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Background and Study Aim. The aim of this study is to examine the electromyographic responses to Nordic curl and prone leg curl exercises, having two different mechanics. Material and Methods. The athletes performed the prone leg curl and Nordic curl exercises in random order, 6 repetitions each. Electromyographic data of semimemranosus, semitendinosus, biceps femoris and rectus femoris muscles were recorded by 8-channel electromyography in order to examine the muscle responses to exercises. Total duration of exercise, cumulative integrated electromyographic values and muscle activation rates in 5 different intensity zones determined according to MVC% values have been compared. Results. Prone leg curl exercise occurred in less time than Nordic curl exercise. According to the cumulative integrated electromyography data results, all muscles showed similar muscle activation in both exercises. Comparing the muscle activation rates in the five intensity zones, more muscle activity was observed for Nordic curl exercise in the first intensity zone, while prone leg curl exercise was more active in the third and fourth zones. During the prone leg curl exercise, the muscle activation rate of the dominant leg is higher in the first intensity zone, whereas the non-dominant leg in the fourth intensity zone has a higher muscle activation. During the Nordic curl exercise, the muscle activation rates of the dominant leg in the first and fifth intensity zones are higher, whereas the nondominant leg in the fourth intensity zone is higher. Conclusions. Prone leg curl exercises can be preferred in order to stimulate high muscle activation in a short time. Comparing the two exercises there was no significant difference in muscle activity in dominant and nondominant legs.

The purpose of the present study was to investigate effects of type of exercise on the muscle strength and functional performance gains for lower-body in older adults after heavy resistance training. Twenty untrained older adults volunteers (8 men and 12 women) were randomized and placed into two groups: multi-joint exercise—MJ (65 ± 6 years) and single-joint exercise—SJ (62 ± 6 years). Participants were tested twice during control period, and resistance training (RT) effects were assessed after six (middle), and 12 (post) weeks of RT. On test day it was performed a five-repetition maximum (5-RM) tests for leg press (LP), leg extension (LE) and seated leg curl (SLC); stand up 30 s test (SU30), climbing (CS) and down (DS) stairs; time up and go (TUG) and squat jump (SJ). Each group trained 24 sessions. Main effects within and between groups were assessed by Anova. There were increases from pre to middle and post-training (p 0.05). No significant changes were observed in the SJ variables after training period (p > 0.05). Multi- and single-joint exercises induced similar gains in the maximal strength and functional performance.

In this study, we aimed to analyze the magnitude and direction of inter-limb asymmetries in ankle dorsiflexion range of motion (ROM), power (using iso-inertial devices), and a neuromuscular skill (change of direction). Secondarily, we aimed to determine the relationship between inter-limb asymmetry scores for each test and also between these scores and the scores for the different performance tests. Sixteen semiprofessional male soccer players (age: 25.38 ± 6.08 years; body height: 1.78 ± 0.64 m; body mass: 79.5 ± 14.9 kg) participated in this study. We calculated inter-limb asymmetries using five tests: ankle dorsiflexion ROM, change of direction (COD 180º), and iso-inertial resistance tasks in the open (leg extension strength (LE), leg curl strength (LC)) and closed (crossover step (CRO)) kinetic chain. Our results showed that asymmetry magnitudes differed between all tests with highest inter-limb asymmetries displayed during iso-inertial overloading. In addition, we observed that the direction of asymmetries varied depending on the testspecificity, and that the CRO asymmetries had a negative association with LE and CRO performance. These findings highlight the independent nature of asymmetries and that CRO could be an appropriate test to detect asymmetries related with the performance of soccer-specific actions (such as changes of direction). Practitioners are encouraged to use multiple tests to detect existing inter-limb differences according to the specific characteristics of each sport. info:eu-repo/semantics/publishedVersion

The purpose of this study was to examine whether the NHE with an increased lower leg slope angle would enhance hamstring EMG activity in the final phase of the descend. The hamstring EMG activity was measured, the biceps femoris long head (BFlh) and the semitendinosus (ST). Fifteen male volunteers participated in this study. Subjects performed a prone leg curl with maximal voluntary isometric contraction to normalize the hamstring EMG activity. Subsequently, subjects performed the NHE, with the help of a certified strength and conditioning specialist, while the lower leg slope angle were randomly set at 0° (NH), 20° (N20), and 40° (N40). To compare hamstring EMG activity during the NHE variations, the knee flexion angle was set in the range from 0° to 50°, divided into five phases (0–10°, 10–20°, 20–30°, 30–40° and 40–50°), where 0° indicated that the knee was fully extended. To calculate the knee extension angular velocity, the knee flexion angle divided by time, and break point angle (BPA) was the angle at which 10°/s was exceeded. In the statistical analysis, a two-way repeated measures ANOVA was used for the hamstring EMG activity and a one-way repeated measures ANOVA was used for the BPA. The EMG activity of the BFlh and the ST in N20 and N40 was significantly higher than in NH at knee flexion angle of 0–20° (p < 0.05). For the BPA, NH (57.75° ± 13.28°), N20 (36.27° ± 9.89°) and N40 (16.26° ± 9.58°) were significantly higher in that order (p < 0.05). The results of this study revealed that the NHE with an increased lower leg slope angle shifted the BPA to the lower knee flexion angle and enhanced the hamstring EMG activity in the final phase of the descent.

The purpose of this study was to develop an equation to predict strength for seven common resistance training exercises using anthropometric and demographic measures. One-hundred forty-seven healthy adults (74 males, 73 females, 35 ± 12 yr, 174 ± 10 cm, 88 ± 19 kg) volunteered to participate. Body composition values (regional/total) and body dimensions were assessed using dual-energy x-ray absorptiometry (DEXA). Subjects underwent the following maximal strength assessments: Leg Press, Chest Press, Leg Curl, Lat Pulldown, Leg Extension, Triceps Pushdown, and Biceps Curl. Multiple linear regression with stepwise removal was used to determine the best model to predict maximal strength for each exercise. Independent predictor variables identified (p

This study is intended to investigate the effects of Phoneix Dactylifera pollen on markers of delayed-onset muscle soreness (DOMS) induced by eccentric resistance exercise in female athletes. Thirty-six female athletes were randomly selected and equally divided into 3 groups of 12 subjects, including: (1) 100 mg of P. dactylifera, (2) 200 mg of P. dactylifera, and (3) 100 mg of starch (placebo). Having received 10-day supplementation based on their groups label, all participants performed a bout of eccentric leg curl exercise by lying leg curl machine (five sets, three repetitions, each set with 110–130% one-repetition maximum, 1-min rest between sets). The blood samples were collected before and 1, 2, 3 and 4 days after the exercise. Data were analyzed using repeated measures analysis of variance (ANOVA) at a significance level of P

Supplemental digital content is available in the text., The biarticular hamstrings are lengthened more in a seated (hip-flexed) than prone (hip-extended) position. Purpose We investigated the effects of seated versus prone leg curl training on hamstrings muscle hypertrophy and susceptibility to eccentric exercise-induced muscle damage. Methods Part 1: Twenty healthy adults conducted seated leg curl training with one leg (Seated-Leg) and prone with the other (Prone-Leg), at 70% one-repetition maximum (1RM), 10 repetitions per set, 5 sets per session, 2 sessions per week for 12 wk. Magnetic resonance imaging (MRI)–measured muscle volume of the individual and whole hamstrings was assessed pre- and posttraining. Part 2: Nineteen participants from part 1 and another 12 untrained controls (Control-Leg) performed eccentric phase-only leg curl exercise at 90% 1RM, 10 repetitions per set, 3 sets for each of the seated/prone conditions with each leg. MRI-measured transverse relaxation time (T2) and 1RM of seated/prone leg curl were assessed before, 24, 48, and 72 h after exercise. Results Part 1: Training-induced increases in muscle volume were greater in Seated-Leg versus Prone-Leg for the whole hamstrings (+14% vs +9%) and each biarticular (+8%–24% vs +4%–19%), but not monoarticular (+10% vs +9%), hamstring muscle. Part 2: After eccentric exercise, Control-Leg had greater increases in T2 in each hamstring muscle (e.g., semitendinosus at 72 h: +52%) than Seated-Leg (+4%) and Prone-Leg (+6%). Decreases in 1RM were also greater in Control-Leg (e.g., seated/prone 1RM at 24 h: −12%/−24%) than Seated-Leg (0%/−3%) and Prone-Leg (+2%/−5%). None of the changes significantly differed between Seated-Leg and Prone-Leg at any time points. Conclusion Hamstrings muscle size can be more effectively increased by seated than prone leg curl training, suggesting that training at long muscle lengths promotes muscle hypertrophy, but both are similarly effective in reducing susceptibility to muscle damage.

Most strength and conditioning coaches deal with the question in the training plan, how to supplement specific exercises, or which non-specific exercises would be the most suitable for achieving the set purpose. This study aims to assess what strength transfer with a focus on the lower limbs is projected from the selected strength intervention program (the right leg exercises only single-joint exercises: leg extension on machine and leg curl; the left leg exercises only multi-joint exercises: deadlift and leg press) to the force of the knee joint flexors and extensors during the eccentric and the concentric contraction. In one training session, the participants repeated every exercise five times in four series. The load intensity was around 90% of 1RM and was increased by 5% after the first and the fifth week. The rest interval was always three minutes long. For the left lower limb, the highest transfer (0.20) was from the leg press to the knee joint extensor at the eccentric contraction and from the deadlift was the highest transfer (0.19) to the knee joint extensor at the eccentric contraction. For the right lower limb, the highest transfer (0.53) was from the leg extension on a machine to the knee joint flexor at the concentric contraction and from the lying leg curl was the highest transfer (0.47) to the knee joint flexor at the concentric contraction.

This study aimed to analyze the influence of the inertial load on both concentric and eccentric power output production during the flywheel leg curl exercise, and to assess the reliability of power output variables. Sixteen participants (8 males, 8 females) attended 4 testing sessions. During testing, participants performed one set of eight repetitions using a specific inertial load (0.083, 0.132, 0.182, 0.266 and 0.350 kg·m2) with a flywheel leg curl exercise. Concentric (CON) power, eccentric (ECC) power and the ECC/CON ratio were analyzed. The reliability analysis between sessions was performed. A significant interaction of inertia load x gender was found in CON power (p < 0.001) and in ECC power (p = 0.004), but not in the ECC/CON ratio (p = 0.731). A significant with-in (inertia loads) effect was found in CON power (p < 0.001) and in ECC power (p < 0.001), but not in the ECC/CON ratio (p = 0.096). CON power showed very high reliability scores, ECC power showed high to very high reliability scores, while the ECC/CON ratio ranged from poor to moderate. A significant between gender effect was found in CON power (p < 0.001) and in ECC power (p < 0.001), but not in the ECC/CON ratio (p = 0.752). This study is the first to report that power output in the flywheel leg curl exercise is altered by the inertia load used, as well as power output is different according to gender. CON and ECC power output presents high to very high reliability scores, and the ECC/CON ratio should not be used instead. These results can have important practical implications for testing and training prescription in sports.

To gain more knowledge about the mechanism (i.e., mediators) of resistance exercise (RE)-induced improvements in physical performance (PP), we seek to investigate whether improvements in muscle strength (MS), muscle power (MP), and lean body mass (LBM) and (or) self-reported fatigue (SRF) are mediators of the effect of RE on PP in breast cancer survivor women (BCSW). The volunteers were randomly divided into two groups: control group (CT; n = 9) and resistance exercise (RE; n = 11). The RE protocol consisted of three sets in each exercise (leg extension, leg curl, 45° leg press, and calf raise), between 8 and 12 repetitions per set, with an estimated load of 80% of one-repetition maximum (1RM), and three times a week on non-consecutive days for 12 weeks. The CT group performed only stretching exercises twice a week. SRF, maximal muscle power (Pmax), MP, LBM, and PP were assessed using the Brief Fatigue Inventory Questionnaire; 1RM test; isoinertial dynamometer; DXA; and walking speed, sit-to-stand (STS), and timed up and go (TUG) test, respectively. Following 12 weeks, the RE group reduced SRF and increased MP, Pmax, LBM, and performance in all tests (walking speed, STS, and TUG) when compared with the CT group. There were significant associations of the changes in LBM, MS, Pmax, and SRF with changes in physical performance tests only in the RE group. Our findings suggest that improvements in LBM, MS, MP, and self-reported fatigue mediate the effect of resistance exercise on physical performance in BCSW.

The study compared the effects of resistance training programs composed by multi-joint (MJ), single-joint (SJ) and the combination of multi- and single-joint (MJ+SJ) exercises on muscle strength and hypertrophy in trained women. Thirty participants were divided into groups that performed only MJ exercises, SJ exercises and MJ+SJ exercises for six months. Participants were tested for 1-repetition maximum (RM) and muscle thickness (MT) before and after the intervention. All groups showed significant gains on 1RM tests from pre- to post-training (P

This randomised controlled study examined the force-velocity relationship changes (force and velocity axis intercepts, slope and estimated maximum power) in response to 5-week training programmes differing in the set configuration. For each session, the traditional group performed 4 sets of 8 repetitions with 5 min of rest between sets and exercises, while the cluster group completed 16 sets of 2 repetitions with 1 min of rest between sets and 5 min between exercises. Both programmes were performed with the 10-repetition maximum load, including bench press, parallel squat, lat pull-down and leg curl exercises. Individual force-velocity profiles were obtained for bench press and squat using a linear velocity transducer before and after the intervention, along with lactate and mechanical performance during the intervention. Results showed in bench press similar changes of the force-velocity profile after both protocols (no shift of the slope and higher force and velocity axis intercept values). For the squat, significant changes in the slope (P = 0.001) and the velocity intercept (P = 0.002) towards a velocity profile were observed after cluster but not after traditional training. These results suggest that set configuration may modulate changes of force-velocity relationship, especially for squat.

The aim of the current study is to compare the effects of hypertrophy-, strength-, and power-type resistance exercise training types on hydrogen peroxide (H2O2), malondialdehyde (MDA), total lactate dehydrogenase (LDH), and total creatine kinase (CK) in resistance-trained women. After determining one-repetition maximum (1-RM), ten resistance-trained women (age 26.30 ± 4.95 years; body mass index 22.07 ± 2.02 kg/m2; body fat 24.64 ± 4.98%) conducted hypertrophy-type (70% of 1-RM), strength-type (90% of 1-RM), and power-type (45% of 1-RM) resistance exercise for three consecutive weeks. The movements included lever leg extension, reverse-grip lat pull-down, horizontal leg press, standing biceps cable curl, lying leg curl, machine bench press, standing cable triceps extension, and seated calf raises. Fasting blood samples were obtained immediately before and immediately after each trial. Statistical analyses were performed using the t test, Wilcoxon, and analysis of covariance. The significance level was set at P

Sousa, AC, Gomes, TM, Sousa, MS, Saraiva, AR, Araujo, GS, Figueiredo, T, and Novaes, JS. Static stretch performed after strength training session induces hypotensive response in trained men. J Strength Cond Res 33(11): 2981-2990, 2019-The purpose of this study was to compare the acute effect of 3 different combinations between passive static stretching exercises (SE) with resistance training (RT) on blood pressure (BP) response in normotensive trained men. Twenty-six volunteer subjects (age: 26.1 ± 5.4 years; body mass: 86.5 ± 10.5 kg; height: 1.78 ± 0.6 cm) participated in this study. After assessing 10 repetition maximum loads for the bench press, lat pulldown, shoulder press, leg press, leg extension, and leg curl, the subjects were randomly assigned on 3 experimental conditions: (a) static SE were performed before the RT session (SE + RT); (b) static SE were performed after the RT session (RT + SE); and (c) static SE were performed between the RT session (RTSE). The BP was measured for 60 minutes after the RT session. The 2-way analysis of variance for repeated measures showed no significant difference (p > 0.05) between the experimental conditions. In within comparisons, only the RT + SE experimental condition did not cause significant increases (p = 0.07) on systolic blood pressure (SBP) when compared the baseline and post-test moments (132.2 ± 10.7 vs. 141.3 ± 18.1 mm Hg). In addition, hypotensive effects were found in SBP only in the RT + SE experimental condition when compared SBP baseline (132.2 ± 10.7 mm Hg) vs. SBP30 minutes (121.7 ± 11.8 mm Hg; p = 0.04), SBP45 minutes (120.6 ± 9.8 mm Hg; p = 0.03), and SBP60 minutes (120.0 ± 7.9 mm Hg; p = 0.00). These findings suggest that performing static SE after the RT session provide an ideal combination for a postexercise hypotensive response from 30 minutes after exercise (and this change was enhanced up to 60 minutes). In conclusion, strength and conditioning professionals can prescribe static SE after RT if the goal is to reduce blood pressure after training.

Aging is related to negative changes in muscle strength and consequent impairment in daily activities. A number of studies have demonstrated that resistance training (RT) is promising for disease prevention and rehabilitation in this population. The objective of the present study was to investigate the effects of a four-exercise RT protocol on the functional parameters of sedentary elderly women. The study sample consisted of 29 elderly women (aged 68.4 ± 5.2 years). Before and after 10 weeks of RT, the following evaluations were performed: 10-m walking, standing up from the sitting position five times, standing up from the sitting position for 30 s, standing up from the ventral decubitus position, standing up from a chair and walking inside the house, and dressing and undress a t-shirt. RT was performed for 10 weeks (2 times per week with a rest interval of 48 h between each session). The protocol consisted of performing leg press at 45°, seated row, leg curl and bench press alternated by segment, performed with a 2-min rest interval between sets and exercises. Significant improvements were found for the following tests: 10-m walking (6.5 ± 1.2 vs. 5.8 ± 1.1 s; p = 0.001), standing up from the sitting position (8.6 ± 2.3 vs. 6.9 ± 1.4 s; p = 0.001), 30-s chair-stand (19.5 ± 5.0 vs. 23.8 ± 5.3 repetitions; p = 0.001), dressing and undressing a t-shirt (9.7 ± 1.8 vs. 9.0 ± 1.9 s; p = 0.025), standing up from the ventral decubitus position (3.6 ± 1.0 vs. 3.3 ± 0.9 s; p = 0.003) of elderly. The four-exercise RT protocol was effective in improving functional parameters in the present study sample.

To investigate the influence of internal and external foot rotation on medial and lateral hamstring electromyographic (EMG) activity during conventional hamstring exercises in patients following anterior cruciate ligament (ACL) reconstruction.Cross-sectional study.EMG activity of medial and lateral hamstrings was recorded during prone leg curl, single-leg bridge and Nordic hamstring exercises with three different foot positions (neutral, internal rotation, external rotation), randomly presented.Twenty patients 9-15 months after ACL reconstruction with the semitendinosus-gracilis graft.Concentric and eccentric EMG activity normalized to the EMG activity recorded during a maximal voluntary contraction (MVC).Compared to the neutral position, the EMG activity of the medial hamstring during prone leg curl exercise was significantly increased by internal foot rotation (concentric: +8.7% MVC; eccentric: +5.9% MVC; p 0.01; d = 0.88-0.99) and decreased by external rotation (concentric: 5.8% MVC; eccentric: 5.2% MVC; p 0.05; d = 0.67-0.92). Foot position did not significantly affect hamstring EMG activity during single-leg bridge and Nordic hamstring exercises.Active internal rotation of the foot during prone leg curl exercise can help selectively maximize muscle activity of the medial hamstring portion. This may have implications for post-operative rehabilitation of ACL patients with a semitendinosus-gracilis graft.

The aim of this study was to compare the effects of resistance training of low volume and high intensity with or without photobiomodulation (PBM) on muscle strength and functional performance in post-menopausal women. Thirty-four post-menopausal women were randomized into resistance training (RTG, n = 17) or resistance training plus PBM (PBMG, n = 17). Individuals from both groups received the same RT protocol consisting of leg-press 45°, front lat pulldown, leg curl, chest press, and squat performed in two sets of 10 repetitions with a workload of 75% of one repetition maximum (1RM), twice per week, during 8 weeks. PBMG individuals also received, prior to the exercise session, PBM through a cluster containing 7 visible diodes (630 nm) and 7 infrared diodes (850 nm) with power of 100 mW each and energy of 4 J per diode, applied to the quadriceps femoris muscle; individuals from RTG received placebo PBM prior to the sessions, applied with the same device switched off. Muscle strength (1RM; isometric dynamometer), functional performance (Time Up and Go; Berg Balance Scale; 6-min walk test), and quality of life (World Health Organization Quality of Life-Bref) were performed before and after 8 weeks. Both groups increased muscle strength (p

The use of progressive strength training among the elderly has become an accepted part of evidence-based practice for preventive and rehabilitative care. Exercise is undoubtedly one of the pillars for resilient aging. While research has shown impressive outcomes from strength training, the challenge remains to get elderly persons to exercise. Here we describe a Finnish-Singaporean cross-national project that provides a unique opportunity to evaluate the implementation of strength training in settings where it had previously not been applied. We report from the first 2 years of implementation using assessment data and surveys directed to frontline therapists responsible for the implementation. The strength training concept was progressively implemented in 24 elder care locations in Singapore including residential homes, day rehab/care centers, and senior activity centers. Each location was provided with training, support, gym equipment and technology solutions. It remained for individual sites to enroll elderly to the program, to perform assessments, and to direct the progressive strength training. Based on data from the first 2 years of implementation, improvements in lower body muscle strength were found in Leg Curl (ave 11.1–48.8%), Leg Extension (ave 10.2–24.0%) and Hip Abduction/Hip Adduction (ave 7.0–15.8%). Of the trained therapists, 95% strongly agreed or agreed to some extent that the implementation had been successful. The practice-based evidence from the project has demonstrated that it is feasible to implement progressive strength training in real life settings, using technology. While the implementation initially required handholding and support, the approach yielded consistent improvement rates in muscle strength comparable to results from randomized clinical trials (meta-analysis studies). Significant improvement rates in muscle strength were found in all three types of sites, demonstrating that gym training can be employed broadly in elder care. The Senior Activity Centers offer an interesting model for reaching seniors with preventive actions at an early stage. The data support a 3-month training as an effective intervention of introducing strength training in elder care settings, promoting healthy aging.

Ji, S, Donath, L, and Wahl, P. Effects of alternating unilateral vs. bilateral resistance training on sprint and endurance cycling performance in trained endurance athletes: A 3-armed, randomized, controlled, pilot trial. J Strength Cond Res 36(12): 3280-3289, 2022-Traditional preparatory resistance training for cyclists mainly relies on simultaneous bilateral movement patterns. This lack of movement specificity may impede transfer effects to specific aerobic and anaerobic requirements on the bike. Hence, this study investigated the effects of resistance training in alternating unilateral vs. simultaneous bilateral movement pattern on strength and anaerobic as well as aerobic cycling performance indices. Twenty-four trained triathletes and cyclists (age: 31.1 ± 8.1 years; V̇ o2 max: 57.6 ± 7.1 ml·min -1 ·kg -1 ) were randomly assigned to either an alternating unilateral (AUL), a simultaneous bilateral (BIL) training group or a control group (CON). Ten weeks of resistance training (4 × 4-10 repetition maximum) were completed by both training groups, although CON maintained their usual training regimen without resistance training. Maximal strength was tested during isometric leg extension, leg curl, and leg press in both unilateral and bilateral conditions. To compare the transfer effects of the training groups, determinants of cycling performance and time to exhaustion at 105% of the estimated anaerobic threshold were examined. Maximal leg strength notably increased in both training groups (BIL: ∼28%; AUL: ∼27%; p0.01) but not in CON (∼6%; p0.54). A significant improvement in cycling time trial performance was also observed in both training groups (AUL: 67%; BIL: 43%; p0.05) but not for CON (37%; p = 0.43). Bilateral group exhibited an improved cycling economy at submaximal intensities (∼8%; p0.05) but no changes occurred in AUL and CON (∼3%; p0.24). While sprint cycling performance decreased in CON (peak power: -6%; acceleration index: -15%; p0.05), improvement in favor of AUL was observed for acceleration abilities during maximal sprinting (20%; d = 0.5). Our pilot data underpin the importance of resistance training independent of its specific movement pattern both for improving the endurance cycling performance and maximal leg strength. Further research should corroborate our preliminary findings on whether sprint cycling benefits favorably from AUL resistance training.

Nuzzo, JL. Inconsistent use of resistance exercise names in research articles: a brief note. J Strength Cond Res 35(12): 3518–3520, 2021—Academic fields require standard nomenclature to communicate concepts effectively. Previous research has documented resistance training exercises are named inconsistently. This inconsistent use has been observed among fitness professionals and within resistance training textbooks. The purpose of the current note was to explore inconsistent use of resistance training exercise names in scientific articles. Keyword searches were performed in PubMed to identify articles that referred to 4 different resistance training exercises. The search was limited to titles and abstracts of articles published between 1960 and 2020. For exercise 1, “shoulder press,” “overhead press,” and “military press” were searched. For exercise 2, “arm curl,” “bicep curl,” and “biceps curl” were searched. For exercise 3, “hamstring curl,” “leg curl,” and “knee curl” were searched. For exercise 4, “calf raise” and “heel raise” were searched. For exercise 1, 114 articles included “shoulder press” in their title or abstract, 42 articles included “overhead press,” and 45 articles included “military press.” For exercise 2, 244 articles included “arm curl,” 37 articles included “bicep curl,” and 177 articles included “biceps curl.” For exercise 3, 24 articles included “hamstring curl,” 159 articles included “leg curl,” and 7 articles included “knee curl.” For exercise 4, 68 articles included “calf raise” and 154 articles included “heel raise.” The results are evidence of inconsistent use of resistance training exercise names in scientific articles. A possible solution to inconsistent use of exercise names in research articles, educational texts, and clinical practice is a system that includes a standard exercise naming pattern and guidelines for communicating exercise names.

The influence of exercise on brain function is an important topic, especially in persons with intellectual deficits. The aim of this study is to determine the effect of an acute bout of resistance training (RT) compared to assisted cycle therapy (ACT) and no training (NT) in adults with DS on cognitive function. Fourteen participants attended four sessions: a baseline assessment, an assisted cycling therapy (ACT) session, a resistance training (RT) session, and a session of no training (NT). In the RT session, the leg press, chest press, seated row, leg curl, shoulder press, and latissimus pulldown were performed. The ACT session consisted of 30 min of cycling and in NT session consisted of 20 min of board games. Inhibition was measured by the Erikson flanker task and cognitive planning was measured by the Tower of London test and both were administered prior to (pretest) and after each intervention (posttest). Our results showed that inhibition time improved more following RT and ACT than NT. There was also a significant difference between ACT and NT. For cognitive planning, improvements were seen following ACT and NT. In conclusion, an acute session of ACT demonstrated a significant trend towards improvements in executive functions in adults with DS which we interpreted using a model of neural changes and the cognitive stimulation hypothesis.

Background Hamstring injuries remain a major burden in football while the effective prevention exercise the Nordic Hamstring is poorly adopted, despite the added positive effects on performance. Better understanding of hamstring function during Nordic Hamstring compared to other exercises may provide better insight to the physiological adaptations of different types of hamstring curls. Purpose This cross-sectional study therefore aimed to compare the Nordic Hamstring curl with a conventional prone Leg Curl at different loads, and novel high velocity Hamstring Catches; in terms of peak normalized electromyographical activity (nEMG) and rate of electromyographic rise (RER) of Biceps Femoris long head, and angular velocity of the knee. Study design Cross-sectional study. Methods Out of 28 participants enrolled, the final sample included 23 recreationally active male participants who attended a session for determining RM (repetition maximum) to establish loading (8 and 16RM for Hamstring Catches, and 8, 16 and 24RM for Leg Curl) and to familiarize themselves with the three different exercises (Nordic Hamstring, Leg Curl and Hamstring Catch), and a testing session >4 days after during which EMG data were collected during 3 repetitions of each exercise performed in a random order. Results The Nordic Hamstring evoked higher RER (1091.8 nEMG/s) than Hamstring Catches (mean difference: 421 nEMG/s, p Conclusion The Nordic Hamstring displayed the highest level muscle activity and most explosive recruitment characteristics with early and high rate of electromyographic rise, compared to even high velocity exercises, thus providing a possible mechanism by which it may increase performance and reduce injuries. Levels of evidence 3 What is known about the subject Early phase force and muscle recruitment have been linked to both performance and hamstring-related inhibition and fatiguability. However, the potential for different hamstring exercises to elicit explosive recruitment is unknown. What this study adds to existing knowledge Early phase recruitment was higher and faster during the Nordic Hamstring exercise compared with conventional hamstring Leg Curl exercises with different loads and a high-velocity hamstring exercise. Clinical Relevance The surprisingly fast and explosive recruitment characteristics during the Nordic Hamstring exercise suggests the possibility that this exercise have the potential to improve the rate of force development and perhaps counter the effects of hamstring-related inhibition and fatigue.

In recent years, there has been a proliferation of technology and sport science utilized within an athlete’s physical activity and exercise. This study aims to assess the effectiveness of two strength and conditioning exercises, namely, a customized free-weight exercise and plate-loaded machine exercise, on the lower limb muscle activities of the amateur high jumpers. Six amateur high jumpers were divided into two groups, a customized free-weight group and plate-loaded machine group (control group) and performed exercises as instructed by the coach. The EMG signal of the Rectus Femoris and Bicep Femoris muscles were recorded during the exercises. Metronome was used to control the speed of the exercise and it was standardized for all subjects. The harmstring’s cable pull exercise (customized free-weight) triggered Bicep Femoris more compared to the leg curl exercise (plate-loaded exercise). Similarly, in the case of Rectus Femoris muscle, the front squat exercise (customized free-weight exercise) triggered higher muscular activities compared to the leg extension exercise (plate-loaded exercise). In conclusion, the customized free-weight exercise has indicated higher muscle activities compared to the plate-loaded exercise.

The aim of the current study was to investigate the relationships between limb muscular strength and bone mineral density (BMD) in a group of elderly subjects with low skeletal muscle mass index (SMI).55 elderly Lebanese subjects (35 women and 20 men) participated in the current study. Handgrip, one-repetition maximum (1-RM) dumbbell curl (1-RM biceps), 1-RM lying one arm triceps (1-RM triceps), 1-RM calf raise, 1-RM leg extension and 1-RM leg curl were evaluated using validated methods.In both genders, 1-RM biceps, 1-RM triceps, 1-RM leg extension and 1-RM leg curl were positively correlated to total hip BMD. The current study shows that limb muscular strength is positively correlated to hip BMD in elderly subjects with low SMI. This may have clinical implications in the field of osteoporosis prevention in elderly subjects with low SMI.

This study investigated the effects of hamstring training methods on the passive viscoelastic properties of hamstring and quadriceps muscles and the relationship of these properties to lower extremity power, hamstring flexibility, and agility. A total of forty healthy individuals were recruited for this study. Participants performed Nordic hamstring exercises (n = 14), hamstring curl exercises (n = 14), or received neuromuscular electrical stimulation (NMES; n = 13) for eight weeks. Measurements were taken both before and one week after the interventions of the viscoelastic properties of hamstring and quadriceps muscles, strength, flexibility, agility, and lower extremity power. Nordic hamstring exercises increased hamstring muscle elasticity while decreasing quadriceps and hamstring muscle stiffness; whereas leg curl exercises increased quadriceps and hamstring muscle stiffness while decreasing quadriceps muscle tone (P < .05). Both strengthening methods increased agility, hamstring flexibility, and vertical jump. NMES produced no noticeable effects. Eccentric and concentric training methods had inverse effects on both hamstring and quadriceps muscles' viscoelastic parameters, but had similar improvements on performance parameters. Since changes in viscoelastic parameters of muscle could affect musculotendinous systems' compliance, clinicians should consider viscoelastic properties over performance parameters, when prescribing concentric or eccentric exercises.

Obesity is known to be growing worldwide. The World Health Organization (WHO) reports that obesity has tripled since 1975. In 2016, 39% of adults over 18 years old were overweight, and 13% were obese. Obesity is mostly preventable by adopting lifestyle improvements, enhancing diet quality, and doing physical exercise. The workload of the physical exercises should be proportionate to the patient&rsquo, s capabilities. However, it must be considered that obese people are not used to training, they may not endure physical exertion and, even more critically, they could have some psychological impediments to the workouts. Physical exercises and equipment must, therefore, guarantee comfort and prevent situations in which the bariatric individual may feel inadequate. For these reasons, this study aims to design an innovative system to approach simple physical activities, like leg and arm exercises, to bariatric users to enable them to recover mobility and muscle tone gradually. The leading feature of this architecture is the design of hidden exercise mechanisms to overcome the psychological barriers of the users toward these kinds of machines. This paper proposes the initial design of the main sub-systems composing the rehabilitation machine, namely the leg curl and leg extension mechanism and its control architecture, the upper body exercises system, and a series of regulation mechanisms required to accommodate a wide range of users. The proposed functional design will then lead to the development of a prototype to validate the machine.

Nascimento de Oliveira Junior, G, de Freitas Rodrigues de Sousa, J, Augusto da Silva Carneiro, M, Martins, FM, Santagnello, SB, Campos Souza, MV, and Orsatti, FL. Resistance training volume enhances muscle hypertrophy, but not strength in postmenopausal women: a randomized controlled trial. J Strength Cond Res XX(X): 000-000, 2020-Among several possible resistance training (RT) variables to be manipulated, the training volume has been considered as a critical variable to maximize RT-induced hypertrophy. Many of the studies that compared one set of RT with 3 sets have failed to show a difference in muscle hypertrophy in older adults. However, it is not clear whether further increases in RT volume (i.e., 6 sets) would result in even greater RT-related hypertrophy than 3 sets in older adults. This study aimed to investigate whether higher-volume RT (HV-RT) maximizes gains in lean body mass and muscle strength (MS) when compared with lower-volume RT (LV-RT) in postmenopausal women (PW). Fifty-eight PW were randomized into 1 of the 3 groups: control group (CT, no exercise), HV-RT (6 sets per exercise), and LV-RT (3 sets per exercise). Volunteers took part in a supervised training program (leg press 45°, leg extension, leg curl and standing calf raises) and were assessed for leg lean mass (LLM; dual X-ray absorptiometry) and lower limb MS (leg press and leg extension; 1 repetition maximum [1RM]) before and after 12 weeks of RT. Both HV-RT and LV-RT groups increased (p < 0.05) LLM and MS when compared with the CT group. Higher increases in LLM gains were observed for the HV-RT group when compared with the LV-RT group (6.1 and 2.3%, p < 0.001). Both HV-RT and LV-RT groups similarly increased 1RM in the leg press and leg extension. Thus, there seems to be a dose-response relationship between RT volume and muscle hypertrophy, but not for MS gains in PW.

Background: Oral gamma-aminobutyric acid (GABA) supplementation increases growth hormone (GH) serum levels and protein synthesis. Therefore, post-exercise supplementation using GABA and protein may help enhance training-induced muscle hypertrophy. We evaluated whether GABA with whey protein enhanced muscular hypertrophy in men after progressive resistance training. Methods: Twenty-one healthy men (26 - 48 years) were randomized to receive whey protein (WP; 10 g) or whey protein + GABA (WP + GABA; 10 g + 100 mg) daily for 12 weeks. Both groups performed resistance training twice per week (three sets of 12 repetitions at 60% of maximal strength; leg press, leg extension, leg curl, chest press, and pull down). Body composition was assessed using dual-energy X-ray absorptiometry. Results: In the WP + GABA group, resting plasma GH concentrations were significantly elevated at 4 and 8 weeks, compared to baseline. However, resting plasma GH concentrations in the WP group were only significantly elevated at 8 weeks. After 12 weeks, the WP + GABA group exhibited significantly greater increase in whole body fat-free mass than the WP group. Conclusions: The GABA and whey protein combination was more effective for increasing whole body fat-free mass; daily GABA supplementation may help enhance exercise-induced muscle hypertrophy. J Clin Med Res. 2019;11(6):428-434 doi: https://doi.org/10.14740/jocmr3817

Hirose, N and Tsuruike, M. Differences in the electromyographic activity of the hamstring, gluteus maximus, and erector spinae muscles in a variety of kinetic changes. J Strength Cond Res 32(12): 3366-3372, 2018-This study aimed to clarify the differences in the electromyographic (EMG) activity of the semitendinosus (ST), semimembranosus (SM), biceps femoris long head (BFl), gluteus maximus (GM), and erector spinae (ES) muscles during leg curl and bridge exercises across different knee angles and isometric contraction outputs. Sixteen male volunteers participated in this study. The EMG of all targeted muscles was measured at 20 and 40% of the maximal voluntary isometric contraction (MVIC) in the leg curl and during bilateral and unilateral bridge exercises. The knee flexion angle was randomly set at 30, 60, 90, and 120° during each of the exercises. The obtained data were normalized by the MVIC of the corresponding muscle, and each of the normalized values was compared with that of the ST. The EMG activity of the ST was significantly greater at 120° of knee flexion than that of 30 and 60° of knee flexion during leg curl regardless of intensity (p < 0.05), in contrast with that of the SM and BFl. However, bridge exercises diminished this inverse relationship. The ES activity changed similarly to that of the hamstrings, and no difference was observed in the activity of the GM regardless of different knee angles during bridge exercise(s). The strength and conditioning professionals should alter the knee joint angle and load during bridge and leg curl exercises according to which hamstring muscle they want to strengthen because ST, SM, and BFl EMG activity varies depending on the intensity and knee angles during these exercises.

Purpose: Maternal obesity can unfavorably influence offspring body composition, muscle strength, and possibly muscle's adaptability to training, but the human studies are scarce. Therefore, we aimed to investigate the effect of maternal obesity on offspring muscle strength responses to resistance training intervention in elderly frail women. Materials/methods: Recruited participants were elderly frail women offspring of lean/normal weight mothers (n = 19, mean body mass index (BMI): 22.8 kg/m2, range: 19.9-24.5) or overweight/obese mothers (n = 16, mean BMI: 29.7 kg/m2, range: 28.2-34.2). Information on maternal BMI immediately prior to delivery was collected from the birth registers. All women participated in a 4-month supervised progressive resistance training intervention three times a week for 60 min. Predicted 1-RM of abdominal crunch, hip abduction, leg curl, leg press, seated row, and total strength were measured at baseline and after each month of training. Results: According to rANOVA, strength increased significantly in both groups (p for time 0.072). On average, muscle strength of the women offspring of overweight/obese mothers tended to be lower than in women offspring of lean/normal weight mothers, but the only significant difference was found in leg curl (p = 0.006). No significant differences between the groups were found in relative strength changes from baseline to 4-months. Conclusions: Muscle strength response to supervised resistance training is not modulated by maternal adiposity in late pregnancy in elderly frail female offspring.

The aims of this pilot study were to verify which muscle strength tests better explain bone mineral content (BMC) of the femoral neck and lumbar spine and to develop predictive equations to estimate femoral neck and lumbar spine BMC. Twenty-nine subjects aged 56–76 years old (12 women and 17 men) participated in the study. Femoral neck and lumbar spine BMC was evaluated by Dual X-ray absorptiometry (DXA). Muscle strength measurements included maximal isometric voluntary contractions of knee extensors and flexors, vertical jump, 5-repetition maximum of the leg press (5-RM LP ) and seated leg curl (5-RM LC ), and handgrip strength. Women presented a moderate to strong correlation between femoral neck BMC and 5-RM LP (r = 0.819), 5-RM LC (r = 0.879), knee extensors peak torque (r = 0.699), and handgrip strength (r = 0.663), as well as between lumbar spine BMC and the 5-RM LP test (r = 0.845) and manual grip strength (r = 0.699). For females, the 5-RM LP and 5-RM LC tests most fully explained femoral neck BMC (R 2 = 0.859) and the 5-RM LP test and body mass explained lumbar spine density (R 2 = 0.757) for females. Men did not present correlations between BMC and strength variables. For females, the 5-RM LP and 5-RM LC variables explained the variations of femoral neck BMC, while 5-RM LP and body mass explained lumbar spine BMC. Future studies should evaluate a larger sample size and prioritize the strength tests with a greater predictive capacity.

Farrell III, JW, Lantis, DJ, Ade, CJ, Cantrell, GS, and Larson, RD. Aerobic exercise supplemented with muscular endurance training improves onset of blood lactate accumulation. J Strength Cond Res 32(5): 1376-1382, 2018-Studies have shown that when aerobic exercise is supplemented with muscular endurance training metabolic adaptions occur that result in the delay of the onset of blood lactate accumulation (OBLA). However, previous studies have not explored any submaximal cardiorespiratory adaptations that may result from this training protocol. The aim of the current investigation was to evaluate the effect of supplementing an aerobic exercise training program with a muscular endurance training program on various cardiorespiratory and metabolic measurements. Fourteen aerobically active men performed an incremental exercise test to determine the OBLA, gas exchange threshold (GET), and maximal oxygen uptake (V[Combining Dot Above]O2max). Maximal strength was measured using 1 repetition maximum (1RM) for leg press (LP), leg curl (LC), and leg extension (LE). Eight subjects supplemented their aerobic activity (experimental [EX] group) with 8 weeks of muscular endurance training, while 6 continued their regular aerobic activity (control [CON] group). No significant group differences were observed for all pretraining variables. After 8 weeks of training, no significant differences in body mass, GET, and V[Combining Dot Above]O2max were observed for either group. However, the EX group showed a significant improvement for both absolute and relative V[Combining Dot Above]O2 at OBLA compared with the CON group. Leg curl and LE 1RM assessments for the EX group showed a significant improvement compared with CON group. Muscular endurance training did not improve GET and V[Combining Dot Above]O2max, but significantly increased V[Combining Dot Above]O2 at OBLA, LP, and LC. These findings suggest that this training protocol maybe useful in the development of submaximal aerobic performance and leg strength for endurance athletes.

Introduction: Strength training is able to stimulate bone tissue metabolism by increasing mechanical stress on the skeletal system. However, the direct relationship is not yet well established among younger women, since it is necessary to describe which strength enhancement level is able to produce effective changes in bone integrity. Objectives: This study analyzed the influence of muscle strength on bone mineral content (BMC) and bone mineral density (BMD) among female college students. Methods: Fifteen women (24.9 ± 7.2 years) were assessed for regional and whole-body composition by dual-energy X-ray absorptiometry (DXA). The one-repetition maximum (1-RM) tests were assessed on flat bench press (BP), lat pulldown (LPD), leg curl (LC), knee extension (KE), and 45 degree leg press (45LP). Linear regression analyzed the relationships of BMC/BMD with regional composition and 1-RM test values. Measures of dispersion and error (R2 adj and SEE) were tested, defining a p-value of 0.05. Results: The mean value of whole-body BMC was 1925.6 ± 240.4 g and the BMD was 1.03 ± 0.07 g/cm2. Lean mass (LM) was related to BMC (R2 adj = 0.86, p

The purpose of this study was to examine the effects of start of season maximal strengthtraining applied to elite athletes on body composition and some strength parameters of theathletes. Material and Method: 17 elite wrestlers at national team level with an average age of18 who were staying at a camp and who had the same dietary conditions participated in thestudy. Strength trainings were made three days a week (Monday -Wednesday-Friday) beforenoon. The training program applied to athletes was applied as 75% intensity and 8 repetitionsin the first set, 80% intensity and 6 repetitions in the second set, 85% intensity and 4repetitions in the third set, 90% intensity and 3 repetitions in the fourth set, and 95-100%intensity and 2 repetitions in the fifth set. The training program included shoulder press,bench press, lat pull, squat, butterfly, barbell curl, jerk, and leg curl moves. The study lastedfor 8 weeks. Specified tests were taken starting from the first training and they were takenbefore the last trainings of weeks 4 and 8. Body composition was measured with TANITATBF 300A make device (BMI, Fat, Fat mass, FFM, TBW). As for strength tests, back and legmeasurements were made with Baseline Back Leg Chest DAWOB660 make leg and backdynamometer, while handgrip strength was measured with Takei Hand Dynamometer(Handgrip). Results: According to the results of the study, participants’ body weight (BW)values were not found to differ significantly based on the period of training (p>0.05).Similarly, no significant differences were found in BMI values depending on the period oftraining (p>0.05). In addition, significant differences were found in total body water (Tbw),fat, and fat mass values depending on the period of training (p

Introduo: O mtodo pareado agonista-antagonista (PAA) consiste em estimular previamente a musculatura antagonista do grupo muscular que se deseja otimizar, aumentando a ativao neural e fora dos msculos agonistas. Objetivo: Comparar o mtodo tradicional vs PAA sobre o trabalho total (TT) e volume de treinamento (VT) no exerccio cadeira extensora (CE). Mtodos: Doze mulheres treinadas realizaram dois protocolos experimentais randomizados: mtodo tradicional - quatro sries da CE at a falha concntrica; mtodo PAA: quatro sries de mesa flexora (MF) + CE at a falha concntrica. Foi dado um intervalo de 30 segundos entre os dois exerccios. Resultados: Pde-se observar diferena significativa tanto no TT como VT, para o mtodo PAA quando comparado ao tradicional. Concluso: Sugere-se assim que o mtodo PAA apresenta-se como melhor estratgia para otimizao do desempenho de repeties mximas se comparado ao mtodo tradicional, alm de apresentar possibilidade de reduo no tempo despendido para o treinamento.

Power training has become a common exercise intervention for improving muscle strength, power, and physical function while reducing injury risk. Few studies, however, have evaluated acute load changes on power output during traditional resistance training protocols. Therefore, the aim of this study was to quantify the effects of different loading patterns on power output during a single session of circuit resistance training (CRT). Nine male (age = 19.4 ± 0.9 years) and 11 female participants (age = 20.6 ± 1.6 years) completed 3 CRT protocols during separate testing sessions using 7 pneumatic exercises. Protocols included heavy load explosive contraction (HLEC: 80% one repetition maximum [1RM], maximum speed concentric-2 seconds eccentric), heavy load controlled contraction (HLCC: 80% 1RM, 2 seconds concentric-2 seconds eccentric), and moderate load explosive contraction (MLEC: 50% 1RM, maximum speed concentric-2 seconds eccentric). Protocols were assigned randomly using a counterbalanced design. Power for each repetition and set were determined using computerized software interfaced with each machine. Blood lactate was measured at rest and immediately postexercise. For male and female participants, average power was significantly greater during all exercises for HLEC and MLEC than HLCC. Average power was greatest during the HLEC for leg press (LP), hip adduction (ADD), and hip abduction (ABD) (p ≤ 0.05), whereas male participants alone produced their greatest power during HLEC for leg curl (LC) (p < 0.001). For male and female participants, significantly greater power was detected by set for LP, lat pull-down (LAT), ADD, LC, and ABD for the MLEC protocol (p < 0.02) and for LP, LAT, CP, and LC for the HLEC protocol (p < 0.03). A condition × sex interaction was seen for blood lactate changes ((Equation is included in full-text article.)= 0.249; p = 0.024), with female participants producing a significantly greater change for MLEC than HLEC (Mdiff = 1.61 ± 0.35 mmol·L; p = 0.011), whereas male participants showed no significant differences among conditions. Performing a CRT protocol using explosive training patterns, especially at high loads for lower-body exercises and moderate loads for upper-body exercises, produces significantly higher power than controlled speed training in most exercises. These results provide exercisers, personal trainers, and strength coaches with information that can assist in the design of training protocols to maximize power output during CRT.

Background: Previous investigations have shown that muscular endurance resistance training (MERT) is conducive in improving the onset of blood lactate accumulation (OBLA). However, the metabolic response and time course for adaption is still unclear. Objective: The aims of the current study were to evaluate and track the metabolic response to an individual session of MERT as well as to assess performance adaptations of supplementing an aerobic exercise training program with four weeks of MERT. Methods: Seventeen aerobically active men were randomly assigned to either the experimental (EX) or control group (CON), 9 EX and 8 CON. Baseline measures included a graded exercise test (GXT) and 1-repetition maximum (1RM) testing for leg press (LP), leg curl (LC), and leg extension (LE). CON continued their regular aerobic activity while the EX supplemented their regular aerobic exercise with 4 weeks of MERT. Results: No significant group differences were observed for all pre-training variables. Following four weeks of training no significant differences in cardiorespiratory or metabolic variables were observed for either group. However, significant improvements in LC and LE 1-RM were observed in EX compared to CON. Substantial accumulations in blood lactate were observed following each MERT session. Conclusion: Four weeks of MERT did not improve cardiorespiratory or metabolic variables, but did significantly improve LC and LE. MERT was also observed to induce a blood lactate response similar to that of HIIT. These findings suggest greater than four weeks is need to see metabolic adaptations conducive for improved aerobic performance using MERT.

The aim of this study was to analyse the effects of a combined strength-training programme (full-back squat, YoYoTM leg curl, plyometrics and sled towing exercises) on performance in elite young soccer players and to examine the effects when this training programme was performed one or two days per week. Thirty-six male soccer players (U-17 to U-19) were recruited and assigned to experimental groups (EXP1: 1 s w−1; EXP2: 2 s w−1) or a control group (CON). Performance was assessed through a countermovement jump (CMJ) test (relative peak power [CMJPP] and CMJ height [CMJH]), a 20-m linear sprint test with split-times at 10-m, and a change of direction test (V-cut test) 1 week before starting the training programme and also 1 week after performing such training programme. Within-group analysis showed substantial improvements in CMJ variables (ES: 0.39–0.81) and COD (ES: 0.70 and 0.76) in EXP1 and EXP2, while EXP2 also showed substantial enhancements in all linear sprinting tests (ES: 0.43–0.52). Betw...

Objective The purpose of this study was to investigate the effects of different intervals between static stretching for hip adductor, quadriceps and hamstring muscles and resistance training in repetition performance. Method Twenty-two trained men were submitted to the 10 repetition maximum test and retest for leg extension, leg curl and hip adduction exercises. Three protocols were conducted in a randomized design – PWI: resistance training immediately after static stretching; P15: fifteen-minute rest interval between static stretching and resistance training; P30: thirty-minute rest interval between static stretching and resistance training. Results The total number of repetition [(sets * repetitions) + exercises] performed under P30 (84.55 ± 1.68) was significantly higher than P15 (79.73 ± 1.89) and PWI (68.09 ± 2.03), respectively. Significant differences were also found between P15 and P30. Conclusions Therefore, 30-minute interval between static stretching and resistance exercises was needed to achieve greater repetition performance. Thus, static stretching for lower limbs may be avoided before a resistance training session.

The aim of this study was to examine the influence of caffeine supplementation (4.5 mg⋅kg−1) on lower body resistance training (RT) performance preceded with and without an acute bout of endurance exercise. In a double-blinded crossover study, 10 moderately active males (20.6±2.1 yo) carried out six exercise sessions (2 x 1RM sessions; 2 x resistance sessions; 2 concurrent sessions). Resistance exercise sessions (CAF+RES and PLA+RES) were carried out with 4 maximum sets of leg press, leg extension and leg curl to volitional fatigue at 65% of 1RM for each exercise with 1 min inter-set and inter-session rest interval. Sessions consisted on 4 maximum sets to volitional fatigue at 65% of 1RM for each exercise with 1 min of rest interval between sets and exercises. Concurrent training sessions (CAF+CON and PLA+CON) were identical but were preceded by 30 min of continuous treadmill running at 75-85% HRmax. Physical performance showed a significant main effect for treatment (p < 0.0001), protocol (p < 0.02), exercises (p < 0.0001) and sets (p < 0.0001). Physical performance during RES was reduced after endurance exercise, indicating a cumulative effect of CON. Caffeine supplementation blunted this cumulative effect. We conclude that caffeine supplementation could be used to improve the RT performance when it is done immediately after an aerobic training.

Lantis, DJ, Farrell, JW, III, Cantrell, GS, and Larson, RD. Eight weeks of high volume resistance training improves onset of blood lactate in trained individuals. J Strength Cond Res 31(8): 2176-2182, 2017-The purpose of this study was to determine if onset of blood lactate (OBLA) using the fixed at 4 mmol·L method could be delayed by supplementing high-volume resistance training (HVRT) to existing endurance training programs. There were 20 male subjects who participated in the study; 11 experimental (EX) (22.8 ± 4.6 years) and 9 controls (CON) (23.2 ± 5.8 years). An incremental cycling test was performed to determine maximal oxygen uptake, OBLA, maximum power, and time to exhaustion. Additionally, strength of the leg press (LP), leg curl (LC), and leg extension (LE) was assessed in both groups. Participants continued their ongoing endurance training, whereas the EX group supplemented their training with HVRT twice weekly for 8 weeks, performing 4 sets of 15 repetitions of LP, LC, and LE. Change score (post-pre) analysis was measured, using t-tests to compare the differences between groups, to eliminate outside variables that may have affected testing performance. Significance was set at p ≤ 0.05. No significant group differences in baseline measures were observed. A significant difference was observed for OBLA at 4 mmol·L (EX: 18.17 ± 15.36 W and CON: -3.52 ± 20.13 W, p < 0.02). A significant difference was observed for LP (EX: 39.09 ± 25.87 kg and CON: 4.22 ± 34.65 kg, p < 0.02) and LC (EX: 22.84 ± 8.7 kg and CON: -1.47 ± 8.2 kg, p < 0.01). Supplementing HVRT in endurance-trained individuals delayed OBLA at 4 mmol·L and improved leg strength. The HVRT used in the current study may be a useful training style for endurance-trained individuals.

To investigate the effects of acute aerobic and resistance exercise on the arterial stiffness and the left ventricular systolic time interval(STI), high school students(16.4±.8 yrs, n=15) were tested at resting state, immediately after exercise, recovery 1hr, and 2hr. Experiments were performed in 3 conditions; control without any handling, aerobic exercise with track running at 80% HRR, and resistance exercise with maximal repetitions at 60% RM on bench press, arm curl, leg press and leg curl. Data were analyzed by repeated two-way ANOVA on time and exercise type. As results, ABPI, baPWV and AIx, that were arterial stiffness variables, were tend to decrease at immediately after aerobic and resistance exercise, but these variables were recovered and increased than the resting values during recovery 1hr and 2hr. The patterns of STI, LVET and PEP/LVET, that were left cardiac contractility variables, were similar with those of arterial stiffness variables during recovery periods after aerobic and resistance exercise. In conclusion, the arterial stiffness was decreased at immediately after aerobic and resistance exercise, but they were increased during recovery. These changes of arterial stiffness variables seemed to be independent with left cardiac contractility variables.

Digital, Delextrat, A, Bateman, J, Ross, C, Harman, J, Davis, L, Vanrenterghem, J, and Cohen, DD. Changes in torque-angle profiles of the hamstrings and hamstrings-to-quadriceps ratio after two hamstring strengthening exercise interventions in female hockey players. J Strength Cond Res 34(2): 396–405, 2020—The aim of this study was to compare the effects of 2 hamstring strengthening interventions (Nordic hamstrings [NHE] vs. eccentric leg curl [ELC]) on the hamstring torque-angle profiles and functional hamstrings-to-quadriceps ratio (Hecc:Qcon) in female hockey players. Female university-level players were randomly allocated to an NHE group (n = 9, 19.7 ± 1.4 years; 168.4 ± 4.4 cm; 66.2 ± 7.2 kg, 26.0 ± 4.4%), an ELC group (n = 8, 19.5 ± 1.0 years; 168.1 ± 3.4 cm; 66.7 ± 4.5 kg, 24.8 ± 3.5%), or a control (C) group (n = 8, 19.6 ± 1.4 years; 169.9 ± 7.5 cm; 70.7 ± 13.0 kg, 25.9 ± 5.2%). They performed baseline isokinetic concentric strength tests of the quadriceps (Qcon) and eccentric strength of the hamstrings (Hecc) at 120°·s−1, followed by a 6-week intervention with exercises (NHE or ELC) performed 3 times weekly, before post-tests. Analyses of variance with repeated measures were used to assess the effects of knee position angle (from 90° of knee flexion to 10° close to extension), group, and time on Qcon, Hecc, and Hecc:Qcon. There were no interactions between independent variables. Significant increases in Hecc and Hecc:Qcon were shown after NHE (+29.9 and +27.8%) and ELC (+30.5 and +38.3%) in the nondominant leg only. Furthermore, significant shifts in the hamstring eccentric angle of peak torque toward a longer muscle length were shown in both legs (14.3–28.6%). These findings suggest that NHE and ELC both resulted in significant improvements in peak and muscle-length–specific neuromuscular risk factors in the nondominant (ND) limb, thereby reducing interlimb peak strength asymmetries. Strength and conditioning specialists could therefore use both the NHE and ELC exercises in female hockey players., Ciencias Médicas y de la Salud

The purpose of this study was to explore the effects of slow-speed resistance training with low intensity (SRT) on muscle power output in elite futsal players with respect to traditional resistance training. The authors hypothesized that the muscle deoxygenation during SRT causes early recruitment of fast twitch fibers that would positively affect strength and power performance. Thirty male elite futsal players were recruited and randomly assigned either to SRT group or to traditional resistance training (TRT) group. All players underwent an 8-weeks experimental protocol consisting of 2 training sessions per week at both leg curl and leg extension machines. In the SRT, players lifted 50% of one maximum repetition (1RM) involving 3 s for eccentric and concentric actions. In the TRT, players lifted 80% of 1RM involving 1 s for eccentric and concentric actions. All players were tested twice (pre and post) for sprint and jump performances, maximal isometric voluntary contraction (MVC) and maximal isokinetic peak torque (Peak TQ) and total work (TW) at 60 and 120°/s (on knee extensors and flexors). The two groups presented remarkable differences in the within-group changes for all the variables. SRT exhibited greater improvements in both Peak TQ and TW for knee extensors and flexors at 120°/s. Conversely, TRT showed greater improvements in MVC, and in both Peak TQ and TW for knee extensors and flexors at 60°/s, except for Peak TQ of the knee extensors, where no significant difference was found between TRT and SRT. Countermovement jump showed a decrease in eccentric time and an increase in concentric force in SRT group. SRT and TRT resulted effective to enhance the strength performance indices during the 8-weeks experimental protocol. Peak torque at 120°/s explained more of the contractile characteristic effects of SRT training than MVC, suggesting that slow-speed training can cause fast twitch fibers hypertrophy in elite athletes. Since slow-speed training is supposed to produce a decreased exercise-induced muscle damage, SRT method is a suitable option in strength training for futsal and team sports.

Purpose: The Nordic hamstring exercise (NHE) has been shown to considerably reduce hamstring injuries among soccer players. However, as the load in the NHE is the person’s own bodyweight, it is a very heavy exercise and difficult to individualize. The flywheel inertial leg curl (FLC) could be an alternative since the eccentric overload is based on the amount of work produced in the concentric movement. Therefore, the primary aim of this study was to compare the activation in the hamstrings at long muscle lengths in the NHE and the FLC in amateur soccer players. Methods: Fifteen male amateur soccer players performed 5 repetitions in each exercise in a randomized and counterbalanced order. The concentric and eccentric movements were divided into lower and upper phases. Surface EMG was measured distally, proximally, and in the middle, at both muscles. Results: In the lower phase in the eccentric movement, there were no significant differences between the 2 exercises (P = .101–.826). In the lower concentric movement, the FLC led to higher activation in all parts of both the biceps femoris (31%–52%, P P = .001–.023). Conclusion: Both exercises activated the hamstrings similarly at long muscle lengths during eccentric contractions (Nordic hamstring, nonsignificantly higher). However, when performing concentric contractions, the FLC induced higher activations. Therefore, the FLC could be a useful alternative to the NHE and particularly suitable for weaker athletes before progressing to NHE.

Background: Whole-body electromyostimulation (WB-EMS) gained increasing interest in sports within recent years. However, few intervention studies have examined the effects of WB-EMS on trained subjects in comparison to conventional strength training. Objective: The aim of the present mini-meta-analysis of 5 recently conducted and published randomized controlled WB-EMS trails of our work group was to evaluate potentially favorable effects of WB-EMS in comparison to conventional strength training. Methods: We included parameter of selected leg muscle's strength and power as well as sprint and jump performance. All subjects were moderately trained athletes [>2 training sessions/week, >2 years of experience in strength training; experimental group (n = 58): 21.5 ± 3.3 y; 178 ± 8 cm; 74.0 ± 11 kg; control group (n = 54): 21.0 ± 2.3 y; 179.0 ± 9 cm; 72.6 ± 10 kg]. The following WB-EMS protocols were applied to the experimental group (EG): 2 WB-EMS sessions/week, bipolar current superimposed to dynamic exercises, 85 Hz, 350 μs, 70% of the individual pain threshold amperage. The control groups (CG) underwent the same training protocols without WB-EMS, but with external resistance. Results: Five extremely homogenous studies (all studies revealed an I2 = 0%) with 112 subjects in total were analyzed with respect to lower limb strength and power in leg curl, leg extension and leg press machines, sprint—and jump performance. Negligible effects in favor of WB-EMS were found for Fmax of leg muscle groups [SMD: 0.11 (90% CI: −0.08, 0.33), p = 0.73, I2 = 0%] and for CMJ [SMD: 0.01 (90% CI: −0.34, 0.33), p = 0.81, I2 = 0%]. Small effects, were found for linear sprint [SMD: 0.22 (90% CI: −0.15, 0.60), p = 0.77, I2 = 0%] in favor of the EMS-group compared to CON. Conclusion: We conclude that WB-EMS is a feasible complementary training stimulus for performance enhancement. However, additional effects on strength and power indices seem to be limited and sprint and jump-performance appear to be benefiting only slightly. Longer training periods and more frequent application times and a slightly larger stimulus could be investigated in larger samples to further elucidate beneficial effects of WB-EMS on performance parameters in athletes.

Background The improvement of strength and athletic performance during a competitive season in elite soccer players is a demanding task for the coach. Aims As whole-body electrostimulation (WB-EMS) training provides a time efficient stimulation potentially capable in exerting skeletal muscle adaptations we aimed to test this approach over 7 weeks in trained male soccer players during a competitive season. Hypothesis We hypothesized that a superimposed WB-EMS will increase maximal strength and type I and type II myofiber hypertrophy. Methods Twenty-eight male field soccer players were assigned in either a WB-EMS group (EG, n = 10), a training group (TG, n = 10), or a control group (CG, n = 8). The regular soccer training consists of two to four sessions and one match per week. In concurrent, the EG performed 3 × 10 squat jumps superimposed with WB-EMS twice per week, TG performed 3 × 10 squat jumps without EMS twice per week, and the CG only performed the regular soccer training. Muscle biopsies were collected and strength tests were performed under resting conditions before (Baseline) and after the intervention period (Posttest). Muscle biopsies were analyzed via western blotting and immunohistochemistry for skeletal muscle adaptive responses. To determine the effect of the training interventions a 2 × 3 (time ∗ group) mixed ANOVA with repeated measures was conducted. Results Maximal strength in leg press (p = 0.009) and leg curl (p = 0.026) was significantly increased in EG along with a small but significant increase in type II myofiber diameter (p = 0.023). All of these adaptations were not observed in TG and CG. Conclusion WB-EMS can serve as a time efficient training method to augment strength capacities and type II fiber myofiber growth in soccer players when combined with specific resistance training. This combination may therefore be a promising training modification compared to traditional strength training for performance enhancement.