Leg Curl Research Articles

Rehabilitation Machine for Bariatric Individuals

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’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.

Influence of exercise order on the number of repetitions in untrained teenagers.

Introduction: Prescription of resistance training (RT) is increasing among teenagers, requiring further studies to investigate the effects on this population. Objective: To examine the different orders on exercises sequence and its influence on the number of repetitions in teenager. Methods: Participated in the study 12 voluntarily male teenagers (14.91 ± 0.79 years, 1.69 ± 8.61 cm, 62.24 ± 7.26 kg) without experience in RT. After 48 hours of the last session of 10 repetitions maximum (10RM) test, subjects performed one of the four sequences of exercises in a counterbalanced crossover design. Four different sequences were also performed with a interval of 48 hours. All sequences were three sets of each exercise with 10RM load, with two-minute intervals between sets and exercises. The order of exercises was the sequence 1: bench press (BP), pulldown (PD), machine shoulder press (SP), biceps curl (BC) and triceps (TR); Sequence 2: TR, BC, SP, PD and BP; the sequence 3: Leg press (LP), leg extension (LE) and leg curl (LC); Sequence 4: LC, LE and LP. Results: Significant differences were observed (p <0.05) in the total number of repetitions for the BP exercises, SP, BC and TR for the sequence of the upper limbs and for the lower limbs and the LP and LE exercises. Conclusion: The results suggest that the performance of the average number of repetitions for sessions conducted with RT intensity of 10RM in teenagers was influenced by the different kind of exercises in both upper and lower limbs.

Comparison Of The Effects Of Two Different Resistance Training Programs On Strength In Older Males

PURPOSE: The purpose of this study was to compare the effects of 8 weeks of blood flow restriction (BFR) training and traditional endurance resistance training on isotonic, isokinetic, isometric strength in older males. METHODS: A total of 17 males (57.0 yr ± 4.6 yr) completed the study. Subjects were randomly assigned to two training groups: blood flow restriction (BFR; n= 9) or endurance resistance training (END; n = 8). Prior to exercise training, baselines measurements were recorded, including height, weight, one repetition maximum (1RM), and unilateral knee extension testing to determine maximal voluntary contraction (MVC) and isokinetic torque at 60°/sec and 180°/sec. Training was held three times a week in a training room under laboratory settings and under the supervision of an experienced and certified strength and conditioning specialist, who ensured that subjects used proper exercise form and provided verbal encouragement. The following machine-based exercises were performed: Leg press, leg extension, leg curl, chest press, and shoulder press. Following a warm-up consisting of a 5-minute walk or jog, the BFR group performed 4 sets of 20 repetitions of the 5 exercises at 20-30% 1RM, while the END group performed 4 sets of 15 repetitions of the 5 exercises at 40-65% 1RM, with 30-60 seconds of rest between exercises. Cuffs were placed at the upper most portion of the limbs. Initial cuff tightness was kept between 30 and 40 mmHg for upper and lower limbs, and final pressure of the cuffs was between 140 to 160 mmHg for upper body 160 to 200 mmHg for lower body. BFR group rested 3-5 minutes between upper and lower body exercises. Following completion of the 8-week training, the measurements at baseline were re-recorded. RESULTS: One-way ANOVA resulted in no difference between groups at baseline. Time main effects were seen in 1RM (p ≤0.05), isokinetic torque at 60°/sec (p ≤0.05) and 80°/sec (p ≤0.05), and MVC (p ≤0.05) tests. CONCLUSION: The BFR and END training protocols resulted in similar results on improving strength after 8 weeks of resistance training. It could be speculated that even though half the weight was lifted during the BFR sessions compared to the END sessions, the BFR-related local and systemic changes elicited similar improvements in isotonic, isokinetic, and isometric strength in older males.

Effects Of An 8-week Nordic Hamstring Vs. Isokinetic Eccentric Training Intervention On Biceps Femoris Muscle-tendon Interactions

Resistance eccentric training triggers adaptations in both active and passive elements of the muscle tendon unit (MTU). Previous research highlight the buffering role that tendinous tissues may play to mitigate muscle strain and to optimize operating fascicle lengths. However, the effects of eccentric training on the muscle-tendon interactions of the biceps femoris remain unexplored. PURPOSE: To evaluate the effects of eccentric training on torque and muscle-tendon interactions of the biceps femoris muscle during lengthening contractions. METHODS: Eighteen participants completed an 8-wk standardized eccentric training intervention comprising 15 sessions of Nordic Hamstring (NH) or isokinetic leg curl (IK; n=10) exercise. Pre and post training, torque and fascicle, tendinous tissue and MTU length of the biceps femoris muscle were measured during maximal 70° lengthening knee extensions at 60°.s-1. One sample t-test statistical parametric mapping (SPM) analyses were performed to evaluate fascicle and tendon behaviour during the contractions. Training effects were evaluated with two-way repeated measures ANOVA and paired t-test SPM. RESULTS: Both groups increased torque from 38% to 100% of the contraction duration, with greater improvements in IK from 78.5 to 100% (p < 0.001). The contribution of tendinous tissue to MTU length changes slightly increased only in IK at the last 2% of the contraction (p = 0.04). Despite opposite trend changes in NH, no training effects on fascicle or tendon behavior occurred. The tendinous tissues contribution to MTU lengthening was greater than fascicles up to 75% of the contraction. The fascicles contribution progressively augmented at the end of the contraction (p < 0.05). CONCLUSION: We provide novel findings on the muscle-tendon interactions of the biceps femoris muscle during lengthening contractions. A 15-session eccentric training program comprising NH or IK exercise does not seem to affect muscle-tendon interactions.

Comparison of Strength Values of Professional Footballers According to Their Positions before Football Season

The purpose of the present study was to compare the strength values of professional footballers according to their positions before the football season. The study group consisted of 27 professional footballers of Şanlıurfaspor Football Club in the 2nd League of Turkey. The mean height of the Study Group was 180.92±6.18 (cm), mean body weight was 80.18±1.5 (kg), and the mean age was 26.40±4.4 (years). The inclusion criteria for the study was being volunteers, and the necessary permissions were obtained from the players, club managers and coaches. The Precor-brand device was used to measure the differences of strengths according to the positions of the footballers. “1 RM” measurements were made from shoulder press, latt pully, leg curl, leg extension, and leg press machines in the footballers. The SPSS 24.00 Program was used in the statistical analysis of the study data. The descriptive statistics were given as mean, standard deviation, and minimum and maximum values. The normality test of the data was analyzed with the Shapiro-Wilk Test. One-Way Anova Test was used to identify the differences between the players and the positions. The significance level was determined as 0.05. According to the results obtained in the study, no significant differences were detected in strength values between goalkeeper, defender, midfielder, and striker positions (p &gt; 0.05). As a result, among the biomotoric properties, strength is important, and quite necessary for a footballer to perform at a high level. These values obtained from 2nd League football players are important for being taken as reference values, and it can be argued that these values obtained in the pre-season prepared the basis for the lack of qualitative differences. In future studies, data that will be obtained from different league levels and training stages will lead to research being considered differently.

Resistance Training Volume Enhances Muscle Hypertrophy, but Not Strength in Postmenopausal Women: A Randomized Controlled Trial.

Nascimento de Oliveira Júnior, 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 36(5): 1216-1221, 2022-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.

Improvements in muscle strength, power, and size and self-reported fatigue as mediators of the effect of resistance exercise on physical performance breast cancer survivor women: a randomized controlled trial.

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 12weeks. 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 12weeks, 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 Effects of Resistance Exercise Selection on Muscle Size and Strength in Trained Women.

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<0.01). However, MJ and MJ+SJ groups obtained greater gains in 1RM for the MJ exercises in comparison with the SJ group. Increases in 1RM for the SJ exercises were similar among groups, with the exception of leg curl, where the SJ group obtained greater gains than MJ and MJ+SJ. All groups obtained significant increases in MT from pre- to post-training for all muscle groups. However, MJ and MJ+SJ groups presented greater increases in gluteus maximus, quadriceps femoris and pectoralis major in comparison with the SJ group. Therefore, our results suggest that, in general, performing MJ exercises seems to be necessary to obtain optimal results from a resistance training program; however SJ might be necessary to provide optimal strength gains in knee flexion.

The relationship between fitness variables and performance factor in keirin

Purpose The purpose of this study was to examine the relationship between the track records and physical abilities in elite cyclists(keirin). Methods Twenty three elite cyclists were measured height, weight, lower body circumference(thigh, calf, and ankle), basal physical abilities(grip/back muscle strength, 25m sprint, Sargent jump test, Burpee test, shuttle run test), one-repetition maximum(1RM) strength(back squat, bench press, leg curl, power clean, dead-lift, leg press), aerobic capacity(V̇O2max, METs, HRmax), and track records(200m and 500m). Stepwise multiple regression analyses were performed to investigate which physical abilities related to track records. Results A statistically significant relationship was found between 200m track records and 2 variables which were the thigh circumference and 1RM leg press(p&lt;.05). Also, the thigh circumference and 1RM leg press were significantly related to 500m track records(p&lt;.05). Conclusions The results showed that the thigh circumference and maximal strength were associated with the track records in elite cyclists(keirin).

Menopausal Status Impairs Acute Inflammatory Recovery from Resistance Exercise

The purpose of this study was to explore the effects of menopausal status on inflammatory responses to a single bout of resistance exercise (RE). Twenty pre- (N=10) or post- menopausal (N=10) women aged 18- 65 years had one repetition maximum (1RM) determined for the chest and leg press, leg and biceps curl, vertical pull down, triceps and leg extension exercises. On a separate day, participants completed a session of full body resistance exercise (RE) during which subjects performed three sets of 10 repetitions at 75% 1RM for the aforementioned exercises. Blood samples were obtained prior to, immediately, and one hour after exercise. Changes in interleukin-6, -10, and transforming growth factor beta (IL-6, -10, and TGF-β1) were determined via enzyme-linked immunosorbent assays (ELISA). IL-6 significantly increased (P&lt;0.05) over time in both groups. Immediately post exercise levels of IL-10 were significantly lower (P&lt;0.05) in the post-menopausal group. Changes in IL-10 correlated with 17β-estradiol levels (r2=0.45, P&lt;0.001). Menopausal status impaired inflammatory recovery following acute RE. These changes may be attributed to menopause-induced perturbations to the hormonal milieu.

Cluster vs. traditional training programmes: changes in the force–velocity relationship

ABSTRACT 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.

Comparing the effects of resistance exercise type on serum levels of oxidative stress and muscle damage markers in resistance-trained women

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 < 0.05 level. The results indicated that one bout of hypertrophy-, strength-, and power-type resistance exercises had no significant effects on H2O2, MDA, and total LDH levels. However, serum total CK level significantly increased after all the three types of resistance exercise. Power resistance exercise resulted in a higher total CK level than hypertrophy and strength types. Although the three types of hypertrophy, strength, and power exercise cause muscle damage, they do not exacerbate oxidative stress in resistance-trained women.

The effect of essential oil of rosemary on eccentric exercise-induced delayed-onset muscle soreness in non-active women

Muscle soreness is a problem associated with physical activities. Recently, the medicinal herbs are strategies to prevent muscle soreness. The present study aims were to determine the effect of rosemary essential oil on the responses of lactate dehydrogenase, creatine kinase (CK), lymphocytes, neutrophils, muscle swelling (MS) and muscle pain (MP) following eccentric leg curl exercise in non-active women. 24 non-active females voluntarily participated in this study and were randomly assigned into three groups: rosemary dose 1 (RD1) (n=8; 0.25 ml), rosemary dose 2 (RD2) (n=8; 0.5 ml) and placebo (n=8; 0.5 ml olive oil). Participants in supplement groups consumed the desire amounts of rosemary essential oil every 8 h per day for 14 days. Then, the eccentric leg curl exercise was performed. The supplementation continued until 72 h after exercise. The serum variables, as well as, MS and MP were measured before, 24, 48 and 72 h after exercise. Data were analysed using repeated measure analysis of variance and P≤0.05 considered as significant. The results showed that rosemary significantly decreases CK in RD2 compared with placebo and RD1 48 h after exercise. There was no other significant difference in other serum variables. In conclusion, the present study showed a beneficial effect of rosemary on 48-h post-exercise serum CK concentration (a muscle damage indicator).

Slow-Speed Resistance Training Increases Skeletal Muscle Contractile Properties and Power Production Capacity in Elite Futsal Players.

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.

Changes in Torque-Angle Profiles of the Hamstrings and Hamstrings-to-Quadriceps Ratio After Two Hamstring Strengthening Exercise Interventions in Female Hockey Players.

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, 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.

Electromyographic activity of vastus lateralis muscle of dominant thigh (right) in relation to performance levels during the leg/knee extension exercise performance with 30 repetition maximum load

CONTEXT: Leg/knee exercise has been extensively used to study the electromyographic (EMG) activity of the quadriceps muscle group. However, conducted studies have several limitations related to methodology. AIMS: To assess the effect of performance level on the EMG activity of the vastus lateralis (VL) muscle of the dominant thigh (right) during the performance of leg/knee extension exercise with 30 repetition maximum load. Thigh dominance was based on the result of leg dynamometer. SETTING AND DESIGN: The study was a cross-sectional study, and data collection was conducted in Indira Gandhi Institute of Physical Education and Sports Sciences, University of Delhi, India. MATERIALS AND METHODS: Healthy intercollegiate-level male sportspersons (n = 19, age = 19.84 ± 2.1 years, height = 171.38 ± 8.48 cm, and weight = 70.42 ± 13.8 kg) were randomly selected as the subjects. Leg extension exercise was performed on Cybex VR1 leg curl exercise device and EMG data were acquired using a 4-Channel Wireless EMG BIOPAC Inc. MP150 system. A criterion called relative impulse (RI) was developed. Based on the magnitude of RI of the subject, nine subjects were enlisted and were equally divided into high-performance (HP), mid-performance (MP), and low-performance (LP) groups. The raw EMG signals were quantified, and time-domain (root mean square [RMS] and integrated EMG [IEMG]) and frequency-domain variables (Median Frequency [MDF] and Mean Frequency [MNF]) were derived with the help of? MATLAB. STATISTICAL ANALYSIS USED: One-way analysis of variance and least significant differences (at P RESULTS: All three groups (HP, MP, and LP) displayed a declining pattern in the EMG activity of the VL in the selected variables, except MP group in the MDF, MNF, and RMS. Significant effect of performance level was observed between LP and HP groups and between MP and HP groups in MDF and MNF (P CONCLUSION: The findings are useful for understanding muscular fatigue as they focus on its electrophysiological aspect.

Static Stretch Performed After Strength Training Session Induces Hypotensive Response in Trained Men.

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.

Effect of low-intensity resistance training with blood flow restriction on serum VEGF level, bone markers and bone mineral density in elderly women

Purpose The purpose of this study was to investigate the effects of low-intensity resistance training with blood flow restriction on serum VEGF, bone markers and bone mineral density in elderly women. Methods The subjects were divided into three groups: low-intensity resistance training with blood flow restriction(BFR-LRT, n=8); high intensity resistance training(HRT, n=8); low- intensity resistance training (LRT, n=5). Both the BFR-LRT and LRT groups worked out knee extension and leg curl exercises at 20% of each estimated one-repetition maximum(1RM) and HRT group worked out knee extension and leg curl exercises at 70% of each estimated 1RM 3 days per week for 12 weeks. Results As a result after 12 weeks, serum VEGF level have increased significantly among BFR-LRT group compared to HRT and LRT groups. Serum Bone ALP level have increased significantly among BFR-LRT and HRT groups compared to LRT group. Calcaneus BMD have increased significantly among BFR-LRT and HRT groups compared to LRT group. Conclusions In conclusion, despite using low-intensity load, BFR-LRT is a efficient training alternative to HRT for improving bone metabolism in older women.

Superimposed Whole-Body Electrostimulation Augments Strength Adaptations and Type II Myofiber Growth in Soccer Players During a Competitive Season.

BackgroundThe improvement of strength and athletic performance during a competitive season in elite soccer players is a demanding task for the coach.AimsAs 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.HypothesisWe hypothesized that a superimposed WB-EMS will increase maximal strength and type I and type II myofiber hypertrophy.MethodsTwenty-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.ResultsMaximal 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.ConclusionWB-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.

Effects of Static and Dynamic Stretching Performed Before Resistance Training on Muscle Adaptations in Untrained Men.

Ferreira-Júnior, JB, Benine, RPC, Chaves, SFN, Borba, DA, Martins-Costa, HC, Freitas, EDS, Bemben, MG, Vieira, CA, and Bottaro, M. Effects of static and dynamic stretching performed before resistance training on muscle adaptations in untrained men. J Strength Cond Res 35(11): 3050-3055, 2021-This study evaluated the effects of dynamic and static stretching (SS) performed before resistance training on biceps femoris hypertrophy and knee flexor strength gains in untrained young men. Forty-five untrained young men (age, 21.2 ± 0.5 years; mass, 72.2 ± 5.6 kg; height, 178 ± 1 cm) were randomly assigned to 1 of the 3 groups: (a) 80 seconds of SS (n = 14); (b) 80 seconds of dynamic stretching (DS, n = 13); or (c) control group (CON, n = 18) in which subjects performed no stretching before exercise. Both SS and DS were performed before resistance exercise. Resistance training consisted of 4 sets of 8-12 repetition maximum of seated leg curl exercise 2 days per week for 8 weeks, with a period of at least 48 hours between sessions. Unilateral biceps femoris muscle thickness (MT) and maximal isometric strength (MIS) of the knee flexors were measured 1 week before training and 1 week after the last training session. There were significant increases in MIS (SS = 13.9 ± 10.3 kgf; DS = 10.2 ± 13.1 kgf; CON = 12.7 ± 7.6 kgf; p < 0.05) and MT (SS = 6.0 ± 3.5 mm; DS = 6.7 ± 4.1 mm; CON = 5.7 ± 3.0 mm; p < 0.05) with no significant differences across groups (p > 0.05). Additionally, all groups demonstrated moderate effect sizes for MIS (1.27-1.4), and DS was the only group that had a large effect size for MT increases (DS = 2.18; SS = 1.35; CON = 0.92). In conclusion, 80 seconds of SS and DS did not induce any additional muscular adaptations to resistance training in untrained young men.