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Different methods can be used to assess muscle hypertrophy, but the effects of training on regional changes in muscle size can be detected only using direct muscle measurements such as muscle thickness, cross-sectional area, or volume. Importantly, muscle size increases vary across regions within and between muscles after resistance training programs (i.e., heterogeneous, or nonuniform, muscle hypertrophy). Muscle architectural changes, including fascicle length and pennation angle, after resistance and stretch training programs are also region-specific. In this paper, we show that the literature indicates that a single-site measure of muscle shape does not properly capture the effects achieved after exercise training interventions and that conclusions concerning the magnitude of muscle adaptations can vary substantially depending on the muscle site to be examined. Thus, we propose that measurements of muscle size and architecture should be completed at multiple sites across regions between the agonist muscles within a muscle group and along the length of the muscles to provide an adequate picture of training effects. [ABSTRACT FROM AUTHOR]

The purpose of this investigation was to compare the effects of 2 different periodized resistance training programs on maximal strength, power, and muscle architecture, in trained individuals. Twenty-two resistance-trained men were randomly assigned to either a mixed session training group (MSP; n = 11; age = 23.7 ± 2.6 years; body mass = 80.5 ± 9.8 kg; height = 175.5 ± 6.1 cm) or a block periodization group (BP; n = 11; age = 25.7 ± 4.6 years; body mass = 81.1 ± 10.7 kg; height = 176.8 ± 8.4 cm). Both training programs were 10 weeks in duration and were equated in volume. Each training session of the MSP focused on power, maximal strength, and hypertrophy, whereas each mesocycle within the BP focused on one of these components. Subjects were assessed for body composition, muscle architecture, maximal strength, and power. In addition, perceived training load, and training volume were calculated. Subjects in MSP experienced greater improvements in fat free mass (p = 0.021), muscle thickness of the pectoralis and vastus lateralis (p < 0.05), and a greater improvement in 1RM bench press (p < 0.001; +8.6% in MSP and +2% in BP) than in BP. By contrast, BP resulted in greater improvements in vertical jump (p = 0.022; +7.2%) compared with MSP (+1.2%). No significant differences were noted between the groups for perceived training load (p = 0.362) nor training volume (p = 0.169). Results of this study indicated that in a 10-week training study, MSP may enhance muscle hypertrophy and maximal strength to a greater extent than BP, with the same training volume and perceived training load. However, BP may be more effective for vertical jump improvement. [ABSTRACT FROM AUTHOR]

Coratella, G, Beato, M, Bertinato, L, Milanese, C, Venturelli, M, and Schena, F. Including the eccentric phase in resistance training to counteract the effects of detraining in women: a randomized controlled trial. J Strength Cond Res 36(11): 3023–3031, 2022—The current study compared the effects of concentric-based (CONC), eccentric-based (ECC), and traditional concentric-eccentric (TRAD) resistance training on muscle strength, mass, and architecture and the postdetraining retention of the training-induced effects in women. Sixty women were randomly assigned to unilateral volume-equated CONC, ECC, or TRAD knee extension training or control (N = 15 per group). Before training, after an 8-week intervention period, and after an 8-week detraining period, isokinetic concentric, eccentric, and isometric torque were measured. In addition, thigh lean mass was assessed by dual X-ray absorptiometry and vastus lateralis thickness, pennation angle, and fascicle length by ultrasound. After training, concentric and isometric torque increased (p < 0.05) similarly in all groups, whereas eccentric torque increased more in ECC than that in CONC (+13.1%, effect size (ES): 0.71 [0.04–1.38]) and TRAD (+12.6%, ES: 0.60 [0.12–1.08]). Thigh lean mass increased in ECC (+6.1%, ES: 0.47 [0.27–0.67]) and TRAD (+3.1%, ES: 0.33 [0.01–0.65]). Vastus lateralis thickness and pennation angle increased (p < 0.05) similarly in all groups, whereas fascicle elongation was visible in ECC (+9.7%, ES: 0.92 [0.14–1.65]) and TRAD (+7.1%, ES: 0.64 [0.03–1.25]). After detraining, all groups retained (p < 0.05) similar concentric torque. ECC and TRAD preserved eccentric torque (p < 0.05), but ECC more than TRAD (+17.9%, ES: 0.61 [0.21–1.21]). All groups preserved isometric torque (p < 0.05), but ECC more than CONC (+14.2%, ES: 0.71 [0.04–1.38]) and TRAD (+13.8%, ES: 0.65 [0.10–1.20]). Thigh lean mass and vastus lateralis fascicle length were retained only in ECC (p < 0.05), pennation angle was preserved in all groups (p < 0.05), and thickness was retained in CONC and ECC (p < 0.05). Including the eccentric phase in resistance training is essential to preserve adaptations after detraining. [ABSTRACT FROM AUTHOR]

Previous investigations of 1 repetition maximum bench press (1RM BP) performance have been either descriptive or have explored a limited number of contributing variables. The purpose of this study was to investigate the interplay between structural, technical, and neuromuscular factors in relation to 1RM BP in competitive powerlifters. Thirteen national and international level male powerlifters (26 ± 9 years, 178 ± 6 cm, and 93.8 ± 9.9 kg) visited the laboratory twice. Anthropometric and ultrasound measures were taken on the first visit, whereas performance measures (voluntary activation level, isokinetic strength, and kinetic, kinematic, and electromyographic measurements during 1RM BP) were recorded on the second visit. Correlation and multiple regression were used to investigate the contribution of structural, technical, and neuromuscular variables to 1RM BP corrected for body mass using the Wilks coefficient. The highest degree of association was shown for structural (lean and bone mass, brachial index, arm circumference, and agonist cross-sectional area [CSA]; r = 0.58-0.74) followed by neuromuscular factors (elbow and shoulder flexion strength; r = 0.57-0.71), whereas technical factors did not correlate with 1RM BP performance (r ≤ 0.49). The multiple regression showed that lean body mass, brachial index, and isometric shoulder flexion torque predicted 59% of the common variance in 1RM BP. These data suggest that in a sample of elite competitive powerlifters, multiple factors contribute to 1RM BP with variables such as lean body mass, the agonist CSA, brachial index, and strength of the elbow and shoulder flexors being the greatest predictors of performance. [ABSTRACT FROM AUTHOR]

The aim of this study was to compare the effects of active and passive strategies on the recovery response after a high-volume bench press protocol. Twenty-five resistance-trained men (mean 6 SD: age = 25.8 6 3.6 years; body mass = 87.1 6 12.1 kg; and height = 177.4 6 4.9 cm) performed a high-volume bench press session (8 sets of 10 reps at 70% of 1 repetition maximum). Subsequently, they were randomly assigned to an active recovery (AR) group (n = 11) or to a passive recovery (PR) group (n = 14). Active recovery consisted of light bench press sessions performed 6 hours and 30 hours after the high-volume exercise protocol. Muscle performance (bench throw power [BTP] and isometric bench press [IBP]) and morphology (muscle thickness of pectoralis major [PECMT] and of triceps brachii [TRMT]) were measured before exercise (baseline [BL]), and at 15-minute (15P), 24-hour (24P), and 48-hour (48P) postexercise. Post-exercise recovery of both maximal strength and power was accelerated in AR compared with PR. Both BTP and IBP were significantly (p, 0.001) reduced at 15P and 24P in PR, whereas changes were significant (p, 0.001) at 15P only in AR. PECMT was still significantly (p = 0.015) altered from BL at 48P in PR, whereas changes were significant (p, 0.001) at 15P only in AR. No significant interactions (p . 0.05) between PR and AR were detected for TRMT and muscle soreness. The present results indicate that AR enhances the recovery rate after high-volume exercise sessions and may be included in resistance training programs to optimize muscle adaptations. [ABSTRACT FROM AUTHOR]

The aim of this study was to compare the changes in gastrocnemius muscle thickness (MT) between conditions such as which foot was pointed outward (FPO), foot was pointed inward (FPI), or foot was pointed forward (FPF). Twenty-two young men (23 ± 4 years) were selected and performed a whole-body resistance training program 3 times per week for 9 weeks, with differences in the exercise specific for calves. The calf-raise exercise was performed unilaterally, in a pin-loaded seated horizontal leg-press machine, in 3 sets of 20-25 repetitions for training weeks 1-3 and 4 sets for weeks 4-9. Each subject's leg was randomly assigned for 1 of the 3 groups according to the foot position: FPO, FPI, and FPF. Measurements with a B-mode ultrasound were performed to assess changes in MT of medial and lateral gastrocnemius heads. After the training period, there were observed increases in MT of both medial (FPO = 8.4%, FPI = 3.8%, and FPF = 5.8%) and lateral (FPO 5 5.5%, FPI = 9.1%, and FPF = 6.4%) gastrocnemius heads, and significant differences for magnitude of the gains were observed between FPO and FPI conditions (p < 0.05). Positioning FPO potentiated the increases in MT of the medial gastrocnemius head, whereas FPI provided greater gains for the lateral gastrocnemius head. Our results suggest that head-specific muscle hypertrophy may be obtained selectively for gastrocnemius after 9 weeks of calf training in young male adults. [ABSTRACT FROM AUTHOR]

Mizuno, T. Combined effects of static stretching and electrical stimulation on joint range of motion and muscle strength. J Strength Cond Res 33(10): 2694-2703, 2019-The purpose of this study was to examine the effects of the combination of static stretching (SS) and electrical stimulation (ES) for 8 weeks on joint range of motion (ROM), muscle strength, and muscle architecture. Thirty-one subjects were divided into 3 groups: the SS combined with ES (SS + ES) group, SS group, and control group. The SS + ES group performed calf stretching simultaneously with ES to the gastrocnemius medialis, whereas the SS group performed calf stretching only. The training regimen consisted of four 30-second sets of stretching, with 30-second rest intervals, 3 days per week for 8 weeks. The control group did not perform any intervention exercise. Before and after training, measurements were taken to determine the ankle ROM, plantar flexion 1 repetition maximum strength, muscle thickness, pennation angle, and circumference of the lower leg. The results showed that 8 weeks of training led to significant improvements in the ankle ROM and muscle thickness in both the SS + ES and SS groups. There were significant increases in plantar flexion 1 repetition maximum strength and pennation angle in all 3 groups. For all parameters, there was no difference between the SS + ES and SS groups. These results clarify that 8 weeks of SS improves joint ROM and muscle thickness and shows that there is no additional benefit gained by combining ES with SS in this particular training regime. [ABSTRACT FROM AUTHOR]

The purpose of this study was to elucidate the effects of compression garments (CG) on controlled force output after strenuous exercise. Sixteen healthy volunteers completed trials both with CG and without CG (control trial: CON) on 2 separate, random days which were at least 1 month apart. Both trials required participants to perform heel-rise exercises from maximal dorsiflexion to maximal plantar flexion 20 times with a single leg. The subjects repeated 3 sets of the exercise and took a rest for 2 minutes between sets. Before and after the heel-rise exercise, mechanical (stiffness) and architectural properties of the gastrocnemius medialis muscle were evaluated using the ultrasound method. Also, isometric maximal voluntary contraction (MVC) of plantar flexion was measured, and the subjects maintained 20% MVC of plantar flexion torque for 20 seconds as steadily as possible (steadiness task) as an index of force control. Repeated 2-way analysis of variance analysis (CG/CON x time) indicated that all the parameters declined immediately after heel-rise exercise in both CG and CON trials. Maximal voluntary contraction did not show different tendencies between CG and CON trials, but muscle stiffness and steadiness declined less in CG than CON (p < 0.05). In conclusion, CG are considered to positively benefit controlled force output after strenuous exercise. [ABSTRACT FROM AUTHOR]

The purpose of this study was to examine changes in muscle architecture and jumping performance in NCAA division I women's volleyball players throughout a competitive season and in preparation for conference championships. Ten women volleyball players were tested at preseason (T1), pretaper (T2), and post-taper (T3) on measures of vastus lateralis muscle thickness (MT), pennation angle (PA) and fascicle length (FL) using ultrasonography, and unloaded and loaded squat jump height (SJH) and peak power allometrically scaled to body mass (SJPPa) on a force platform. Rating of perceived exertion training load and strength training volume load were monitored weekly. Player's MT (p < 0.001, Glass's Δ = 2.8) and PA increased (p = 0.02, Δ = 3.9) after in-season training. However, MT decreased after the taper (p = 0.01, Δ = 0.6) but remained elevated above preseason values (p < 0.001, Δ = 1.7). There were no statistical changes in FL, SJH, or SJPPa. Large-to-very large negative relationships (r = -0.51 to -0.81) were observed between preseason relative maximal strength and changes in SJH and SJPPa with various loads over the season. These findings demonstrate that relatively low volumes of strength training and concurrent sport training during a tapering period are capable of preserving jumping performance, but not MT in women's volleyball players; however, jumping performance changes seem to be related to the player's strength level. Stronger players may benefit from an overreaching microcycle before the taper to preserve previously accrued muscular adaptations and jumping performance. [ABSTRACT FROM AUTHOR]

Loaded vertical jumps are routinely used to enhance athlete's power production in the lower extremity and to optimize jumping and sprinting performance. This study compared traditional (TP) and daily undulating (DUP) periodization on muscle strength, jumping performance, electromyographic (EMG) muscle activity, and muscle architecture during preseason loaded jump training. Twenty-two athletes from different team sports (age: 24.3 ± 2.6 years, height: 175.9 ± 7.5 cm, body mass: 72.2 ± 8.4 kg, 12 males/10 females, strength training experience: 5.1 ± 2.2 years) performed 6 weeks of loaded countermovement jumping (CMJ) (18 sessions) during which subjects arranged the experimental training loads with either TP or DUP. Therefore, loading conditions corresponding to 0, 15, and 30% of individual body mass were used by manipulating weighted training vests and the intensity zones and training volume were equated between the groups. Pre- to post-training, center of mass (COM) maximal CMJ performance, isometric maximal voluntary contractive capacity of the leg extensors (MVC), EMG maximal voluntary muscle activity of knee extensor muscles, and vastus lateralis and rectus femoris muscle architecture were examined. Repeated measures multivariate analysis of variances (MANOVA with factors: time x training group) revealed moderate (5-16%) but significant (p ≤ 0.006) temporal increases in COM jumping height, leg extensor MVC and muscle architecture in both groups. Importantly, these temporal alterations were similar using either TP or DUP. Therefore, our data indicate that both periodization models can be effectively applied to increase leg extensor strength, vertical jumping performance, and muscle architecture during short-term preseason loaded jump training. [ABSTRACT FROM AUTHOR]

The article presents a study to compare the results of effects of compound and complex resistance training on several physiological factors among healthy men including performance of high-speed movement, strength and composition of the muscles. Several exercises that young men performed includes bench press, machine box squats and jumping exercises.

The article reports on research which investigated which physiological assessments best predicted high-intensity running (HIR) performance during a women's collegiate soccer game. Researchers evaluated 10 women soccer players. They found that maximal oxygen uptake and muscle architecture may predict HIR distance during a competition.

The article discusses a study of ecologically valid resistance training protocols that considers the impact of range of motion on muscle size, strength, and subcutaneous fat. It suggests that range of motion should not be compromised for external loading. Topics include muscle architecture and strength training.

The article presents a study which determined the force-length biomechanical differences between incline and plane hopping performance. The researchers investigated the jumping performances and ground reaction forces of active men in both incline and plane surfaces. The study found no temporal characteristics in incline and plane hopping, however, incline hopping could induce ankle dorsiflexion and knee extension at takeoff.