Resistance Training Program Research Articles

Effects of Resistance Training on Spasticity in People with Stroke: A Systematic Review.

Resistance training induces neuromuscular adaptations and its impact on spasticity remains inadequately researched. This systematic review (PROSPERO: CRD42022322164) aimed to analyze the effects of resistance training, compared with no treatment, conventional therapy, or other therapies, in people with stroke-related spasticity. A comprehensive search was conducted up to October 2023 in PubMed, PEDro, Cochrane, Web of Science, and Scopus databases. Selection criteria were randomized controlled trials involving participants with stroke-related spasticity intervened with resistance training. The PEDro scale was used to evaluate the methodological quality. From a total of 274 articles, 23 full-text articles were assessed for eligibility and nine articles were included in the systematic review, involving 225 participants (155 males, 70 females; mean age: 59.4 years). Benefits were found to spasticity after resistance training. Furthermore, studies measuring spasticity also reported benefits to function, strength, gait, and balance. In conclusion, resistance training was superior to, or at least equal to, conventional therapy, other therapies, or no intervention for improving spasticity, as well as function, strength, gait, and balance. However, the results should be taken with caution because of the heterogeneity of the protocols used. Further research is needed to explore the effects of resistance training programs on people with stroke.

Effects of short and long inter-set rest on maximal isokinetic strength at slow and fast angular velocities in trained young males after eight weeks of resistance training

Resistance training is a widely used method to enhance muscle strength, with acute program variables influencing muscle adaptations. This study focused on the often-neglected variable of inter-set rest interval duration and its impact on muscle strength gains. Existing literature presents conflicting findings, with some studies advocating for longer rest intervals, while the others show comparable strength increases with shorter rests. Methodological differences in prescription and sample groups contributed to these inconsistencies. This study investigated the effect of short and long inter-set rests on maximal isokinetic strength gains of the upper and lower extremities during slow and fast angular velocities after eight weeks of resistance training. The research involved 26 healthy strength-trained males (age=20±1 year, body mass=81.5±8.8 kg, body height=184.4±6.1 cm) randomly assigned to G1m (1-minute rest) or G3m (3-minute rest). The resistance training programs were matched for all acute program variables, emphasizing the rest interval as the primary difference. Isokinetic dynamometry pre- and post-training assessed knee and elbow extensor and flexor maximal strength at 60º/s and 120º/s. The training program consisted of seven exercises performed at 70% 1RM until muscle failure three times per week over eight weeks. The most important result was that G3m, in contrast to G1m, led to a higher increase in peak torque of the knee (p=.037) and elbow extensors (p=.007) as well as the elbow flexors (p=.045) at 60º/s. Furthermore, G3m and G1m similarly increased the peak torque of the knee and elbow extensors and flexors at 120º/s and of the knee flexors at 60º/s (p>.138). In conclusion, the study suggests that strength training with longer inter-set rest intervals may lead to similar strength gains as strength training with shorter inter-set rest intervals. Nonetheless, individuals who prioritize maximizing their strength gains are advised to utilize longer rest intervals. However, shorter rest intervals may still yield significant strength enhancements, particularly for those who are limited by time.

Effects of a remotely supervised resistance training program on muscle strength and body composition in adults with cystic fibrosis: Randomized controlled trial

AbstractIntroductionAmong the limited studies on physical exercise interventions in adults with cystic fibrosis (CF), few have specifically addressed the improvement of peripheral muscle strength and body fat‐free mass. The aim of this study was to examine the impacts of a remotely supervised, individualized 8‐week resistance training program of moderate to high intensity on strength and body composition in these subjects.MethodsThis was a randomized controlled trial performed in adults with CF. The exercise group (EX) performed three 1‐h resistance training sessions per week over 8 weeks. The control group (CON) followed the physical activity recommendations of their physician. The main outcomes were muscle strength and body composition, with secondary measures including pulmonary function and quality of life. Two‐way repeated measures analysis was used.ResultsIn 23 participants (age 32.13 ± 7.72 years), the intervention showed a significant beneficial effect on leg press strength, with a large effect size, both in absolute (p = 0.011; = 0.281) and relative (p = 0.007; = 0.310) terms. Large intervention effects were observed on total fat mass (p < 0.001; = 0.415), body adiposity index (p < 0.001; = 0.436), and fat mass index (p < 0.001; = 0.445), all showing reduction in the EX group. In addition, significant large size effects were detected on total fat‐free mass (p = 0.046; = 0.177), trunk fat‐free mass (p = 0.039; = 0.188), and fat‐free mass index (p = 0.048; = 0.174), all favoring exercise. No significant effects were observed on pulmonary function and quality of life.ConclusionsAn 8‐week remotely supervised resistance training program, with moderate to high intensity, effectively improved lower limb muscle strength and body composition.

Exercise leads to better sleep in children with inflammatory bowel disease.

The aim of our study was to investigate the effect of an exercise program on health-related quality of life (HRQoL) and sleep quality in children with inflammatory bowel disease (IBD) in remission. A total of 42 pediatric IBD patients in remission were recruited to participate in a 6-month-long home-based exercise program. Their mean age was 15.3 years (with a range of ± 2.08 years) and there were 25 boys. With regard to disease type, 22 had Crohn's disease (CD), 18 had ulcerative colitis (UC), and two had unclassified inflammatory bowel disease (IBD-U). Prior to starting the program, and after its completion, HRQoL was assessed using the IMPACT III questionnaire, and sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI) questionnaire. Patients also wore a triaxial accelerometer for 5 consecutive days before and after the completion of the exercise program to assess physical activity (PA) objectively. Study participants experienced no significant increase in their IMPACT III score (from 147.6 ± 2.7 to 149.6 ± 2.7, p = 0.106) following the completion of the exercise program. The prevalence of impaired sleep quality (PSQI > 5) decreased significantly from 30.9 to 23.8% (p = 0.027). At the baseline, participants' time spent in light PA (LPA) correlated positively with their IMPACT III score (coefficient (coef.) 0.398, p = 0.013). Following the completion of the resistance training program, the changes in the IMPACT III score correlated positively with time spent in moderate-to-vigorous PA (MVPA) (coef. 0.329, p = 0.047) and negatively with changes in PSQI score (coef. -0.493, p = 0.001). The number of children with impaired sleep quality decreased significantly following the completion of a 6-month-long home-based resistance training program but improvements in HRQoL scores did not reach statistical significance.

Effect of Resistance Training Programs With Equated Power on Older Adults' Functionality and Strength: A Randomized Controlled Trial

Abstract Fraga-Germade, E, Carballeira, E, and Iglesias-Soler, E. Effect of resistance training programs with equated power on older adults' functionality and strength: a randomized controlled trial. J Strength Cond Res 38(1): 153–163, 2024—This study aimed to compare the effect of 2 training programs of equated power but differing in load intensity on older adults' functionality, strength, performance, and body composition. Forty-four active (23 female) older adults (66.3 ± 4.5 years) were randomly assigned to low-load high-velocity (LL-HV), high-load low-velocity (HL-LV), and control (CON) groups. Low-load high-velocity and HL-LV performed, twice weekly for 5 weeks, a resistance training program at 95% of their individual peak power (PP) but with different load intensities for 3 exercises: chest press (CHP), leg press (LP), and seated row (SR). Before and after the intervention, body composition, functional performance, maximal voluntary isokinetic force (MVF), PP, and a relative load-power profile (L-PP) were evaluated for every exercise. PP similarly improved in the experimental groups for SR and LP (p < 0.05). Both groups increased their MVF for the 3 exercises (p < 0.05). Positive effects on L-PP were observed in LL-HV for SR (p = 0.009) and HL-LV for LP (p < 0.001). CON decreased its global power performance in SR (p = 0.009) and CHP (p = 0.031) compared with the baseline. Both experimental groups improved Timed Up and Go performance (p < 0.05), but only HL-LV increased 6-minute walking performance (pre: 514.3 ± 89.0 m, post: 552.6 ± 65.4 m; p < 0.05). In conclusion, adding short-term power training (i.e., 10 sessions throughout 5 weeks) with loads slightly above the optimal load to nonsupervised multicomponent training might improve active older adults' functional performance and cardiovascular endurance.

Application Of Resistance Training And Strength Exercises For Improving Explosive Force In Students Of Sports University Of Tirana

Resistance training is a potent stimulus to the neuromuscular system for muscle hypertrophy and strength gain which is known to have positive effects on health, weight control and performance The capacity for human exercise performance can be enhanced with prolonged exercise training, whether it is endurance or strength-based. The purpose of this study is to analyse the effectiveness of RT performed with strength exercises for improving body composition, muscle strength and explosive force of SUT students. 45 male students of SUT, aged 18-25 years old, had participated in this study. The training period lasted 12 weeks with 3 times per week sessions. The study was performed following a training protocol by control and experimental groups. The paired samples t-test was used to the comparisons within group, whilst the independent samples t-test was used to compare variables between groups at baseline. The main findings of this study is that HIRT procedures improvements in the maximum power output (peak power) and efficiency of the motion at experimental group are slightly greater than those reported at control group and the estimated mean change in maximum power output and efficiency over the training program was 4.08 W/kg and 4.2% efficiency (p < 0.05) when compared the experimental group to control group. In conclusion, the present study suggest that, the high intensity resistance training program composed by functional training, fitness challenge and core & abdominal exercises have the most benefit form improving body composition, peak maximum power, efficiency and explosive force.

Effects of variable intensity and constant intensity flywheel resistance training programs on specific soccer players' performance.

Resistance training programs play a crucial role in optimizing soccer performance. The aim of this study is to compare performance outcomes in sport-specific tasks after implementing two different flywheel resistance training (FRT) programs: variable intensity (VI) and constant intensity (CI). Seventeen (n = 17) amateur footballers were divided into VI and CI groups with the same training volume. For the VI group, a decrease in inertial load was implemented every four sessions, whereas the CI group maintained a constant load during the entire program. After different familiarization sessions and testing (sprint, change of direction, jump, one-repetition maximum and flywheel strength variables), ten sessions of FRT were performed over 5weeks. Both groups showed similar improvements in the one-repetition maximum (p < 0.01) but the CI group had significant improvements in the 10-m sprint (p = 0.04; ES = 0.72), emphasizing the potential benefits of medium inertial loads to maximize power and specificity in sport tasks. However, no significant differences were observed in the countermovement jump, change of direction and 30-m sprint, possibly attributed to neuromuscular fatigue from a high-volume training schedule and friendly matches. The study highlights the importance of considering training load distribution in FRT programs. The findings emphasize the need for complementary training to maximize the jump and change of direction abilities and caution against high-volume training and friendly match scenarios. In conclusion, FRT programs, whether varying in intensity or not, can yield medium-term performance improvements for soccer players.

Whey Protein Supplementation in Older Adults With Type 2 Diabetes Undergoing a Resistance Training Program: A Double-Blind Randomized Controlled Trial.

This study aims to analyze the effect of whey protein (WP) supplementation on glycemic control, muscle strength, quality of life, and body composition in older adults with non-insulin-dependent diabetes undergoing a resistance training program. A double-blind, placebo-controlled, randomized study was carried out with older adults with Type 2 diabetes. Body composition, food intake, muscle strength, glycemic profile, markers of renal function, cardiopulmonary capacity, and quality of life were evaluated. Older adults were randomized into a supplementation group with 33g of WP consumed twice a week on days of resistance training for 12weeks supplemented group and a placebo group. In total, 39 older adults were randomized into two groups, 19 in the supplement group and 20 in the placebo group. Both groups showed improvement in muscle strength, with the WP group failing to exceed that of the control group. WP supplementation slightly increased blood urea compared with the placebo group (p = .05), but values remained within normal limits. The group that used WP showed a small improvement in mental health, according to the 12-Item Short-Form Health Survey questionnaire, but without clinically important improvements. Both groups showed improvements in muscle strength and mass, regardless of supplementation, showing that resistance exercises performed twice a week can contribute to the nonprogression of sarcopenia in older adults with Type 2 diabetes. More studies are needed to determine the safe and effective amount of supplementation to improve muscle strength without renal impairment in older adults with diabetes.

Artificial intelligence in sport: Exploring the potential of using ChatGPT in resistance training prescription.

OpenAI's Chat Generative Pre-trained Transformer (ChatGPT) technology enables conversational interactions with applications across various fields, including sport. Here, ChatGPT's proficiency in designing a 12-week resistance training programme, following specific prompts, was investigated. GPT3.5 and GPT4.0 versions were requested to design 12-week resistance training programmes for male and female hypothetical subjects (20-years-old, no injury, and 'intermediate' resistance training experience). Subsequently, GPT4.0 was requested to design an 'advanced' training programme for the same profiles. The proposed training programmes were compared with established guidelines and literature (e.g., National Strength and Conditioning Association textbook), and discussed. ChatGPT suggested 12-week training programmes comprising three, 4-week phases, each with different objectives (e.g., hypertrophy/strength). GPT3.5 proposed a weekly frequency of ~3 sessions, load intensity of 70-85% of one repetition-maximum, repetition range of 4-8 (2-4 sets), and tempo of 2/0/2 (eccentric/pause/concentric/'pause'). GPT4.0 proposed intermediate- and advanced programme, with a frequency of 5 or 4 sessions, 60-90% or 70-95% intensity, 3-5 sets or 3-6 sets, 5-12 or 3-12 repetitions, respectively. GPT3.5 proposed rest intervals of 90-120 s, and exercise tempo of 2/0/2. GPT4.0 proposed 60-180 (intermediate) or 60-300 s (advanced), with exercise tempo of 2/1/2 for intermediates, and 3/0/1/0, 2/0/1/0, and 1/0/1/0 for advanced programmes. All derived programmes were objectively similar regardless of sex. ChatGPT generated training programmes which likely require additional fine-tuning before application. GPT4.0 synthesised more information than GPT3.5 in response to the prompt, and demonstrated recognition awareness of training experience (intermediate vs advanced). ChatGPT may serve as a complementary tool for writing 'draft' programme, but likely requires human expertise to maximise training programme effectiveness.

Resistance training modalities: comparative analysis of effects on physical fitness, isokinetic muscle functions, and core muscle biomechanics.

This study aimed to evaluate the effects of varied resistance training modalities on physical fitness components, body composition, maximal strength assessed by one-repetition maximum (1RM), isokinetic muscle functions of the shoulder and knee joints, and biomechanical properties of core muscles. Forty participants were randomly assigned to four groups: control group (CG, n = 10), compound set training group (CSG, n = 10), pyramid set training group (PSG, n = 10), and superset training group (SSG, n = 10). Excluding the CG, the other three groups underwent an 8-week resistance training program, three sessions per week, at 60%-80% of 1RM intensity for 60-90min per session. Assessments included body composition, physical fitness components, 1RM, isokinetic muscle functions, and biomechanical properties (muscle frequency, stiffness, etc.) of the rectus abdominis and external oblique muscles. The PSG demonstrated the most significant improvement in relative peak torque during isokinetic testing of the shoulder and knee joints. Compared to the CG, all exercise groups exhibited positive effects on back strength, sprint performance, 1RM, and core muscle biomechanics. Notably, the PSG showed superior enhancement in external oblique stiffness. However, no significant differences were observed among the exercise groups for rectus abdominis biomechanical properties. Structured resistance training effectively improved maximal strength, functional performance, and core muscle biomechanics. The pyramidal training modality conferred specific benefits for isokinetic muscle functions and external oblique stiffness, suggesting its efficacy in enhancing force production capabilities and core stability.

EFFECTS OF TWO DIFFERENT FLYWHEEL RESISTANCE TRAINING PROTOCOLS ON EXPLOSIVE KNEE EXTENSION STRENGTH: A PILOT RANDOMIZED STUDY

The aim of our study was to evaluate differences in explosive isometric knee extension strength adaptations after a flywheel squat resistance training programs performed under low- and high-load conditions. Twenty physically active adults were randomly assigned to an individually allocated high- or low-load eight-week training intervention. Isometric knee extension rate of torque development (RTD) and rate of electromyography signal rise (RER) variables were assessed pre and post eight-week intervention. Statistically significant improvements in the RTD slope variables (100 and 200 ms time intervals after the onset of torque rise; p &lt; 0,05) were observed, regardless of the training load used. Normalized averaged vastus lateralis and rectus femoris electromyography (EMG) amplitude decreased in the intervals 80 ms before, and 75, 100 and 200 ms after the onset of activation (all p &lt; 0,05), regardless of the training group. Our results suggest that high- and low-load resistance flywheel training interventions induce similar increases in explosive knee extension strength, accompanied with a decrease in time-analog normalized EMG signal amplitude.

Resistance Trainings for Enhancement in Jumping Performance: A Comparative Analysis

The primary purpose of programming is to organize training factor modifications that will provide the greatest possible improvement in performance. However, the best programming approach that results in enhanced neuromuscular adaptations is still unclear. This research set out to determine how three varying degrees of unpredictability within resistance training programs affected performance gains. Thirty-six people were split into three groups of twelve each: those who would receive training based on a weekly model (WM), those who would receive instruction based on a daily model (DM), and those who would receive training based on a session model (SM); Six weeks of back squat sessions comprised the training intervention. All participants received the same total training load during the course of six-week intervention. We tested the individual's maximum dynamic strength (1RM) in the back-squat, countermovement jump (CMJ), and squat jump (SJ) both before and after the training intervention. Significant gains were observed across the board (p&lt;0.05). The effect size (ES) of the session model in 1RM is just 0.29. Effect sizes for the daily model and session model in SJ are both moderate, at 0.61 and 0.41 respectively. The impact size in the CMJ daily model is quite moderate (0.51), while it is very large (0.99) in the session model. The results of this study show that changing the type of stimulus used in resistance training more often is a significant way to improve both strength and jumping ability at the same time.

Supplementation with β-hydroxy-β-methylbutyrate after resistance training in post-acute care patients with sarcopenia: A randomized, double-blind placebo-controlled trial

ObjectivesThis study aimed to evaluate the efficacy of adding β-hydroxy-β- methylbutyrate (HMB) supplementation to a 12-week exercise-based rehabilitation program in older adults with sarcopenia after discharge from a post-acute geriatric rehabilitation unit. Study designA randomized, double-blind, placebo-controlled trial with two parallel groups. The intervention group received 3 g/day of Ca-HMB and participated in a 12- week resistance training program (3 sessions/week). The control group received a placebo and followed the same training program. Main outcome measuresThe primary outcomes were the improvements of handgrip strength and physical performance assessed through the Short Physical Performance Battery (SPPB) and 4-meter gait speed; and handgrip strength. All variables were assessed at baseline, post-intervention, and 1-year follow-up. ResultsAfter completing the 12-week exercise program, the intervention group showed significant improvements in SPPB-Balance (1.3, 95 %CI 0.3 to 2.4) and total SPPB score (2.2, 95 %CI 0.4 to 4.0). Intra-group analysis demonstrated gains in the SPPB-Chair Stand (0.7 points, 95 %CI 0.0 to 1.4) and total SPPB score (2.1 points, 95 %CI 0.3 to 3.9) in the intervention group. Improvements in handgrip strength were observed in women (3.7 kg, 95 %CI: 0.2 to 7.3) at the end of the intervention, and persisted at the 1-year follow-up. ConclusionsOur findings suggest that the supplementation of 3 g/day of Ca-HMB with resistance exercise may significantly enhance muscle strength and physical performance among older women with sarcopenia after recent hospitalization. Given this study's limitations, the intervention's effectiveness cannot be drawn, and further studies are needed.

OLDER US ADULTS PREFER SHORT, FREQUENT RESISTANCE TRAINING PROGRAMS, ESPECIALLY THOSE WITH DIFFICULTY WALKING

Abstract Though resistance training (RT) improves strength and physical function, fewer than 20% of older adults do RT at least twice weekly, as recommended by national guidelines. Even when programs are free, such as Silver Sneakers, fewer than 25% participate and those that do rarely attend (averaging &amp;lt; 20 visits/year). Many individuals cite “lack of time” as the primary reason for not attending. Therefore, one approach to increase participation in RT programs could be making sessions shorter. However, little is known about older adult RT program preferences. Therefore, we conducted a nationwide survey among 611 US adults aged 65 and over. We compared their interest in a traditional (45 minutes, three days/week) RT program to a shorter, more frequent (5-minute, every day) RT program. Overall, 2.2 times as many older adults preferred the shorter vs. the traditional RT program (68.4% v. 31.6%; p&amp;lt; 0.001). Furthermore, barrier self-efficacy for the shorter program was 50% greater than the traditional program. Adults with health concerns, like poorer self-rated health and a history of falls, were significantly more likely to be interested in the shorter program. Notably, 87% of older adults with difficulty walking also preferred the shorter program. These findings suggest strong interest in short RT programs among older adults, especially those with poorer health and mobility disabilities for whom traditional RT programs may be too challenging. Reducing the duration of RT programs may be an appealing option to engage older adults in RT, particularly among those for whom the program would provide the most benefit.

EVALUATION OF ONLINE AEROBIC TRAINING AND RESISTANCE TRAINING IN OLDER ADULTS WITH MCI: A THREE-ARM RCT

Abstract This study aimed to evaluate the effects of online aerobic and resistance training programs in community-dwelling older adults with mild cognitive impairment. A total of 108 participants (60~87 years) were recruited, and equally randomized to aerobic group (3-5 times/week, 30-50min/section), resistance group (2 times/week, 5 to 6 exercises/section), or control group. Cognitive functions were evaluated at baseline, the 13rd week (T1) and 26th week (T2). Effects were evaluated by linear mixed effects model (LME) after controlling for covariates. Inter-individual differences on the cognitive effects were explored. After six-month intervention, 15 (13.89%) participants dropped out, and the median compliance rates were 80.77% for aerobic group and 96.15 for resistance group. LME revealed that ADAs-cog scores in aerobic group decreased by 2.14 at T1 and 1.68 at T2 more than the control group. And the ADAs-cog scores in resistance group decreased by1.43 more than the control group at T1. For executive function, the Stroop time interference in resistance group at T2 declined 11.12 seconds more than the control group, and 13.85 seconds more than the aerobic group. For memory performance, the RAVLT scores at T1 in aerobic group tended to increase 5.15 (p = 0.065) more than the control group. There existed true inter-individual differences in the responses to exercise. Compliance rates, social activity participation, cognitive function and physical function at baseline were the significant factors. Overall, our study confirmed the positive effects of both aerobic and resistance exercise on global cognition, while their effects on specific cognitive domains were different.

IMPACT OF A 4-MINUTE STRENGTH TRAINING PROGRAM ON LOWER BODY FUNCTION IN OLDER ADULTS WITH MOBILITY DISABILITY

Abstract One in four older adults experience mobility disability, often resulting in financial strain and declines in quality of life. Though resistance training (RT) can improve physical function, too few older adults do RT. This study specifically reports on the impact of a short, daily RT program called Functional Activity Strength Training (FAST) on lower extremity function. FAST entailed one 30-second bout each of four exercises (push-ups, chair stands, two-arm resistance band rows, stair-stepping) followed by 30 seconds of rest daily for 12 weeks. Ninety-seven participants were randomly assigned to either intervention (n = 44) or delayed treatment control (n = 53) group. Research staff remotely provided one-on-one coaching relating to modifications and progress every 2 weeks until week 8. Participants received a daily email reminder to complete the exercises and report repetitions completed for each exercise. Outcome measures (5-time sit-to-stand, maximum 30 second chair stand performance, and single-leg stance duration) were evaluated at baseline and week 12. Participants completed exercises on 80% of possible days. Over the 12 weeks, the intervention group improved over and above the control group by +4.2 chair stands (d = 1.21), -2.3 seconds (d = -0.43) on the 5-times sit-to-stand, and +3.58 seconds (d = 0.46) on the single-leg stance. In sum, a four-minute daily, 12-week functional RT program led to improvements in chair stand, 5-times sit-to-stand, and single-leg stance performance. Efficacy trials, using gold-standard assessments should examine whether similar improvements are observed and adherence is maintained over a longer period of time.

The Influence of Unstable Load and Traditional Free-Weight Back Squat Exercise on Subsequent Countermovement Jump Performance.

The purpose of the present study was to examine the effects of a back squat exercise with unstable load (UN) and traditional free-weight resistance (FWR) on subsequent countermovement jump (CMJ) performance. After familiarisation, thirteen physically active males with experience in resistance training visited the laboratory on two occasions during either experimental (UN) or control (FWR) conditions separated by at least 72 h. In both sessions, participants completed a task-specific warm-up routine followed by three maximum CMJs (pre-intervention; baseline) and a set of three repetitions of either UN or FWR back squat exercise at 85% 1-RM. During the UN condition, the unstable load was suspended from the bar with elastic bands and accounted for 15% of the total load. Post-intervention, three maximum CMJs were performed at 30 s, 4 min, 8 min and 12 min after the last repetition of the intervention. The highest CMJ for each participant was identified for each timepoint. No significant increases (p > 0.05) in jump height, peak concentric power, or peak rate of force development (RFD) were found after the FWR or UN conditions at any timepoint. The lack of improvements following both FWR and UN conditions may be a consequence of the low percentage of unstable load and the inclusion of a comprehensive task-specific warm-up. Further research is required to explore higher UN load percentages (>15%) and the chronic effects following the implementation of a resistance training programme.

Moderators of Resistance Training Effects in Healthy Young Women: A Systematic Review and Meta-analysis.

Molinari, T, Radaelli, R, Rech, A, Brusco, CM, Markarian, AM, and Lopez, P. Moderators of resistance training effects in healthy young women: A systematic review and meta-analysis. J Strength Cond Res 38(4): 804-814, 2024-To systematically review and analyze the effects of resistance-based exercise programs and potential moderators of change in body fat percentage, whole-body fat and lean mass, muscle hypertrophy, muscle strength, and muscle power/rapid force in healthy young women (between 18 and 35 years). A systematic search was undertaken in 7 databases from inception to May 2022. Eligible randomized controlled trials examined the effects of resistance-based exercise programs on outcomes of interest in healthy young women. Meta-analysis was undertaken with a 3-level mixed-effects model. Associations between standardized mean difference (SMD) and potential moderators (number of sessions, weekly volume, and intensity) were tested by meta-regression models. Statistical significance was set at an α level of 0.05, whereas an α level of 0.05-0.10 was also considered for potential moderators of resistance training effects. Forty articles ( n = 1,312) were included. Resistance-based exercise programs resulted in a significant improvement of 0.4 SMD (95% confidence intervals [95% CI]: 0.2 to 0.5, p < 0.001) in lean mass/muscle hypertrophy and 1.2 SMD (95% CI: 0.9 to 1.5, p < 0.001) in muscle strength. A higher number of sessions was associated with changes in lean mass/muscle hypertrophy ( β = 0.01 ± 0.00, p = 0.009), whereas a higher weekly volume approached statistical significance to moderate changes in muscle strength ( β = 0.01 ± 0.01, p = 0.053). Body fat percentage (-0.4 SMD, 95% CI: -0.6 to -0.1, p = 0.006) and muscle power/rapid force (0.6 SMD, 95% CI: 0.2 to 1.1, p = 0.011) were significantly improved. In conclusion, a higher resistance training volume was associated with greater improvements in lean mass/muscle hypertrophy, muscle strength, and body fat percentage, whereas muscle power/rapid force improvements were observed irrespective of prescription characteristics. These findings may help in designing resistance training programs for muscle hypertrophy, strength and power, and body fat percentage in healthy women.

Effects of Two Different Low-Volume Resistance Training Programs Applied During the Off-Season Period on the Speed-Power Performance of Elite Youth Soccer Players.

Loturco, I, Nunes, RFH, Lampert, RR, Silva, RLP, Hespanhol, JE, Novack, LF, Conde, JHS, Pereira, LA, and McGuigan, MR. Effects of two different low-volume resistance training programs applied during the off-season period on the speed-power performance of elite youth soccer players. . J Strength Cond Res 38(3): 571-576, 2024-The aim of this study was to analyze the changes in the speed-power performance of elite youth soccer players submitted to 2 different low-volume resistance training programs during the off-season period. Twenty under-17 players were randomly allocated to "traditional nonballistic" or "ballistic training" groups. Countermovement jump (CMJ), 20-m sprinting speed, and half-squat (HS) power tests were performed after the final match of the season (pretesting session) and at the beginning of the subsequent season (post-testing session), after 4 weeks of detraining. Between-group differences were assessed using a 2-way ANOVA with repeated measures followed by the Tukey's post hoc test. Performance variations were individually analyzed with the use of the "true changes" calculation. At post-tests, CMJ height and HS power remained unchanged ( p > 0.05) but similar and significant improvements in sprint speed were observed in both groups ( p < 0.05). However, notably, a larger number of players in the ballistic group exhibited "true changes" in HS power (i.e., 55 vs. 33%, compared with the traditional group, respectively). In conclusion, either low-volume ballistic or traditional resistance training schemes were able to increase sprint speed and maintain power output during a short interseason break in youth soccer players. Despite this apparent similarity, at the individual level, ballistic movements were more efficient at improving lower-body power. Practitioners can use the strategies described here to improve the sprint and power performance of soccer players during short periods of soccer-specific training cessation.

Effect of resistance training programs differing in set structure on muscular hypertrophy and performance in untrained young men.

Purpose: This study aimed to compare the effects on muscle hypertrophy and muscular performance of two resistance training (RT) programs that differed only in set structure: traditional set structure (TS) vs. rest redistribution set structure (RR). Methods: Thirty untrained young men were pair-matched and randomly assigned to a TS (n = 15) or an RR (n = 15) protocol based on individual baseline measures. Participants trained for 8weeks using the same total body RT routines performed twice weekly. The TS protocol comprised four sets of 10 repetitions per exercise with 120-s interset rest, and the RR involved eight sets of five repetitions per exercise with 51-s interset rest. Participants were tested pre- and post-intervention for body composition, regional muscle thickness, upper- and lower-body muscle maximal strength [1-repetition maximum (1RM)], mean power output and velocity at 75% 1RM and muscular endurance (repetitions to failure at 70% 1RM). Results: Compared to baseline, both groups exhibited equally significantly decreased body fat mass (p < 0.05), increased fat-free mass (p < 0.001), muscle thickness (p < 0.05), upper and lower-body muscular maximal strength (p < 0.001) and endurance performance (p < 0.001). However, both groups only increase the lower-body power output (p < 0.001) but not the upper-body (p > 0.05). No significant differences existed between groups for all measurements (p > 0.05). Conclusion: These results suggest that RR and TS groups have similar effects for improving muscle hypertrophy and performance in untrained young men.