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Sports Medicine (Auckland, N.Z.) Dec 2015It has frequently been reported that balance and lower-extremity muscle strength/power are associated with sports-related and everyday activities. Knowledge about the... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
It has frequently been reported that balance and lower-extremity muscle strength/power are associated with sports-related and everyday activities. Knowledge about the relationship between balance, strength, and power are important for the identification of at-risk individuals because deficits in these neuromuscular components are associated with an increased risk of sustaining injuries and falls. In addition, this knowledge is of high relevance for the development of specifically tailored health and skill-related exercise programs.
OBJECTIVES
The objectives of this systematic literature review and meta-analysis were to characterize and, if possible, quantify associations between variables of balance and lower-extremity muscle strength/power in healthy individuals across the lifespan.
DATA SOURCES
A computerized systematic literature search was performed in the electronic databases PubMed, Web of Science, and SPORTDiscus up to March 2015 to capture all relevant articles.
STUDY ELIGIBILITY CRITERIA
A systematic approach was used to evaluate the 996 articles identified for initial review. Studies were included only if they investigated healthy individuals aged ≥6 years and tested at least one measure of static steady-state balance (e.g., center of pressure [CoP] displacement during one-legged stance), dynamic steady-state balance (e.g., gait speed), proactive balance (e.g., distance in the functional-reach-test), or reactive balance (e.g., CoP displacement during perturbed one-legged stance), and one measure of maximal strength (e.g., maximum voluntary contraction), explosive force (e.g., rate of force development), or muscle power (e.g., jump height). In total, 37 studies met the inclusionary criteria for review.
STUDY APPRAISAL AND SYNTHESIS METHODS
The included studies were coded for the following criteria: age (i.e., children: 6-12 years, adolescents: 13-18 years, young adults: 19-44 years, middle-aged adults: 45-64 years, old adults: ≥65 years), sex (i.e., female, male), and test modality/outcome (i.e., test for the assessment of balance, strength, and power). Studies with athletes, patients, and/or people with diseases were excluded. Pearson's correlation coefficients were extracted, transformed (i.e., Fisher's z-transformed r z value), aggregated (i.e., weighted mean r z value), back-transformed to r values, classified according to their magnitude (i.e., small: r ≤ 0.69, medium: r ≤ 0.89, large: r ≥ 0.90), and, if possible, statistically compared. Heterogeneity between studies was assessed using I2 and Chi-squared (χ2) statistics.
RESULTS
Three studies examined associations between balance and lower-extremity muscle strength/power in children, one study in adolescents, nine studies in young adults, three studies in middle-aged adults, and 23 studies in old adults. Overall, small-sized associations were found between variables of balance and lower-extremity muscle strength/power, irrespective of the age group considered. In addition, small-sized but significantly larger correlation coefficients were found between measures of dynamic steady-state balance and maximal strength in children (r = 0.57) compared with young (r = 0.09, z = 3.30, p = 0.001) and old adults (r = 0.35, z = 2.94, p = 0.002) as well as in old compared with young adults (z = 1.95, p = 0.03).
LIMITATIONS
Even though the reported results provided further insight into the associations between measures of balance and lower-extremity muscle strength/power, they did not allow us to deduce cause and effect relations. Further, the investigated associations could be biased by other variables such as joint flexibility, muscle mass, and/or auditory/visual acuity.
CONCLUSIONS
Our systematic review and meta-analysis showed predominately small-sized correlations between measures of balance and lower-extremity muscle strength/power in children, adolescents, and young, middle-aged, and old adults. This indicates that these neuromuscular components are independent of each other and should therefore be tested and trained complementarily across the lifespan. Significantly larger but still small-sized associations were found between measures of dynamic steady-state balance and maximal strength in children compared with young and old adults as well as in old compared with young adults. These findings imply that age/maturation may have an impact on the association of selected components of balance and lower-extremity muscle strength.
Topics: Adolescent; Adult; Aged; Aging; Child; Exercise; Female; Humans; Lower Extremity; Male; Middle Aged; Muscle Strength; Physical Fitness; Postural Balance; Young Adult
PubMed: 26412212
DOI: 10.1007/s40279-015-0390-z -
Journal of Cachexia, Sarcopenia and... Jun 2023Sarcopenia is a serious public health concern among older adults worldwide. Exercise is the most common intervention for sarcopenia. This study aimed to compare the... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Sarcopenia is a serious public health concern among older adults worldwide. Exercise is the most common intervention for sarcopenia. This study aimed to compare the effectiveness of different exercise types for older adults with sarcopenia.
METHODS
Randomized controlled trials (RCTs) that examined the effectiveness of exercise interventions on patient-important outcomes for older adults with sarcopenia were eligible. We systematically searched MEDLINE, Embase and Cochrane Central Register of Controlled Trials via Ovid until 3 June 2022. We used frequentist random-effects network meta-analyses to summarize the evidence and applied the Grading of Recommendations, Assessment, Development, and Evaluations framework to rate the certainty of evidence.
RESULTS
Our search identified 5988 citations, of which 42 RCTs proved eligible with 3728 participants with sarcopenia (median age: 72.9 years, female: 73.3%) with a median follow-up of 12 weeks. We are interested in patient-important outcomes that include mortality, quality of life, muscle strength and physical function measures. High or moderate certainty evidence suggested that resistance exercise with or without nutrition and the combination of resistance exercise with aerobic and balance training were the most effective interventions for improving quality of life compared to usual care (standardized mean difference from 0.68 to 1.11). Moderate certainty evidence showed that resistance and balance exercise plus nutrition (mean difference [MD]: 4.19 kg) was the most effective for improving handgrip strength (minimally important difference [MID]: 5 kg). Resistance and balance exercise with or without nutrition (MD: 0.16 m/s, moderate) were the most effective for improving physical function measured by usual gait speed (MID: 0.1 m/s). Moderate certainty evidence showed that resistance and balance exercise (MD: 1.85 s) was intermediately effective for improving physical function measured by timed up and go test (MID: 2.1 s). High certainty evidence showed that resistance and aerobic, or resistance and balance, or resistance and aerobic exercise plus nutrition (MD from 1.72 to 2.28 s) were intermediately effective for improving physical function measured by the five-repetition chair stand test (MID: 2.3 s).
CONCLUSIONS
In older adults with sarcopenia, high or moderate certainty evidence showed that resistance exercise with or without nutrition and the combination of resistance exercise with aerobic and balance training were the most effective interventions for improving quality of life. Adding nutritional interventions to exercise had a larger effect on handgrip strength than exercise alone while showing a similar effect on other physical function measures.
Topics: Female; Humans; Aged; Network Meta-Analysis; Sarcopenia; Exercise; Exercise Therapy; Muscle Strength
PubMed: 37057640
DOI: 10.1002/jcsm.13225 -
Ageing Research Reviews Dec 2020Chronic inflammation has been associated with sarcopenia and its components skeletal muscle strength and muscle mass. The aim of this systematic review and meta-analysis... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Chronic inflammation has been associated with sarcopenia and its components skeletal muscle strength and muscle mass. The aim of this systematic review and meta-analysis was to determine the relationship between systemic inflammation, muscle strength and/or muscle mass in adults.
METHODS
An electronic search using keywords such as 'acute phase proteins, cytokines and sarcopenia, muscle mass, muscle strength' was conducted via Pubmed, Web of Science and Embase from inception until the 30th of June 2020. A meta-analysis using correlation data was performed to determine the overall relationship between inflammation and muscle strength and muscle mass in adults.
RESULTS
Overall, 168 articles; 149 cross-sectional articles (n = 76,899 participants, 47.0 % male) and 19 longitudinal articles (n = 12,295 participants, 31.9 % male) met inclusion criteria. Independent of disease state, higher levels of C reactive protein (CRP), Interleukin (IL)-6 and Tumor necrosis factor (TNF)α were associated with lower handgrip and knee extension strength (CRP; r = -0.10, p < 0.001, IL-6; r = -0.13, p < 0.001, TNFα; r = -0.08, p < 0.001 and CRP; r = -0.18, p < 0.001, IL-6; r = -0.11, p < 0.001, TNFα; r = -0.13, p < 0.001 respectively) and muscle mass (CRP; r = -0.12, p < 0.001, IL-6; r = -0.09, p < 0.001, TNFα; r = -0.15, p < 0.001). Furthermore, higher levels of systemic inflammatory markers appeared to be associated with lower muscle strength and muscle mass over time.
CONCLUSION
Higher levels of circulating inflammatory markers are significantly associated with lower skeletal muscle strength and muscle mass.
Topics: Biomarkers; Cross-Sectional Studies; Female; Hand Strength; Humans; Inflammation; Male; Muscle Strength; Muscle, Skeletal; Sarcopenia
PubMed: 32992047
DOI: 10.1016/j.arr.2020.101185 -
Journal of Sports Sciences Jun 2017The purpose of this paper was to systematically review the current literature and elucidate the effects of total weekly resistance training (RT) volume on changes in... (Meta-Analysis)
Meta-Analysis Review
The purpose of this paper was to systematically review the current literature and elucidate the effects of total weekly resistance training (RT) volume on changes in measures of muscle mass via meta-regression. The final analysis comprised 34 treatment groups from 15 studies. Outcomes for weekly sets as a continuous variable showed a significant effect of volume on changes in muscle size (P = 0.002). Each additional set was associated with an increase in effect size (ES) of 0.023 corresponding to an increase in the percentage gain by 0.37%. Outcomes for weekly sets categorised as lower or higher within each study showed a significant effect of volume on changes in muscle size (P = 0.03); the ES difference between higher and lower volumes was 0.241, which equated to a percentage gain difference of 3.9%. Outcomes for weekly sets as a three-level categorical variable (<5, 5-9 and 10+ per muscle) showed a trend for an effect of weekly sets (P = 0.074). The findings indicate a graded dose-response relationship whereby increases in RT volume produce greater gains in muscle hypertrophy.
Topics: Humans; Muscle Strength; Muscle, Skeletal; Resistance Training; Time Factors
PubMed: 27433992
DOI: 10.1080/02640414.2016.1210197 -
International Journal of Environmental... Mar 2023Strength training in prepubertal children is one of the topics that has aroused the most interest and controversy among training professionals in recent years.... (Review)
Review
Strength training in prepubertal children is one of the topics that has aroused the most interest and controversy among training professionals in recent years. Therefore, the aim of the present study was to analyze the available scientific evidence on the influence of strength training variables on morphological and/or neuromuscular adaptations in healthy prepubertal populations with no previous experience in this type of training according to the descriptive sample characteristics. According to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis, 22 studies were selected after a systematic search and selection process using four electronic databases: Google Scholar, PubMed, Scopus, and SPORT Discus. Furthermore, the internal validity of the studies included was assessed using the modified PEDro scale. The sample consisted of 604 prepubertal children (age, 10.02 ± 0.75 years), of whom 473 were boys and 131 were girls, with 104 strength training programs recorded. Strength training resulted in a significant increase in jumping ( = 29) and sprinting ( = 13) abilities. Moreover, muscle strength was increased in 100% of the cases. Morphologically, strength training resulted in a decrease in body fat percentage ( = 19) and an increase in lean body mass ( = 17). With regard to gender, increases in general sport skills and basic physical abilities were significant in males but not in females. Thus, the results are more heterogeneous in girls due to the small number of studies carried out. Therefore, this research provides practical applications for coaches to design and implement more effective training programs to maximize adaptations, enhance physical performance, and reduce injury risk.
Topics: Male; Female; Humans; Child; Resistance Training; Muscle Strength; Sports; Adaptation, Physiological; Acclimatization
PubMed: 36981742
DOI: 10.3390/ijerph20064833 -
Journal of Science and Medicine in Sport Sep 2018Inadequate sleep (e.g., an insufficient duration of sleep per night) can reduce physical performance and has been linked to adverse metabolic health outcomes. Resistance... (Review)
Review
OBJECTIVES
Inadequate sleep (e.g., an insufficient duration of sleep per night) can reduce physical performance and has been linked to adverse metabolic health outcomes. Resistance exercise is an effective means to maintain and improve physical capacity and metabolic health, however, the outcomes for populations who may perform resistance exercise during periods of inadequate sleep are unknown. The primary aim of this systematic review was to evaluate the effect of sleep deprivation (i.e. no sleep) and sleep restriction (i.e. a reduced sleep duration) on resistance exercise performance. A secondary aim was to explore the effects on hormonal indicators or markers of muscle protein metabolism.
METHODS
A systematic search of five electronic databases was conducted with terms related to three combined concepts: inadequate sleep; resistance exercise; performance and physiological outcomes. Study quality and biases were assessed using the Effective Public Health Practice Project quality assessment tool.
RESULTS
Seventeen studies met the inclusion criteria and were rated as 'moderate' or 'weak' for global quality. Sleep deprivation had little effect on muscle strength during resistance exercise. In contrast, consecutive nights of sleep restriction could reduce the force output of multi-joint, but not single-joint movements. Results were conflicting regarding hormonal responses to resistance training.
CONCLUSION
Inadequate sleep impairs maximal muscle strength in compound movements when performed without specific interventions designed to increase motivation. Strategies to assist groups facing inadequate sleep to effectively perform resistance training may include supplementing their motivation by training in groups or ingesting caffeine; or training prior to prolonged periods of wakefulness.
Topics: Humans; Muscle Strength; Muscle, Skeletal; Resistance Training; Sleep; Sleep Deprivation
PubMed: 29422383
DOI: 10.1016/j.jsams.2018.01.012 -
BMC Geriatrics Nov 2021Health-promoting interventions are important for preventing frailty and sarcopenia in older adults. However, there is limited evidence that nutritional interventions... (Meta-Analysis)
Meta-Analysis
Does the combination of resistance training and a nutritional intervention have a synergic effect on muscle mass, strength, and physical function in older adults? A systematic review and meta-analysis.
BACKGROUND
Health-promoting interventions are important for preventing frailty and sarcopenia in older adults. However, there is limited evidence that nutritional interventions yield additional effects when combined with resistance training. This systematic review and meta-analysis aimed to compare the effectiveness of nutritional interventions with resistance training and that of resistance training alone.
METHODS
Randomized controlled trials published in peer-reviewed journals prior to July 2020 were retrieved from databases and other sources. The articles were screened according to the inclusion and exclusion criteria. The methodological quality of the included studies was assessed using Cochrane's risk of bias tool 2. A meta-analysis was performed using the RevMan 5.4 program and STATA 16 program.
RESULTS
A total of 22 studies were included in the meta-analysis. The results of the meta-analysis showed no significant differences between groups in muscle mass, muscle strength, or physical functional performance. In the subgroup analysis regarding the types of nutritional interventions, creatine showed significant effects on lean body mass (n = 4, MD 2.61, 95% CI 0.51 to 4.72). Regarding the other subgroup analyses, there were no significant differences in appendicular skeletal muscle mass (p = .43), hand grip strength (p = .73), knee extension strength (p = .09), chair stand test results (p = .31), or timed up-and-go test results (p = .31). In the meta-regression, moderators such as the mean age of subjects and duration of interventions were not associated with outcome variables.
CONCLUSIONS
This meta-analysis showed that nutritional interventions with resistance training have no additional effect on body composition, muscle strength, or physical function. Only creatine showed synergistic effects with resistance training on muscle mass.
TRIAL REGISTRATION
CRD42021224843 .
Topics: Aged; Hand Strength; Humans; Muscle Strength; Muscle, Skeletal; Muscles; Resistance Training; Sarcopenia
PubMed: 34772342
DOI: 10.1186/s12877-021-02491-5 -
PloS One 2021Rheumatoid arthritis(RA) and osteoarthritis(OA) patients showed systemic manifestations that may lead to a reduction in muscle strength, muscle mass and, consequently,...
The effects of resistance training with blood flow restriction on muscle strength, muscle hypertrophy and functionality in patients with osteoarthritis and rheumatoid arthritis: A systematic review with meta-analysis.
INTRODUCTION
Rheumatoid arthritis(RA) and osteoarthritis(OA) patients showed systemic manifestations that may lead to a reduction in muscle strength, muscle mass and, consequently, to a reduction in functionality. On the other hand, moderate intensity resistance training(MIRT) and high intensity resistance training(HIRT) are able to improve muscle strength and muscle mass in RA and OA without affecting the disease course. However, due to the articular manifestations caused by these diseases, these patients may present intolerance to MIRT or HIRT. Thus, the low intensity resistance training combined with blood flow restriction(LIRTBFR) may be a new training strategy for these populations.
OBJECTIVE
To perform a systematic review with meta-analysis to verify the effects of LIRTBFR on muscle strength, muscle mass and functionality in RA and OA patients.
MATERIALS AND METHODS
A systematic review with meta-analysis of randomized clinical trials(RCTs), published in English, between 1957-2021, was conducted using MEDLINE(PubMed), Embase and Cochrane Library. The methodological quality was assessed using Physiotherapy Evidence Database scale. The risk of bias was assessed using RoB2.0. Mean difference(MD) or standardized mean difference(SMD) and 95% confidence intervals(CI) were pooled using a random-effects model. A P<0.05 was considered statistically significant.
RESULTS
Five RCTs were included. We found no significant differences in the effects between LIRTBFR, MIRT and HIRT on muscle strength, which was assessed by tests of quadriceps strength(SMD = -0.01[-0.57, 0.54], P = 0.96; I² = 58%) and functionality measured by tests with patterns similar to walking(SMD = -0.04[-0.39, 0.31], P = 0.82; I² = 0%). Compared to HIRT, muscle mass gain after LIRTBFR was reported to be similar. When comparing LIRTBFR with low intensity resistance training without blood flow restriction(LIRT), the effect LIRTBFR was reported to be higher on muscle strength, which was evaluated by the knee extension test.
CONCLUSION
LIRTBFR appears to be a promising strategy for gains in muscle strength, muscle mass and functionality in a predominant sample of RA and OA women.
Topics: Arthritis, Rheumatoid; Blood Flow Restriction Therapy; Hemodynamics; Humans; Hypertrophy; Muscle Strength; Resistance Training
PubMed: 34758045
DOI: 10.1371/journal.pone.0259574 -
Sports Medicine (Auckland, N.Z.) Aug 2022Older adults experience considerable muscle and bone loss that are closely interconnected. The efficacy of progressive resistance training programs to concurrently... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Older adults experience considerable muscle and bone loss that are closely interconnected. The efficacy of progressive resistance training programs to concurrently reverse/slow the age-related decline in muscle strength and bone mineral density (BMD) in older adults remains unclear.
OBJECTIVES
We aimed to quantify concomitant changes in lower-body muscle strength and BMD in older adults following a progressive resistance training program and to determine how these changes are influenced by mode (resistance only vs. combined resistance and weight-bearing exercises), frequency, volume, load, and program length.
METHODS
MEDLINE/PubMed and Embase databases were searched for articles published in English before 1 June, 2021. Randomized controlled trials reporting changes in leg press or knee extension one repetition maximum and femur/hip or lumbar spine BMD following progressive resistance training in men and/or women ≥ 65 years of age were included. A random-effects meta-analysis and meta-regression determined the effects of resistance training and the individual training characteristics on the percent change (∆%) in muscle strength (standardized mean difference) and BMD (mean difference). The quality of the evidence was assessed using the Cochrane risk-of-bias tool (version 2.0) and Grading of Recommendation, Assessment, Development, and Evaluation (GRADE) criteria.
RESULTS
Seven hundred and eighty studies were identified and 14 were included. Progressive resistance training increased muscle strength (∆ standardized mean difference = 1.1%; 95% confidence interval 0.73, 1.47; p ≤ 0.001) and femur/hip BMD (∆ mean difference = 2.77%; 95% confidence interval 0.44, 5.10; p = 0.02), but not BMD of the lumbar spine (∆ mean difference = 1.60%; 95% confidence interval - 1.44, 4.63; p = 0.30). The certainty for improvement was greater for muscle strength compared with BMD, evidenced by less heterogeneity (I = 78.1% vs 98.6%) and a higher overall quality of evidence. No training characteristic significantly affected both outcomes (p > 0.05), although concomitant increases in strength and BMD were favored by higher training frequencies, increases in strength were favored by resistance only and higher volumes, and increases in BMD were favored by combined resistance plus weight-bearing exercises, lower volumes, and higher loads.
CONCLUSIONS
Progressive resistance training programs concomitantly increase lower-limb muscle strength and femur/hip bone mineral density in older adults, with greater certainty for strength improvement. Thus, to maximize the efficacy of progressive resistance training programs to concurrently prevent muscle and bone loss in older adults, it is recommended to incorporate training characteristics more likely to improve BMD.
Topics: Aged; Bone Density; Exercise; Female; Humans; Male; Muscle Strength; Resistance Training; Weight Lifting
PubMed: 35608815
DOI: 10.1007/s40279-022-01675-2 -
Journal of Sport Rehabilitation Jul 2022Unilateral training of the uninjured limb could be a useful therapeutic tool to induce cross-education in periods of immobilization, however, the effectiveness of this... (Meta-Analysis)
Meta-Analysis
Effectiveness of Unilateral Training of the Uninjured Limb on Muscle Strength and Knee Function of Patients With Anterior Cruciate Ligament Reconstruction: A Systematic Review and Meta-Analysis of Cross-Education.
CONTEXT
Unilateral training of the uninjured limb could be a useful therapeutic tool to induce cross-education in periods of immobilization, however, the effectiveness of this training in patients with anterior cruciate ligament (ACL) reconstruction is unknown.
OBJECTIVE
To determine the effectiveness of unilateral training of the uninjured limb on muscle strength and knee function in patients with ACL reconstruction.
DESIGN
Systematic review and meta-analysis.
EVIDENCE ACQUISITION
An electronic search was performed in the MEDLINE, LILACS, CENTRAL, Embase, Scopus, Web of Science, CINAHL, SPORTDiscus, and PEDro databases from inception until March 2021. The authors included randomized clinical trials that evaluated the effectiveness of unilateral training of the uninjured limb on muscle strength and knee function in patients after ACL reconstruction.
EVIDENCE SYNTHESIS
Seven clinical trials met the eligibility criteria, and for the quantitative synthesis, 5 studies were included. The standardized mean difference for isometric quadriceps strength was 0.60 at 8 to 12 weeks (95% confidence interval, 0.29 to 0.92; P = .01; I2 = 6%). There was a high quality of evidence according to the Grading of Recommendation, Assessment, Development and Evaluation rating. Four studies assessed knee function through different self-administered questionnaires at 8, 24, and 26 weeks. Only one study reported significant differences in knee function at 8 weeks, favoring the unilateral training group.
CONCLUSIONS
There was a moderate to high quality of evidence, with statistical significance that the addition of unilateral training to standard rehabilitation improved the cross-education of quadriceps strength after ACL reconstruction. More research is needed to assess the consistency of these results. International Prospective Register of Systematic Reviews registration number: CRD42020199950.
Topics: Anterior Cruciate Ligament Injuries; Anterior Cruciate Ligament Reconstruction; Humans; Knee; Lower Extremity; Muscle Strength; Quadriceps Muscle
PubMed: 35279020
DOI: 10.1123/jsr.2021-0204