Leg Curl Research Articles

How effective is circuit training on physical fitness? A high-intensity study in the sport of futsal

Background and Study Aim. Physical fitness is a crucial component that supports optimal performance in sports, including futsal, which demands a combination of endurance, strength, agility and speed. This study aims to analyze the effectiveness of high-intensity circuit training on improving the physical fitness of futsal players. Material and Methods. The research design used a one group pretest-posttest design method, with participants as many as 8 futsal athletes selected using purposive sampling technique. The study was conducted under partly cloudy weather conditions with real-time temperature of 25.3°C, humidity of 94%, and wind speed of 19.4 km/h. This exercise uses 14 fitness equipment, namely triceps, leg press, front pull down, calf raise, butterfly, leg extension, bench press, sit-up, back-up, standing rowing, squat, back pull down, bicep, and leg curl. Exercises were performed in 3 sets per session with maximum repetitions (1 RM) and rest between sets for 4-5 minutes. The program was implemented for 12 sessions, with full intensity 3 times a week. The instrument was carried out using the Yo-Yo Intermittent Recovery Test Level 1. Data analysis was assisted using the SPSS 26 application Results. The results showed a significant increase in physical fitness after the treatment was given. The mean pretest and posttest values were statistically different (t = -4.190; p < 0.05), with an average improvement of -1.36250. High-intensity circuit training proved to be effective in improving the physical fitness of futsal players, which includes an increase in aerobic capacity and physical strength. Conclusion. This study provides scientific evidence that high-intensity circuit training is an efficient method to improve the physical performance of futsal players. These findings can serve as a reference for coaches in designing relevant and measurable futsal sport needs-based training programs.

Effects of static stretching and specific warm-up on the repetition performance in upper- and lower-limb exercises in resistance-trained older women

IntroductionPreparation methods are often used to improve performance (e.g., number of repetitions) within the resistance training session. However, there is still no consensus in the scientific literature on whether there is a superior preparation method for improving performance, particularly in older adults.MethodsWe compared the effects of preparation by specific warm-up (SW), static stretching (SS), and control condition (CC) on the total number of repetitions in four exercises: leg extension, triceps pushdown, seated leg curl, and preacher curl. Fifty-seven older women (≥ 60 years) performed the experimental protocols (SW and SS) and the CC in a cross-over and counterbalanced design. Following the preparation protocol, the main exercises were performed in two sets until volitional concentric failure, with a two-minute rest interval between sets and 2–3 min between exercises. The main outcome was the total number of repetitions.ResultsThe SS improved performance compared to the SW and the CC in the leg extension and seated leg curl resistance exercises. In contrast, the SW impaired performance compared to the SS and CC in the triceps pushdown and preacher curl exercises.ConclusionOur results suggest that SS may improve performance in lower-limb exercises, while the SW appears to negatively affect performance in upper-limb exercises in resistance-trained older women.

Efficacy of Blood Flow Restriction Exercise for Improving Lower Limb Muscle Strength and Function in Chronic Spinal Cord Injury: A Randomized Controlled Trial.

The objective of the present study was to evaluate the efficacy of low-load (LL) blood flow restriction exercise (BFRE) for improving lower limb muscle strength, muscle thickness and physical function in individuals with spinal cord injury (SCI). In a randomized sham-controlled trial, 21 participants (age ≥ 18 years, SCI duration ≥ 1 year, knee extensor strength grade 2-4, ASIA A-D) were randomized to either 45-min LL-BFRE (n = 11) or sham BFRE (n = 10) twice/week for 8 weeks. The exercise protocol consisted of four sets (30 × 15 × 15 × 15 repetitions) of unilateral seated leg extensions and leg curls at 30%-40% of 1RM performed with pneumatic cuffs applied proximally on the trained limb and inflated to 40% of total arterial occlusion pressure (BFRE) or non-inflated (sham exercise). Maximal voluntary isometric quadriceps and hamstring muscle strength, quadriceps muscle thickness, thigh circumference, and physical function were assessed at baseline, after 4 and 8 weeks of training and at 4-week follow-up. No significant between-group differences were found between BFRE and sham exercise in quadriceps or hamstring muscle strength, 10-m walking test, timed up & go, 6-min walking test or the spinal cord independence measure. In contrast, a significant between-group difference favoring BFRE was present for muscle thickness and thigh circumference from baseline to 4-week follow-up (0.76 cm (95% CI: 0.32; 1.20, p = 0.002) and 2.42 cm (0.05; 4.79, p = 0.05), respectively). In conclusion, there was no significant difference in the effect of LL-BFRE and sham exercise on muscle strength and physical function in individuals with SCI. However, significant increases in muscle thickness and thigh circumference were observed in favor of BFRE. Trial Registration: ClinicalTrials.gov identifier: NCT03690700.

Reliability of the Repetition-to-Fatigue Method for Estimating 1-Repetition Maximum in Unilateral Strength Exercises and Its Relationship With Gait Tests in People With Multiple Sclerosis.

To analyze the reliability of the estimated 1-repetition maximum (e1RM) through the repetition to fatigue method in 4 unilateral resistance training exercises performed using weight machines (ie, leg press, calf raises, leg extension, seated leg curl), and their relationship to gait-related tests. Cross-sectional study. University sports complex. Twenty-four participants with multiple sclerosis (N=24) completed 3 testing sessions. They performed 3 testing sessions that were integrated into a long-term multimodal exercise regime comprising strength, balance, and functional mobility exercises, conducted twice a week in 90-minute sessions. The first session consisted in the assessment of the gait-related tests (ie, timed up and go test [TUG], timed 25-foot walk test [T25FW], 6-minute walk test [6MW]). Two testing sessions were dedicated to the assessment of the e1RM in the aforementioned exercises. Intraclass correlation coefficients (ICC2.1) of absolute e1RM ranged from 0.92 to 0.97 and they were slightly higher than those relative to the body mass (0.85<intraclass correlation coefficient 2.1<0.96). Typical errors for the 4 exercises ranged between 2.2 and 4.7 kg (9.3%-11.6%). The weaker leg e1RM for the calf raises and leg curl exercises were significantly associated with the 6MW (0.654≤r≤0.677), T25FW (-0.555≥r≥-0.557), and TUG (-0.480≥r≥-0.526). Between-leg e1RM asymmetries in these exercises were also correlated with the 6MW (0.420≤r≤0.467), T25FW (0.553≤r≤0.590), and TUG (0.626≤r≤0.627). Unilateral e1RMs during the leg press and leg extension showed no or few significant associations with gait-related tests. The results suggest that e1RM can be safely and reliably performed to quantify single-leg strength and to control the training load in these exercises. Knee flexors and ankle extensors strength, especially of the weaker leg, along with their asymmetry, seem to be the most relevant factors to consider in the strength assessment and training of this population.

Resistance training improves functional capacities in women with multiple sclerosis: a randomized control trial

PurposeThis study aimed to investigate the effects of 12 weeks of resistance exercise training (RT) on oxidative status, muscle strength, functional capacity, quality of life (QoL), and fatigue in women with Multiple Sclerosis (MS).MethodsIn this randomized control trial (ethical code: SSRI.REC-1402-101; IRCT registration code: IRCT20120912010824N3, 07.09.2023), Iran) twenty-five women with relapsing- remitting MS (aged 18–45 years and expanded disability status scale (EDSS) ≤ 4) were randomly divided in two groups MS without resistance exercise (MS + non-RT; n = 13) and with RT (12 weeks/3 times per week/ 60–80% of 1RM) (MS + RT; n = 12). “Informed” consent was obtained from all participants. Then, fifteen healthy aged-matched women participated as a control group (HCON; n = 15). Blood serum levels of oxidative stress [malondialdehyde (MDA)] and antioxidant capacity [superoxide dismutase (SOD) and glutathione peroxidase (GPx) activity] were obtained pre and post intervention. In addition, muscle strength by 5-RM test, functional capacity (for lower limb T25FWT, 2MWT, and 5STS tests and for Upper limb Manual dexterity of both hands with the (9-HPT) test and MSWS-12 questionnaire were also assessed over the same period. Also, Quality of life and fatigue were assessed pre- and post- intervention with by 31-MusiQoL questionnaire and FSMC questionnaire.ResultsRT led to improvements in muscle strength for leg extension, lying leg curl, bench press movements (P < 0.001, P < 0.001, P < 0.001, respectively). Moreover, compared with the MS + non-RT group, RT demonstrated increased functional capacity (Timed 25 ft Walk Test, Two-Minute Walk Test, 5-Time Sit-To-Stand Test, Twelve Item MS Walking Scale (P < 0.001, P < 0.001, P < 0.001, P < 0.001, respectively). Dexterity of the left hand but not the right hand also improved (P < 0.01, P = 0.057, respectively). Improvements were also found for fatigue and QoL (P < 0.01, P < 0.05). However, the mean changes of MDA, SOD and GPx noted in RT group were not statistically significant (P˃0.05, P˃0.05, P˃0.05, respectively).ConclusionsRT has positive effects on muscle strength, functional capacity, and quality of life while reducing fatigue in this population. However, markers of oxidative stress were not affected. When we consider the clear role in MS pathogenesis and progression, antioxidant increases in relation to a reduction in pro-oxidant capacity would have provided a positive and important clinical development for people with MS.

Impact of resistance training and chicken intake on vascular and muscle health in elderly women.

Resistance training is a well-known exercise therapy for preventing and improving lacks of muscle mass, strength, and quality with advances in age; however, its effects on arterial stiffness are not beneficial. Additionally, a higher intake of protein, which is an effective nutrient for muscle health, results in lower arterial stiffness. Whether the combination of moderate to high-intensity resistance training and high-protein intake would improve muscle mass, strength, and quality and cancel the resistance training-induced increase in arterial stiffness in elderly women remains unclear. Ninety-three elderly women (67.2±5.3years) were randomly divided into four groups; sedentary control (CON), higher dietary animal protein intake (HP), resistance training (RT), and combination of RT and HP (RT+HP) groups. Participants in the RT and RT+HP groups completed 12weeks of resistance training (exercise intensity at 70% of one-repetition maximum (1-RM), three sets with 10 repetitions of leg extension and curls, 3days/week). In addition to the daily diet, the HP and RT+HP groups consumed steamed chicken breast as a high-protein diet. Percent changes in thickness (indices of muscle mass) and echo intensity (index of muscle quality) in the quadriceps muscle, 1-RM of leg extension and curls (index of muscle strength), and circulating C1q levels (a potential biomarker of muscle fibrosis) in the RT and RT+HP groups significantly improved after both RT and RT+HP interventions (P<0.05). Percent changes in carotid-femoral pulse wave velocity (cfPWV) and carotid β-stiffness (indices of arterial stiffness), and circulating angiotensin II (a vasoconstrictor peptide hormone) levels via each intervention were significantly higher in the RT group (4.9±12.7%, 13.8±13.5%, 94.9±132.7%, respectively), as compared with the CON group (-2.5±5.9%, 0.2±8.1%, 21.2±79.3%, respectively) (P<0.05). Of note, no significant differences in the cfPWV, carotid β-stiffness, and circulating angiotensin II levels between the RT+HP (-2.4±9.3%, 2.4±10.3%, -5.7±29.6%, respectively) and CON groups were observed. Furthermore, significant positive relationships between the percent changes in circulating angiotensin II levels, and cfPWV (r=0.438, P<0.01) and carotid β-stiffness (r=0.328, P<0.01) were observed. The combination of moderate to high-intensity resistance training and regular intake of steamed chicken breast as a high-protein food could increase muscle mass, strength, and quality and could cancel resistance training-induced increases in arterial stiffness in elderly women.

The effects of plyometric versus resistance training on running economy and 5-km running time in middle-aged recreational runners.

The effects of plyometric training (PT) versus resistance training (RT) on running economy and performance are unclear, especially in middle-aged recreational runners. We examined (1) the efficacy of PT versus RT on running economy and performance in middle-aged recreational runners and (2) the relationships between the main training outcomes. Twenty middle-aged recreational runners were randomly allocated to a PT or RT group (n=10/group). Training was conducted twice/week for 10weeks combined with daily running. PT included the countermovement jump (CMJ), rebound jump, hurdle hop, and drop jump. RT consisted of leg press, leg curl, and calf raise with 50%-90% of one-repetition maximum (1RM). Before and after the intervention, 1RM of the three lifting tasks, CMJ and drop jump performances, oxygen cost at 8-12km/h, and 5km running time were assessed. PT enhanced 1RM of leg curl only (8.5% and p=0.007), whereas RT increased 1RM of the three lifting tasks (19.0%-21.1% and p<0.001). Both groups improved CMJ height (6.4%-8.3% and p=0.016) and drop jump performance (height: 9.7%-19.4%, p=0.005, height/contact time: 11.4%-26.3% and p=0.009) and oxygen cost regardless of running velocity (2.0% and p=0.001) without significant group differences. However, neither group changed the 5-km running time (p≥0.259). A significant correlation was found between the changes in calf raise 1RM and oxygen cost (r=-0.477 and p=0.046) but not between the other measured variables. These results suggest that for middle-aged recreational runners, PT and RT can similarly improve running economy albeit not necessarily the 5-km running time, and enhancing plantarflexion strength may particularly contribute to improving running economy.

Acute cardiovascular responses of postmenopausal women to resistance training sessions differing in set configuration: A study protocol for a crossover trial.

Resistance training is hardly recommended for postmenopausal women to counteract negative effects of hormonal changes. However, some concern exists about the marked hemodynamic responses caused by high-load resistance exercises. In this regard, studies on young, healthy, physically active individuals suggest that set configuration can modulate acute cardiovascular, metabolic, and cardiac autonomic responses caused by resistance training sessions, but this has not yet been explored in postmenopausal women. A sample of 60 physically active postmenopausal women (30 normotensive, 30 hypertensive) will participate in this crossover study. After a medical exam, ergometry, familiarization session, and two testing sessions, participants will complete three experimental sessions and one control session in a randomized order. Each experimental session includes 36 repetitions of four exercises (horizontal leg press, bench press, prone leg curl, and lat pull-down) differing in set configuration: 9 sets of 4 repetitions (i.e., 33% intensity of effort) with 45 s of inter-set recovery, 6 sets of 6 repetitions (50% intensity of effort) with 72 s, and 4 sets of 9 repetitions (75% intensity of effort) with 120 s; with 4 min rest between exercises. Before and immediately after each session, arterial stiffness, hemodynamic variables, cardiac autonomic modulation, baroreflex sensitivity, sympathetic vasomotor tone, and resting oxygen uptake will be evaluated. Furthermore, perceived effort, mechanical performance (e.g., power, velocity), heart rate, and lactatemia will be collected throughout sessions. The impact of set configuration on these variables will be analyzed, along with comparisons between normotensive and hypertensive women. Cardiovascular responses to resistance exercise have been scarcely studied in females, particularly postmenopausal women. The results of this study will provide information about the modulating role of set structure on metabolic and cardiovascular responses of normotensive and hypertensive postmenopausal women to resistance training. NCT05544357 on 7 December 2022.

Muscle Hypertrophy and Strength Adaptations to Systematically Varying Resistance Exercises

ABSTRACT We compared the effects of varied and constant resistance exercises on muscular adaptations in young women. Seventy young women (21.8 ± 3.4 yrs, 62.0 ± 12.3 kg, 162.3 ± 5.7 cm) were randomly divided into two groups: constant resistance exercises (CON-RE, n = 38) or varied resistance exercises (VAR-RE, n = 32). The resistance training (RT) was performed thrice a week over 10 weeks. CON-RE performed a 45º leg press and stiff-leg deadlift in every training session, while VAR-RE performed 45º leg press and stiff-leg deadlift in the first training session of the week, hack squat and prone leg curl in the second, and Smith machine squat and seated-leg curl in the third. Both groups performed two sets of 10–15 repetitions maximum per resistance exercise. We measured the muscle thickness of the thigh’s anterior, lateral, and posterior aspects by ultrasonography at different muscle sites (proximo-distal). Muscular strength was analyzed from the one-repetition maximum (1RM) tests in the 45° leg press and leg extension (non-trained exercise). The muscle thickness increased similarly in both groups for all muscles and sites (CON-RE: +7.8–17.7% vs. VAR-RE: +7.5–19.3%, p > .05). The 1RM increased similarly in both groups (CON-RE: +24.4–32.1% vs. VAR-RE: +29.0–30.1%, p > .05). Both RT routines resulted in virtually similar muscular strength gains and hypertrophy. Therefore, both strategies should be considered for the improvement of strength and muscle growth.

Progression and perceptual responses to blood flow restriction resistance training among people with multiple sclerosis.

Resistance exercise can attenuate muscular impairments associated with multiple sclerosis (MS), and blood flow restriction (BFR) may provide a viable alternative to prescribing heavy training loads. The purpose of this investigation was to examine the progression of upper and lower body low-load (30% of one-repetition maximum [1RM]) resistance training (RT) with BFR applied intermittently during the exercise intervals (RT + BFR) versus volume-matched heavy-load (65% of 1RM) RT. Men and women with MS (n = 16) were randomly assigned to low-load RT + BFR (applied intermittently) or heavy-load RT and completed 12weeks (2 × /week) of RT that consisted of bilateral chest press, seated row, shoulder press, leg press, leg extension, and leg curl exercises. Exercise load, tonnage, and rating of perceived exertion were assessed at baseline and every 6 weeks. Training load increased to a greater extent and sometimes earlier for RT + BFR (57.7-106.3%) than heavy-load RT (42.3-54.3%) during chest press, seated row, and leg curl exercises, while there were similar increases (63.5-101.1%) for shoulder press, leg extension, and leg press exercises. Exercise tonnage was greater across all exercises for RT + BFR than heavy-load RT, although tonnage only increased during the chest press (70.7-80.0%) and leg extension (89.1%) exercises. Perceptions of exertion (4.8-7.2 au) and compliance (97.9-99.0%) were similar for both interventions. The training-induced increases in load, high compliance, and moderate levels of exertion suggested that RT + BFR and heavy-load RT are viable interventions among people with MS. RT + BFR may be a preferred modality if heavy loads are not well tolerated and/or to promote early-phase training responses.

Low-Load Resistance Exercise With Blood Flow Restriction Versus High-Load Resistance Exercise on Hamstring Muscle Adaptations in Recreationally Trained Men.

Kamiş, O, Gürses, VV, Şendur, HN, Altunsoy, M, Pekel, HA, Yıldırım, E, and Aydos, L. Low-load resistance exercise with blood flow restriction vs. high-load resistance exercise on hamstring muscle adaptations in recreationally trained men. J Strength Cond Res XX(X): 000-000, 2024-Low-load resistance exercise with blood flow restriction (BFR-RE) has been suggested as a viable alternative exercise for traditional high-load resistance exercise (HL-RE). However, very little is known about hamstring muscle thickness, stiffness, and strength after BFR-RE. This study aimed to compare the effects of 6 weeks of BFR-RE and HL-RE on hamstring muscle thickness, stiffness, and strength. Twenty-nine recreationally trained men were pair matched and randomly assigned to the BFR-RE (n = 15) and HL-RE (n = 14) groups. The BFR-RE groups performed bilateral lying leg curl exercise (30-15-15-15 reps, 30-second rest between the sets, 30% 1RM) with BFR cuffs (60% of limb occlusion pressure), whereas HL-RE performed the same exercise (3 × 12 reps, 90-second rest between the sets, 70% 1RM) without BFR cuffs. Hamstring muscle thickness, muscle stiffness, isokinetic muscle strength, and 1RM were assessed at baseline and follow-up after completing a 6-week resistance exercise program (3× a week). Hamstring muscle thickness was assessed by ultrasonography, whereas muscle stiffness was evaluated by shear wave elastography. Isokinetic dynamometry and a 1RM strength test were used to determine muscular strength before and after the exercise program. Statistical significance was set at p < 0.05. No significant effect was found for hamstring muscle strength, thickness, and stiffness for group and group × time interaction, and only a significant main effect of time (p < 0.001) was observed for all outcomes. Both groups experienced significant improvements for all outcomes from baseline to follow-up without any between-group differences. In conclusion, results revealed that BFR-RE can provide similar hamstring muscle strength, thickness, and stiffness compared with HL-RE.

Delayed Onset Muscle Soreness Following Acute Resistance Exercise in Untrained Females: A Comparative Study Between Vegans and Omnivores.

This study aimed to assess the levels of delayed onset muscle soreness (DOMS) markers in individuals adhering to vegan and omnivore diets after engaging in acute resistance exercise. A total of 54 untrained young, healthy, normal-body-weight women (age: 26.8±4.1 years; body mass index: 22.5±2.7 kg/m2) participated in the study. Participants were categorized into two groups: vegans (n=27) and omnivores (n=27) based on their dietary preferences, with all subjects having adhered to their respective diets for a minimum of 2 years. DOMS was induced by a single eccentric resistance exercise session, comprising four exercises (leg press, chest press, leg curls, and arm curls), each consisting of four sets of 10 repetitions. Various measurements, including dietary factors, state of wellness, body composition, muscle circumferences, muscle pressure point thresholds (PPTs), and muscle strength, were recorded both before and 48 hours after the exercise session. The results showed that wellness and muscle circumferences remained unchanged or displayed similar changes between the vegan and omnivore groups following acute resistance exercise. However, notable differences were observed in PPTs in favor of vegans, specifically for the right biceps (95% CI: 1.4 to 10.2; p=0.01), the left vastus medialis (95% CI: 0.5 to 6.4; p=0.02), and the right vastus lateralis (95% CI: 3.2 to 12.1; p=0.001). Furthermore, significant differences in right grip strength were found in favor of vegans after the exercise session (95% CI: 3.1 to 26.2; p=0.01). In conclusion, our findings suggest that vegans may experience more favorable changes in DOMS levels following acute resistance exercise in comparison to omnivores. This discrepancy in DOMS markers may indicate enhanced muscle recovery in vegans.

The Effect of Velocity-Based Contraction Strength Training on Performance in Female 400m Athletes

This study aims to compare the differences in strength training at velocity of muscle contraction in 400-meter runners. The sample group consisted of 12 female athletes who participated in the Thailand National Sports competition qualifiers in 2023. The group was divided into two: the first group underwent strength training at a fast muscle contraction rate with 80 bpm, while the second group trained at a normal muscle contraction rate with 40 bpm. The training lasted for 8 weeks, and after a 2-week post-training period, both groups were tested by swapping strength training programs. They were tested for 400-meter speed, strength from finding the 1 RM of Leg curl, Leg extension, and Leg press measured in kilograms, and explosive power from Squat jump, Countermovement jump, and Long jump. The data collected was analyzed to find the average, standard deviation, and one-way ANOVA with a statistical significance level set at .05. From the research's results, it was found that percentage change muscle contraction rates differs significantly between the two strength training formats: one with fast muscle contraction and the other with normal- muscle contraction rate (1.04±0.02 and 1.02±0.02, respectively) at a significance level of .05. Additionally, the strength and explosive power percentage change also significantly differ between the two strength training formats. Therefore, based on this study, it is possible to utilize the fast muscle contraction rate strength training format to enhance the athletic performance of athletes.

Effect of resistance training and chicken meat on muscle strength and mass and the gut microbiome of older women: A randomized controlled trial.

This study investigated the effects of white meat, such as chicken, intake combined with resistance training on muscle mass and strength in the elderly women, and whether the underlying mechanism involves changes in the gut microbiota. Ninety-three volunteers (age 59-79 years) were randomly allocated to sedentary control with placebo (Sed + PL) or chicken meat (Sed + HP) and resistance training with placebo (RT + PL) or chicken meat (RT + HP). Resistance training sessions were performed 3 d/week for 12 weeks using leg extensions and curls. Boiled chicken meat (110 g, containing 22.5 g protein) was ingested 3 d/week for 12 weeks. Maximal muscle strength and whole-body lean mass increased significantly in the RT + PL group compared to the Sed + HP group, and the RT + HP group showed a significantly greater increase than the Sed + HP and RT + PL groups. Additionally, the gut microbiota composition did not change before or after the interventions in any of the four groups. Moreover, the individual comparison of gut bacteria using false discovery rate-based statistical analysis showed no alterations before or after the interventions in the four groups. Resistance training combined with chicken meat intake may effective have increased muscle mass and strength without drastically modifying the gut microbiota composition in elderly women.

Effects of different resistance training programmings on the relative strength, body composition, anthropometric variables, and metabolic risk of elderly women

The purpose of this study was to analyze the effect of two different programming models of resistance training (RT) on metabolic risk, anthropometric variables, and relative strength in elderly women. The research was a prospective and comparative longitudinal study with a non-probabilistic random sample. Twenty-two elderly women (64±3 years) was divided into two experimental groups being the Linear programming (LP, n=12) and Daily undulatory programming (DUP, n=10), with 3 sessions/week for 12 weeks. Submaximal strength (10RM) was evaluated in the horizontal leg press (HL), pulldown (PD), leg curl (LC), vertical bench press (BP), and leg extension (LE). Anthropometric variables, food intake (R24h) and submaximal strength (10RM) was analyzed. Participants were initially classified as overweight or obese evaluated by body mass index (BMI) and percentual of fat mass (%FM) and with moderate to high risk to develop metabolic diseases evaluated by hip-waist ratio (HWR), waist-height ratio (WHR) and waist circumference (WC). There is no change for metabolic risk and anthropometric variables after the intervention period. There was a significant improvement for relative strength accessed by 10RM and body weight (10RM/BW), and lean body mass (10RM/LBM) (p<0.05), with large or medium effect size for most of variables after 12 weeks of RT. As a conclusion, both programmings increased relative strength after 12 weeks of RT with attenuated change in body composition and metabolic risk in elderly women in both programming groups and all those strategies can be used in elderly women to improve strength.

Effects of Whole-Body Vibration Combined with Blood Flow Restriction and Systemic Hypoxia on Body Composition and Physical Performance in Overweight University Students

Study purpose. This study investigated the effects of whole-body vibration (WBV) combined with blood flow restriction (BFR) and hypoxic exposure (HYP) on body composition and physical performance in overweight university students. Materials and methods. Twenty-nine male university students with overweight were divided into 3 groups: 1) whole-body vibration (WBV), 2) whole-body vibration plus blood flow restriction (WBV+BFR, 60% of occlusion pressure) and 3) whole-body vibration plus hypoxic exposure (WBV+HYP, FiO₂ = 15.8%). Training included 10 sets of intermittent WBV exercise (30-35 Hz in frequency and high amplitude) 20 min/day and 3 days/week. Body composition along with physical performance was measured before (2-3 days prior) and after (2-3 days post) an 8-week training period. Results. The results of this study were as followed, after training, the maximum strength (1RM) in the leg press and leg curl were significantly increased in the WBV+HYP group (28.31%, p = 0.016 and 13.56%, p = 0.017) compared with the WBV group (17.68% and 2.88) respectively. Similarly, the WBV+HYP group showed a substantial increase in muscle endurance in the leg extension and leg curl (28.57%, p = 0.013 and 34.38% p = 0.049) when compared to the WBV group (5.33% and 13.20%) respectively. Conclusions. Whole-body vibration combined with blood flow restriction and hypoxic exposure were effective in improving body composition and physical fitness. Performing the procedure can also be adjusted according to convenience and suitability for each individual. It is a guideline for preventing, treating, and promoting health among overweight adolescents.

Sex differences in muscle-quality recovery following one week of knee joint immobilization and subsequent retraining.

This manuscript represents the second phase of a clinical trial designed to examine the effects of knee joint immobilization and retraining on muscle strength and mass. In Phase 2, we examined sex differences in the recovery of multiple indices of muscle quality after a resistance training-based rehabilitation program. Following 1 week of immobilization, 27 participants (16 males, 11 females) exhibiting weakness underwent twice weekly resistance training sessions designed to re-strengthen their left knee. Unilateral retraining sessions utilizing leg press, extension, and curl exercises were conducted until participants could reproduce their pre-immobilization knee extension isometric maximal voluntary contraction (MVC) peak torque. Post-immobilization, both sexes demonstrated impaired MVC peak torque (males = -10.8%, females = -15.2%), specific torque (-9.8% vs. -13.1%), echo intensity of the vastus lateralis (+6.9% vs. +5.9%) and rectus femoris (+5.9% vs. +2.1), and extracellular water/intracellular water ratio (+7.8% vs. +9.0%). The number of retraining sessions for peak torque to return to baseline for males (median=1, mean=2.13) versus females (median=2, mean=2.91) was not significantly different, though the disparity in recovery times may be clinically relevant. Following retraining, specific torque was the only muscle-quality indicator that improved along with MVC peak torque (males=20.1%, females=22.4%). Our findings indicate that measures of muscle quality demonstrate divergent recovery rates following immobilization, with muscle mass lagging behind improvements in strength. Greater immobilization-induced strength loss among females suggests that sex-specific rehabilitation efforts may be justified.

Resistance Training Practices of Brazilian Olympic Sprint and Jump Coaches: Toward a Deeper Understanding of Their Choices and Insights (Part III).

In the final part of this three-article collection on the training strategies of Brazilian Olympic sprint and jump coaches, we provide a detailed description of the resistance training methods and exercises most commonly employed by these speed experts. Always with the objective of maximizing the sprint and jump capabilities of their athletes, these experienced coaches primarily utilize variable, eccentric, concentric, machine-based, isometric, complex, and isoinertial resistance training methods in their daily practices. Squats (in their different forms), Olympic weightlifting, ballistics, hip thrusts, lunges, calf raises, core exercises, leg curls, stiff-leg deadlifts, and leg extension are the most commonly prescribed exercises in their training programs, during both the preparatory and competitive periods. Therefore, the current manuscript comprehensively describes and examines these methods, with the additional aim of extrapolating their application to other sports, especially those where sprint speed is a key performance factor.

Conventional Ratio of Knee Flexors and Extensors Obtained Using an Isokinetic Dynamometer and Isoinertial Devices

This study aimed to analyze the conventional ratio values of knee flexors and extensors obtained using an isokinetic dynamometer (IsoRatio), an adjusted torque test of 5RM (Ratio5RM), and absolute values of 5RM (Ratio5RML). Fifteen male volunteers (28.47 ± 5.78 years; 78.30 ± 6.59kg; 1.79 ± 0.65m) performed a 5RM test on leg extension and leg curl machines. The volunteers executed knee flexion and extension movements at 60°/s angle speed without significant differences between protocols. Regression analysis showed that the Ratio5RML correlates with the isokinetic reference ratio (r=0.649; p=0.009). The result of the paired t-test showed no significant difference between the means of the isokinetic ratio and the ratio predicted by the equation. The results of the present study suggest that the 5RM test performed with isoinertial machines can be used to estimate conventional ratio and identify imbalance between the knee flexors and extensors muscles.

Six Weeks of Unilateral Flywheel Hip-Extension and Leg-Curl Training Improves Flywheel Eccentric Peak Power but Does Not Enhance Hamstring Isokinetic or Isometric Strength.

This preregistered trial investigated how 6 weeks of unilateral flywheel leg-curl and hip-extension training impact isokinetic, isometric, and flywheel strength and power outcomes. The study involved 11 male university athletes (age 22 [2]y; body mass 77.2 [11.3]kg; height 1.74 [0.09]m) with one leg randomly allocated to flywheel training and one leg to control. Unilateral eccentric and isometric knee-flexion torque and flywheel unilateral leg-curl and hip-extension peak power were tested. Training intensity and volume (3-4 sets of 6 + 2 repetitions) were progressively increased. The intervention enhanced hip-extension concentric (P < .01, d = 1.76, large) and eccentric (P < .01, d = 1.33, large) peak power more than the control (significant interaction effect). Similarly, eccentric (P = .023, d = 1.05, moderate) peak power was enhanced for the leg curl. No statistically significant differences between conditions were found for isokinetic eccentric (P = .086, d = 0.77, moderate) and isometric (P = .431, d = 0.36, small) knee-flexor strength or leg-curl concentric peak power (P = .339, d = 0.52, small). Statistical parametric mapping analysis of torque-angle curves also revealed no significant (P > .05) time-limb interaction effect at any joint angle. Unilateral flywheel hamstring training improved knee-flexor eccentric peak power during unilateral flywheel exercise but not flywheel concentric, isokinetic eccentric, or isometric (long-lever) knee-flexor strength.