Equalization of Training Protocols by Time Under Tension Determines the Magnitude of Changes in Strength and Muscular Hypertrophy

Martins-Costa, HC, Lacerda, LT, Diniz, RCR, Lima, FV, Andrade, AGP, Peixoto, GH, Gomes, MC, Lanza, MB, Bemben, MG, and Chagas, MH. Equalization of training protocols by time under tension determines the magnitude of changes in strength and muscular hypertrophy. J Strength Cond Res XX(X): 000-000, 2021-The aim of this study was to investigate the effects of 2 training protocols equalized by tension (TUT) on maximal strength (1 repetition maximum [RM]), regional cross-sectional areas (proximal, middle, and distal), and total cross-sectional areas (sum of the regional cross-sectional areas) of the pectoralis major and triceps brachii muscles. Thirty-eight men untrained in resistance training participated in the study and were allocated under 3 conditions: Protocol 3s (n = 11; 12 repetitions; 3s repetition duration), Protocol 6s (n = 11; 6 repetitions; 6s repetition duration), and Control (n = 11; no training). Training protocols (10 weeks; bench press exercise) were equated for TUT (36 seconds per set), number of sets (3-4), intensity (50-55% of 1RM), and rest between sets (3 minutes). Analysis of variance was used to examine a percentage change in variables of interest across the 3 groups with an alpha level of 0.05 used to establish statistical significance. Protocols 3s and 6s showed no differences in the increase of total and regional muscle cross-sectional areas. There were no differences in regional hypertrophy of the pectoralis major muscle. In the triceps brachii muscle, the increase in distal cross-sectional area was greater when compared with the middle and proximal regions. Both experimental groups had similar increases in the 1RM test. In conclusion, training protocols with the same TUT promote similar strength gains and muscle hypertrophy. Moreover, considering that the protocols used different numbers of repetitions, the results indicate that training volumes cannot be considered separately from TUT when evaluating neuromuscular adaptations.

Does Varying Repetition Tempo in a Single-Joint Lower Body Exercise Augment Muscle Size and Strength in Resistance-Trained Men?

Pearson, J, Wadhi, T, Barakat, C, Aube, D, Schoenfeld, BJ, Andersen, JC, Barroso, R, Ugrinowitsch, C, and De Souza, EO. Does varying repetition tempo in a single-joint lower body exercise augment muscle size and strength in resistance-trained men? J Strength Cond Res XX(X): 000-000, 2021-This study compared the effects of FAST and SLOW eccentric repetition tempo in a single exercise volume-matched intervention on muscle thickness (MT) and strength in resistance-trained men. Using a within-subject design, 13 subjects had each leg randomly assigned to SLOW (1-0-3) or FAST (1-0-1) repetition tempo. Subjects underwent an 8-week strength-training (ST) intervention performed twice weekly. Unilateral leg-extension one repetition-maximum (1RM) and anterior thigh MT at the proximal (MTP) and distal (MTD) portions were assessed via ultrasound imaging at baseline and after 8 weeks of RT. Rating of perceived exertion (RPE) assessments of the training sessions (i.e., 16 per leg) were averaged for further analysis. Both legs similarly increased MTP (estimated differences: FAST: 0.24 cm, 3.6%; SLOW: 0.20 cm, 3.1%). However, for MTD, analysis of covariance analysis showed a leg effect (p = 0.02) in which absolute pre-to-post change was greater in FAST compared with SLOW (estimated differences: FAST 0.23 cm, 5.5%; SLOW: 0.13 cm, 2.2%). For 1RM, both legs similarly increased maximum strength (estimated differences: FAST: 9.1 kg, 17.0%; SLOW: 10.4 kg, 22.1%, p <= 0.0001). The SLOW group had a higher RPE than FAST (8.59 vs. 7.98, p = 0.002). Despite differences in RPE, our results indicate that both repetition tempos produced similar muscular adaptations. However, they also suggest that the FAST tempo may provide a small hypertrophic advantage at the distal quadriceps. From a practical standpoint, strength and conditioning professionals may implement a FAST tempo at least in one single-joint exercise during an 8-week training period to enhance regional hypertrophic adaptations in trained individuals.

The Effects of Different Types of Eccentric Overload Training on Strength, Speed, Power and Change of Direction in Female Basketball Players

The aim of this study was to investigate the effect of two types of eccentric (ECC) overload training on strength, speed, power and change of direction in female basketball players. Twenty amateur basketball players (mean ± SD: age: 23.67 ± 6.05 years; height: 1.73 ± 0.05 m; body mass: 80.28 ± 17.67 kg) participated in a randomized trial. The players performed either flywheel inertial training (FIT) (n = 11) or tempo ECC training (TET) (n = 9) for 4 weeks, performing two sessions weekly. Performance characteristics, one repetition back squat (1RM), counter-movement jump (CMJ), squat jump (SJ), 10-metre sprint (10 m), change of direction (COD) and sit and reach flexibility (S&R) were tested pre and post intervention. Post-hoc testing revealed significant improvements in the FIT group for 1RM (p ≤ 0.001; ES = 0.59), 10 m (p = 0.003; ES = -0.54) and CMJ (p ≤ 0.001; ES = 1.04), while significant improvements were revealed in the TET group for 1RM (p = 0.007; ES = 0.71) and S&R (p ≤ 0.001; ES = 0.58). In conclusion, both FIT and TET groups demonstrated a positive training stimulus for increasing muscular strength. FIT may produce superior adaptions in CMJ and 10-m sprint, while TET may produce superior adaptions in S&R. Neither group achieved increases in either SJ or COD.

Maximizing Muscle Hypertrophy: A Systematic Review of Advanced Resistance Training Techniques and Methods

BACKGROUND

Effective hypertrophy-oriented resistance training (RT) should comprise a combination of mechanical tension and metabolic stress. Regarding training variables, the most effective values are widely described in the literature. However, there is still a lack of consensus regarding the efficiency of advanced RT techniques and methods in comparison to traditional approaches.

METHODS

MEDLINE and SPORTDiscus databases were searched from 1996 to September 2019 for all studies investigating the effects of advanced RT techniques and methods on muscle hypertrophy and training variables. Thirty articles met the inclusion criteria and were consequently included for the quality assessment and data extraction.

RESULTS

Concerning the time-efficiency of training, the use of agonist-antagonist, upper-lower body supersets, drop and cluster sets, sarcoplasma stimulating training, employment of fast, but controlled duration of eccentric contractions (~2s), and high-load RT supplemented with low-load RT under blood flow restriction may provide an additional stimulus and an advantage to traditional training protocols. With regard to the higher degree of mechanical tension, the use of accentuated eccentric loading in RT should be considered. Implementation of drop sets, sarcoplasma stimulating training, low-load RT in conjunction with low-load RT under blood flow restriction could provide time-efficient solutions to increased metabolic stress.

CONCLUSIONS

Due to insufficient evidence, it is difficult to provide specific guidelines for volume, intensity of effort, and frequency of previously mentioned RT techniques and methods. However, well-trained athletes may integrate advanced RT techniques and methods into their routines as an additional stimulus to break through plateaus and to prevent training monotony.

Implementing Eccentric Resistance Training-Part 1: A Brief Review of Existing Methods

The purpose of this review was to provide a physiological rationale for the use of eccentric resistance training and to provide an overview of the most commonly prescribed eccentric training methods. Based on the existing literature, there is a strong physiological rationale for the incorporation of eccentric training into a training program for an individual seeking to maximize muscle size, strength, and power. Specific adaptations may include an increase in muscle cross-sectional area, force output, and fiber shortening velocities, all of which have the potential to benefit power production characteristics. Tempo eccentric training, flywheel inertial training, accentuated eccentric loading, and plyometric training are commonly implemented in applied contexts. These methods tend to involve different force absorption characteristics and thus, overload the muscle or musculotendinous unit in different ways during lengthening actions. For this reason, they may produce different magnitudes of improvement in hypertrophy, strength, and power. The constraints to which they are implemented can have a marked effect on the characteristics of force absorption and therefore, could affect the nature of the adaptive response. However, the versatility of the constraints when prescribing these methods mean that they can be effectively implemented to induce these adaptations within a variety of populations.