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Creatine Supplementation and Upper Limb Strength Performance: A Systematic Review and Meta-Analysis.Sports Medicine (Auckland, N.Z.) Jan 2017Creatine is the most widely used supplementation to increase performance in strength; however, the most recent meta-analysis focused specifically on supplementation... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Creatine is the most widely used supplementation to increase performance in strength; however, the most recent meta-analysis focused specifically on supplementation responses in muscles of the lower limbs without regard to upper limbs.
OBJECTIVE
We aimed to systematically review the effect of creatine supplementation on upper limb strength performance.
METHODS
We conducted a systematic review and meta-analyses of all randomized controlled trials comparing creatine supplementation with a placebo, with strength performance measured in exercises shorter than 3 min in duration. The search strategy used the keywords 'creatine', 'supplementation', and 'performance'. Independent variables were age, sex and level of physical activity at baseline, while dependent variables were creatine loading, total dose, duration, time interval between baseline (T0) and the end of the supplementation (T1), and any training during supplementation. We conducted three meta-analyses: at T0 and T1, and on changes between T0 and T1. Each meta-analysis was stratified within upper limb muscle groups.
RESULTS
We included 53 studies (563 individuals in the creatine supplementation group and 575 controls). Results did not differ at T0, while, at T1, the effect size (ES) for bench press and chest press were 0.265 (95 % CI 0.132-0.398; p < 0.001) and 0.677 (95 % CI 0.149-1.206; p = 0.012), respectively. Overall, pectoral ES was 0.289 (95 % CI 0.160-0.419; p = 0.000), and global upper limb ES was 0.317 (95 % CI 0.185-0.449; p < 0.001). Meta-analysis of changes between T0 and T1 gave similar results. The meta-regression showed no link with characteristics of population or supplementation, demonstrating the efficacy of creatine independently of all listed conditions.
CONCLUSION
Creatine supplementation is effective in upper limb strength performance for exercise with a duration of less than 3 min, independent of population characteristics, training protocols, and supplementary doses or duration.
Topics: Creatine; Dietary Supplements; Humans; Lower Extremity; Muscle Strength; Muscle, Skeletal; Randomized Controlled Trials as Topic; Upper Extremity
PubMed: 27328852
DOI: 10.1007/s40279-016-0571-4 -
Journal of the American Medical... May 2022This study aimed to determine the comparative effectiveness of interventions in treatment of sarcopenia. The primary outcome was the measure of treatment effect on... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
This study aimed to determine the comparative effectiveness of interventions in treatment of sarcopenia. The primary outcome was the measure of treatment effect on muscle mass, and secondary outcomes were the treatment effect on muscle strength and physical performance.
DESIGN
Systematic review and network meta-analysis (NMA).
SETTING AND PARTICIPANTS
Participants with sarcopenia receiving interventions targeting sarcopenia in any setting.
METHODS
Data sources: Relevant RCTs were identified by a systematic search of several electronic databases, including CINAHL, Embase, MEDLINE, and the Cochrane Central Registry of Controlled Trials (CENTRAL) from January 1995 to July 2019. Duplicate title and abstract and full-text screening, data extraction, and risk of bias assessment were performed.
DATA EXTRACTION
All RCTs examining sarcopenia interventions [mixed exercise (combined aerobic and resistance exercise), aerobic exercise, resistance exercise, balance exercise, physical activity and protein or nutrition supplementation, acupuncture, whole-body vibration, protein supplement or interventions to increase protein intake, any nutritional intervention other than protein, and pharmacotherapy] were included. Comparators were standard care, placebo, or another intervention.
DATA SYNTHESIS
We performed Bayesian NMA; continuous outcome data were pooled using the standardized mean difference effect size. Interventions were ranked using the surface under the cumulative ranking curve (SUCRA) for each outcome.
RESULTS
A total of 59 RCTs were included after screening of 4315 citations and 313 full-text articles. Network meta-analysis of muscle mass outcome (including 46 RCTs, 3649 participants, 11 interventions) suggested that mixed exercise were the most effective intervention (SUCRA = 93.94%) to increase muscle mass. Physical activity and protein or nutrition supplementation, and aerobic exercise were the most effective interventions to improve muscle strength and physical performance, respectively. Overall, mixed exercise is the most effective intervention in increasing muscle mass and was one of the 3 most effective interventions in increasing muscle strength and physical performance.
CONCLUSIONS AND IMPLICATIONS
Mixed exercise and physical activity with nutritional supplementation are the most effective sarcopenia interventions. Most of the included studies have a high risk of bias. More robust RCTs are needed to increase the confidence of our NMA results and the quality of evidence.
Topics: Bayes Theorem; Humans; Muscle Strength; Network Meta-Analysis; Randomized Controlled Trials as Topic; Sarcopenia
PubMed: 35183490
DOI: 10.1016/j.jamda.2022.01.057 -
The Journal of Sports Medicine and... Aug 2022The aim of this study was to compare changes in muscle size, strength, and power between free-weight and machine-based exercises. (Meta-Analysis)
Meta-Analysis
INTRODUCTION
The aim of this study was to compare changes in muscle size, strength, and power between free-weight and machine-based exercises.
EVIDENCE ACQUISITION
The online databases of Pubmed, Scopus, and Web of Science were each searched using the following terms: "free weights" OR barbells OR dumbbells AND machines" up until September 15, 2020. A three-level random effects meta-analytic model was used to compute effect sizes.
EVIDENCE SYNTHESIS
When strength was tested using a free-weight exercise, individuals training with free-weights gained more strength than those training with machines (ES: 0.655; [95% CI: 0.269, 1.041]). When strength was tested a machine-based exercise incorporated as part of the machine-based training program, individuals training with machines gained more strength than those training with free-weights (ES: -0.784 [95% CI: -1.223, -0.344]). When strength was tested using a neutral device, machines and free-weight exercises resulted in similar strength gains (ES: 0.128 [95% CI: -0303, 0.559]). There were no differences in the change in power (ES: -0.049 [95% CI: -0.557, 0.460]) or muscle hypertrophy (ES: -0.01 [95% CI: -0.525, 0.545]) between exercise modes.
CONCLUSIONS
Individuals looking to increase strength and power should consider the specificity of exercise, and how their strength and power will be tested and applied. Individuals looking to increase general strength and muscle mass to maintain health may choose whichever activity they prefer and are more likely to adhere to.
Topics: Exercise; Exercise Therapy; Humans; Muscle Strength; Muscle, Skeletal; Resistance Training
PubMed: 34609100
DOI: 10.23736/S0022-4707.21.12929-9 -
European Journal of Sport Science Feb 2021The objectives of this paper were to: (a) systematically review studies that explored the effects of exercise order (EO) on muscular strength and/or hypertrophy; (b)... (Meta-Analysis)
Meta-Analysis
The objectives of this paper were to: (a) systematically review studies that explored the effects of exercise order (EO) on muscular strength and/or hypertrophy; (b) pool their results using a meta-analysis; and (c) provide recommendations for the prescription of EO in resistance training (RT) programmes. A literature search was performed in four databases. Studies were included if they explored the effects of EO on dynamic muscular strength and/or muscle hypertrophy. The meta-analysis was performed using a random-effects model with Hedges' g effect size (ES). The methodological quality of studies was appraised using the TESTEX checklist. Eleven good-to-excellent methodological quality studies were included in the review. When all strength tests, that is, both in multi-joint (MJ) and single-joint (SJ) exercises were considered, there was no difference between the EOs (ES = -0.11; 0.306). However, there was a difference between the MJ-to-SJ and SJ-to-MJ orders for strength gains in the MJ exercises, favouring starting the exercise session with MJ exercises (ES = 0.32; 0.034), and the strength gains in the SJ exercises, favouring starting the exercise session with SJ exercises (ES = -0.58; 0.032). No significant effect of EO was observed for hypertrophy combining site-specific and indirect measures (ES = 0.03; 0.862). In conclusion, increases in muscular strength are the largest in the exercises performed at the beginning of an exercise session. For muscle hypertrophy, our meta-analysis indicated that both MJ-to-SJ and SJ-to-MJ EOs may produce similar results.
Topics: Humans; Hypertrophy; Muscle Strength; Muscle, Skeletal; Resistance Training
PubMed: 32077380
DOI: 10.1080/17461391.2020.1733672 -
Nutrients Feb 2021Although animal protein is usually considered to be a more potent stimulator of muscle protein synthesis than plant protein, the effect of protein source on lean mass... (Meta-Analysis)
Meta-Analysis
Although animal protein is usually considered to be a more potent stimulator of muscle protein synthesis than plant protein, the effect of protein source on lean mass and muscle strength needs to be systematically reviewed. This study aimed to examine potential differences in the effect of animal vs. plant protein on lean mass and muscle strength, and the possible influence of resistance exercise training (RET) and age. The following databases were searched: PubMed, Embase, Scopus and CINAHL Plus with Full Text, and 3081 articles were screened. A total of 18 articles were selected for systematic review, of which, 16 were used for meta-analysis. Total protein intakes were generally above the recommended dietary allowance at the baseline and end of intervention. Results from the meta-analyses demonstrated that protein source did not affect changes in absolute lean mass or muscle strength. However, there was a favoring effect of animal protein on percent lean mass. RET had no influence on the results, while younger adults (<50 years) were found to gain absolute and percent lean mass with animal protein intake (weighted mean difference (WMD), 0.41 kg; 95% confidence interval (CI) 0.08 to 0.74; WMD 0.50%; 95% CI 0.00 to 1.01). Collectively, animal protein tends to be more beneficial for lean mass than plant protein, especially in younger adults.
Topics: Adult; Age Factors; Aged; Animal Proteins, Dietary; Female; Humans; Male; Middle Aged; Muscle Strength; Muscle, Skeletal; Nutritional Physiological Phenomena; Plant Proteins, Dietary; Randomized Controlled Trials as Topic; Resistance Training
PubMed: 33670701
DOI: 10.3390/nu13020661 -
British Journal of Sports Medicine Aug 2021We systemically reviewed the literature to assess how long-term testosterone suppressing gender-affirming hormone therapy influenced lean body mass (LBM), muscular area,...
How does hormone transition in transgender women change body composition, muscle strength and haemoglobin? Systematic review with a focus on the implications for sport participation.
OBJECTIVES
We systemically reviewed the literature to assess how long-term testosterone suppressing gender-affirming hormone therapy influenced lean body mass (LBM), muscular area, muscular strength and haemoglobin (Hgb)/haematocrit (HCT).
DESIGN
Systematic review.
DATA SOURCES
Four databases (BioMed Central, PubMed, Scopus and Web of Science) were searched in April 2020 for papers from 1999 to 2020.
ELIGIBILITY CRITERIA FOR SELECTING STUDIES
Eligible studies were those that measured at least one of the variables of interest, included transwomen and were written in English.
RESULTS
Twenty-four studies were identified and reviewed. Transwomen experienced significant decreases in all parameters measured, with different time courses noted. After 4 months of hormone therapy, transwomen have Hgb/HCT levels equivalent to those of cisgender women. After 12 months of hormone therapy, significant decreases in measures of strength, LBM and muscle area are observed. The effects of longer duration therapy (36 months) in eliciting further decrements in these measures are unclear due to paucity of data. Notwithstanding, values for strength, LBM and muscle area in transwomen remain above those of cisgender women, even after 36 months of hormone therapy.
CONCLUSION
In transwomen, hormone therapy rapidly reduces Hgb to levels seen in cisgender women. In contrast, hormone therapy decreases strength, LBM and muscle area, yet values remain above that observed in cisgender women, even after 36 months. These findings suggest that strength may be well preserved in transwomen during the first 3 years of hormone therapy.
Topics: Adipose Tissue; Androgen Antagonists; Athletic Performance; Body Composition; Cyproterone Acetate; Estradiol; Female; Hematocrit; Hemoglobin A; Humans; Male; Muscle Strength; Muscle, Skeletal; Sports; Testosterone; Time Factors; Transgender Persons; Transsexualism
PubMed: 33648944
DOI: 10.1136/bjsports-2020-103106 -
Nutrients Oct 2021Sarcopenia refers to the age-related loss of muscle strength and muscle mass, which is associated with a reduced quality of life, particularly in older females.... (Meta-Analysis)
Meta-Analysis
Sarcopenia refers to the age-related loss of muscle strength and muscle mass, which is associated with a reduced quality of life, particularly in older females. Resistance training (RT) is well established to be an effective intervention to counter indices of sarcopenia. Accumulating research indicates that the addition of creatine supplementation (Cr) to RT augments gains in muscle strength and muscle mass, compared to RT alone. However, some evidence indicates that sex differences may alter the effectiveness of Cr. Therefore, we systematically reviewed randomized controlled trials (RCTs) investigating the efficacy of Cr + RT on measures of upper- and lower-body strength and muscle mass in older females. A systematic literature search was performed in nine electronic databases. Ten RCTs ( = 211 participants) were included the review. Overall, Cr significantly increased measures of upper-body strength (7 studies, = 142, = 0.04), with no effect on lower-body strength or measures of muscle mass. Sub-analyses revealed that both upper-body (4 studies, = 97, = 0.05) and lower-body strength (4 studies, = 100, = 0.03) were increased by Cr, compared to placebo in studies ≥ 24 weeks in duration. In conclusion, older females supplementing with Cr experience significant gains in muscle strength, especially when RT lasts for at least 24 weeks in duration. However, given the level of evidence, future high-quality studies are needed to confirm these findings.
Topics: Aged; Aged, 80 and over; Creatine; Dietary Supplements; Elder Nutritional Physiological Phenomena; Female; Humans; Muscle Strength; Muscle, Skeletal; Randomized Controlled Trials as Topic; Resistance Training; Sarcopenia; Treatment Outcome
PubMed: 34836013
DOI: 10.3390/nu13113757 -
Sports Medicine (Auckland, N.Z.) May 2017Resistance training is an integral component of physical preparation for athletes. A growing body of evidence indicates that eccentric strength training methods induce... (Review)
Review
BACKGROUND
Resistance training is an integral component of physical preparation for athletes. A growing body of evidence indicates that eccentric strength training methods induce novel stimuli for neuromuscular adaptations.
OBJECTIVE
The purpose of this systematic review was to determine the effects of eccentric training in comparison to concentric-only or traditional (i.e. constrained by concentric strength) resistance training.
METHODS
Searches were performed using the electronic databases MEDLINE via EBSCO, PubMed and SPORTDiscus via EBSCO. Full journal articles investigating the long-term (≥4 weeks) effects of eccentric training in healthy (absence of injury or illness during the 4 weeks preceding the training intervention), adult (17-35 years), human participants were selected for the systematic review. A total of 40 studies conformed to these criteria.
RESULTS
Eccentric training elicits greater improvements in muscle strength, although in a largely mode-specific manner. Superior enhancements in power and stretch-shortening cycle (SSC) function have also been reported. Eccentric training is at least as effective as other modalities in increasing muscle cross-sectional area (CSA), while the pattern of hypertrophy appears nuanced and increased CSA may occur longitudinally within muscle (i.e. the addition of sarcomeres in series). There appears to be a preferential increase in the size of type II muscle fibres and the potential to exert a unique effect upon fibre type transitions. Qualitative and quantitative changes in tendon tissue that may be related to the magnitude of strain imposed have also been reported with eccentric training.
CONCLUSIONS
Eccentric training is a potent stimulus for enhancements in muscle mechanical function, and muscle-tendon unit (MTU) morphological and architectural adaptations. The inclusion of eccentric loads not constrained by concentric strength appears to be superior to traditional resistance training in improving variables associated with strength, power and speed performance.
Topics: Adaptation, Physiological; Adolescent; Adult; Exercise; Humans; Muscle Contraction; Muscle Fibers, Skeletal; Muscle Strength; Muscle, Skeletal; Physical Education and Training; Resistance Training
PubMed: 27647157
DOI: 10.1007/s40279-016-0628-4 -
Journal of the American Medical... Aug 2023This systematic review aims to reevaluate the role of minerals on muscle mass, muscle strength, physical performance, and the prevalence of sarcopenia in... (Review)
Review
OBJECTIVE
This systematic review aims to reevaluate the role of minerals on muscle mass, muscle strength, physical performance, and the prevalence of sarcopenia in community-dwelling and institutionalized older adults.
DESIGN
Systematic review.
SETTING AND PARTICIPANTS
In March 2022, a systematic search was performed in PubMed, Scopus, and Web of Sciences using predefined search terms. Original studies on dietary mineral intake or mineral serum blood concentrations on muscle mass, muscle strength, and physical performance or the prevalence of sarcopenia in older adults (average age ≥65 years) were included.
METHODS
Eligibility screening and data extraction was performed by 2 independent reviewers. Quality assessment was performed with the Effective Public Health Practice Project (EPHPP) Quality Assessment Tool for Quantitative Studies. Risk of bias was evaluated using the Risk Of Bias In Non-randomized Studies-of Exposure (ROBINS-E) tool.
RESULTS
From the 15,622 identified articles, a total of 45 studies were included in the review, mainly being cross-sectional and observational studies. Moderate quality of evidence showed that selenium (n = 8) and magnesium (n = 7) were significantly associated with muscle mass, strength, and physical performance as well as the prevalence of sarcopenia. For calcium and zinc, no association could be found. For potassium, iron, sodium, and phosphorus, the association with sarcopenic outcomes remains unclear as not enough studies could be included or were nonconclusive (low quality of evidence).
CONCLUSIONS AND IMPLICATIONS
This systematic review shows a potential role for selenium and magnesium on the prevention and treatment of sarcopenia in older adults. More randomized controlled trials are warranted to determine the impact of minerals on sarcopenia in older adults.
Topics: Humans; Aged; Sarcopenia; Magnesium; Selenium; Cross-Sectional Studies; Muscle Strength
PubMed: 37355247
DOI: 10.1016/j.jamda.2023.05.017 -
Sports Medicine (Auckland, N.Z.) Mar 2023The current literature on the chronic effects of static stretching (SS) exercises on muscle strength and power is unclear and controversial. (Meta-Analysis)
Meta-Analysis
Chronic Effects of Static Stretching Exercises on Muscle Strength and Power in Healthy Individuals Across the Lifespan: A Systematic Review with Multi-level Meta-analysis.
BACKGROUND
The current literature on the chronic effects of static stretching (SS) exercises on muscle strength and power is unclear and controversial.
OBJECTIVE
We aimed to examine the chronic effects of SS exercises on muscle strength and power as well as flexibility in healthy individuals across the lifespan.
DESIGN
Systematic review with meta-analysis of (randomized) controlled trials.
DATA SOURCES
A systematic literature search was conducted in the databases PubMed, Web of Science, Cochrane Library, and SPORTDiscus up to May 2022.
ELIGIBILITY CRITERIA FOR SELECTING STUDIES
We included studies that investigated the chronic effects of SS exercises on at least one muscle strength and power outcome compared to an active/passive control group or the contralateral leg (i.e., using between- or within-study designs, respectively) in healthy individuals, irrespective of age, sex, and training status.
RESULTS
The main findings of 41 studies indicated trivial-to-small positive effects of chronic SS exercises on muscle strength (standardized mean difference [SMD] = 0.21, [95% confidence interval 0.10-0.32], p = 0.001) and power (SMD = 0.19, 95% confidence interval 0.12-0.26], p < 0.001). For flexibility, moderate-to-large increases were observed (SMD = 0.96, [95% confidence interval 0.70-1.22], p < 0.001). Subgroup analyses, taking the participants' training status into account, revealed a larger muscle strength improvement for sedentary (SMD = 0.58, p < 0.001) compared with recreationally active participants (SMD = 0.16, p = 0.029). Additionally, larger flexibility gains were observed following passive (SMD = 0.97, p < 0.001) compared with active SS exercises (SMD = 0.59, p = 0.001). The chronic effects of SS on muscle strength were moderated by the proportion of female individuals in the sample (β = 0.004, p = 0.042), with higher proportions experiencing larger gains. Other moderating variables included mean age (β = 0.011, p < 0.001), with older individuals showing larger muscle strength gains, and the number of repetitions per stretching exercise and session (β = 0.023, p = 0.004 and β = 0.013, p = 0.008, respectively), with more repetitions associated with larger muscle strength improvements. Muscle power was also moderated by mean age (β = 0.006, p = 0.007) with larger gains in older individuals. The meta-regression analysis indicated larger flexibility gains with more repetitions per session (β = 0.094, p = 0.016), more time under stretching per session (β = 0.090, p = 0.026), and more total time under stretching (β = 0.078, p = 0.034).
CONCLUSIONS
The main findings indicated that chronic SS exercises have the potential to improve muscle strength and power. Such improvements appear to benefit sedentary more than recreationally active participants. Likewise, chronic SS exercises result in a marked enhancement in flexibility with larger effects of passive, as compared with active, SS. The results of the meta-regression analysis for muscle strength indicated larger benefits of chronic SS exercises in samples with higher proportions of female, older participants, and a higher number of repetitions per stretching exercise and session. For muscle power, results suggested larger gains for older participants. Regarding flexibility, findings indicated larger benefits following a higher number of repetitions per exercise and a longer time under stretching per session as well as a longer total time under stretching.
Topics: Humans; Female; Aged; Muscle Stretching Exercises; Longevity; Muscle Strength; Resistance Training
PubMed: 36719536
DOI: 10.1007/s40279-022-01806-9