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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 -
Journal of the International Society of... 2016Consumption of pre-workout dietary supplements by both recreational and competitive athletes has increased dramatically in recent years. The purpose of this study was to... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
Consumption of pre-workout dietary supplements by both recreational and competitive athletes has increased dramatically in recent years. The purpose of this study was to determine the acute effects of a caffeine-containing pre-workout dietary supplement on various measures of performance including anaerobic power, upper and lower body power, and upper body strength in recreationally trained males.
METHODS
Thirteen males (mean ± SD age = 24 ± 6 yrs; height = 180.3 ± 5 cm; body mass = 83.4 ± 9 kg) participated in this investigation in which they reported to the laboratory on four separate occasions, each separated by one week. Each subject underwent an initial familiarization session on week one followed by baseline (BA) performance testing on week two. Performance testing included a medicine ball put (MBP) to determine upper body explosive power, vertical jump test (VJ) to determine lower body explosive power, one-rep maximum bench press (1-RM) for determining upper body strength, and a Wingate Anaerobic Power Test (WAnT) to determine measures of anaerobic power. On week three, subjects were randomly assigned to ingest either a pre-workout supplement (SUP) or a placebo (PL) and again complete the performance testing protocol. Subjects were provided with the crossover treatment on the fourth and final week. Performance testing commenced 20-minute following ingestion of both treatments, which was similar to previous investigations.
RESULTS
Significant differences in anaerobic peak power relative to the WAnT were observed following ingestion of the SUP (782 ± 191 W) in comparison to the PL (722 ± 208 W; p = 0.003; effect size = 0.30) and BA (723 ± 205 W; p = 0.011; effect size = 0.28). Significant differences were also observed for anaerobic mean power following ingestion of the SUP (569 ± 133 W) in comparison to the PL (535 ± 149 W; p = 0.006; effect size = 0.24) and BA (538 ± 148 W; p = 0.020; effect size = 0.22). No significant differences between trials were observed for upper body power, lower body power, or upper body strength.
CONCLUSIONS
Ingestion of the pre-workout dietary supplement led to significant improvements in anaerobic peak and mean power values in comparison to the placebo and baseline treatments. No improvements were observed in upper and lower body power or upper body strength. Taken prior to exercise, a caffeine-containing pre-workout dietary supplement may improve anaerobic power performance.
Topics: Anaerobic Threshold; Cross-Over Studies; Dietary Supplements; Double-Blind Method; Exercise; Food, Formulated; Humans; Male; Muscle Strength; Muscle, Skeletal; Physical Endurance; Resistance Training; Sports Nutritional Physiological Phenomena; Young Adult
PubMed: 27429596
DOI: 10.1186/s12970-016-0138-7 -
International Journal of Environmental... Jul 2022This study aimed to analyze the efficacy of exercise interventions on muscle strength, muscle mass, and physical performance in older adults with sarcopenia. Randomized... (Meta-Analysis)
Meta-Analysis Review
This study aimed to analyze the efficacy of exercise interventions on muscle strength, muscle mass, and physical performance in older adults with sarcopenia. Randomized controlled studies assessing exercise effects on sarcopenia were searched in Web of Science, PubMed, Cochrane Library, ProQuest, EBSCOhost, Scopus, EMBASE, and VIP and CNKI up to 31 March 2022. Data were expressed as weighted/standardized mean difference (MD/SMD) with 95% confidence intervals (CI). I index was employed for heterogeneity. The initial search identified 5379 studies, and 23 studies involving 1252 participants met the inclusion criteria for further analysis. Results revealed that exercise interventions can significantly improve grip strength (MD = 2.38, 95%CI = 1.33-3.43), knee extension strength (SMD = 0.50, 95%CI = 0.36-0.64), muscle mass of lower extremities (MD = 0.28, 95%CI = 0.01-0.56), walking speed (SMD = 0.88, 95%CI = 0.49-1.27), and functional mobility (MD = -1.77, 95%CI = -2.11--1.42) among older adults with sarcopenia. No significant exercise effects were found on fat-free muscle mass, appendicular muscle mass, skeletal muscle mass, and muscle mass of the upper extremities. The results of subgroup analysis indicated that both resistance training and multicomponent exercise could significantly increase the muscle strength, while aerobic exercise did not. The findings suggest that exercise intervention can effectively improve muscle function and physical performance in older adults with sarcopenia, but has limited effects on the muscle mass of the upper extremities. In addition, it is highly recommended to apply group-based and supervised resistance training and multicomponent exercise in the prevention and treatment of sarcopenia among the older population.
Topics: Aged; Exercise; Humans; Muscle Strength; Muscle, Skeletal; Physical Functional Performance; Sarcopenia
PubMed: 35805870
DOI: 10.3390/ijerph19138212 -
Journal of Cachexia, Sarcopenia and... Feb 2023Probiotics have shown potential to counteract sarcopenia, although the extent to which they can influence domains of sarcopenia such as muscle mass and strength in... (Meta-Analysis)
Meta-Analysis Review
Probiotics have shown potential to counteract sarcopenia, although the extent to which they can influence domains of sarcopenia such as muscle mass and strength in humans is unclear. The aim of this systematic review and meta-analysis was to explore the impact of probiotic supplementation on muscle mass, total lean mass and muscle strength in human adults. A literature search of randomized controlled trials (RCTs) was conducted through PubMed, Scopus, Web of Science and Cochrane Library from inception until June 2022. Eligible RCTs compared the effect of probiotic supplementation versus placebo on muscle and total lean mass and global muscle strength (composite score of all muscle strength outcomes) in adults (>18 years). To evaluate the differences between groups, a meta-analysis was conducted using the random effects inverse-variance model by utilizing standardized mean differences. Twenty-four studies were included in the systematic review and meta-analysis exploring the effects of probiotics on muscle mass, total lean mass and global muscle strength. Our main analysis (k = 10) revealed that muscle mass was improved following probiotics compared with placebo (SMD: 0.42, 95% CI: 0.10-0.74, I = 57%, P = 0.009), although no changes were revealed in relation to total lean mass (k = 12; SMD: -0.03, 95% CI: -0.19 - 0.13, I = 0%, P = 0.69). Interestingly, a significant increase in global muscle strength was also observed among six RCTs (SMD: 0.69, 95% CI: 0.33-1.06, I = 64%, P = 0.0002). Probiotic supplementation enhances both muscle mass and global muscle strength; however, no beneficial effects were observed in total lean mass. Investigating the physiological mechanisms underpinning different ageing groups and elucidating appropriate probiotic strains for optimal gains in muscle mass and strength are warranted.
Topics: Adult; Humans; Sarcopenia; Randomized Controlled Trials as Topic; Probiotics; Muscle Strength; Muscles
PubMed: 36414567
DOI: 10.1002/jcsm.13132 -
Brazilian Journal of Physical Therapy 2018Muscle strength is an important component of health.
BACKGROUND
Muscle strength is an important component of health.
OBJECTIVE
To describe and evaluate the studies which have established the reference values for muscle strength on healthy individuals and to synthesize these values with a descriptive meta-analysis approach.
METHODS
A systematic review was performed in MEDLINE, LILACS, and SciELO databases. Studies that investigated the reference values for muscle strength of two or more appendicular/axial muscle groups of health individuals were included. Methodological quality, including risk of bias was assessed by the QUADAS-2. Data extracted included: country of the study, sample size, population characteristics, equipment/method used, and muscle groups evaluated.
RESULTS
Of the 414 studies identified, 46 were included. Most of the studies had adequate methodological quality. Included studies evaluated: appendicular (80.4%) and axial (36.9%) muscles; adults (78.3%), elderly (58.7%), adolescents (43.5%), children (23.9%); isometric (91.3%) and isokinetic (17.4%) strength. Six studies (13%) with similar procedures were synthesized with meta-analysis. Generally, the coefficient of variation values that resulted from the meta-analysis ranged from 20.1% to 30% and were similar to those reported by the original studies. The meta-analysis synthesized the reference values of isometric strength of 14 muscle groups of the dominant/non-dominant sides of the upper/lower limbs of adults/elderly from developed countries, using dynamometers/myometer.
CONCLUSIONS
Most of the included studies had adequate methodological quality. The meta-analysis provided reference values for the isometric strength of 14 appendicular muscle groups of the dominant/non-dominant sides, measured with dynamometers/myometers, of men/women, of adults/elderly. These data may be used to interpret the results of the evaluations and establish appropriate treatment goals.
Topics: Humans; Muscle Strength; Reference Values
PubMed: 29764761
DOI: 10.1016/j.bjpt.2018.02.006 -
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 -
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 -
International Journal of Environmental... Nov 2022Resistance exercise effectively improves bone mineral density (BMD) and muscle quality (e.g., muscle mass and muscle strength). The present study aimed to examine the... (Randomized Controlled Trial)
Randomized Controlled Trial
Effects of Twenty-Four Weeks of Resistance Exercise Training on Body Composition, Bone Mineral Density, Functional Fitness and Isokinetic Muscle Strength in Obese Older Women: A Randomized Controlled Trial.
Resistance exercise effectively improves bone mineral density (BMD) and muscle quality (e.g., muscle mass and muscle strength). The present study aimed to examine the effect of a 24-week resistance exercise training (RT) program on body composition, BMD, functional fitness, and isokinetic muscle strength in obese older women. Forty obese older women were initially enrolled. Among them, 30 participants (age: 80.55 ± 4.94 years; body fat percentage: 36.25 ± 3.44%) completed the study. The participants were randomly assigned into two groups: the RT group (n = 15) and the control (CON) group (n = 15). The RT group participated in the exercise for 60 min per session and two sessions per week for 24 weeks. Pre-test and post-test body composition, BMD, functional fitness, and isokinetic muscle strength were evaluated. The RT group increased significantly in functional fitness (hand grip strength: 1.70 kg, < 0.01, and lower body strength: 3.87 n, < 0.001), and isokinetic muscle strength (non-dominant leg extensor peak torque %BW at 60°/s: 13.20%, < 0.05, dominant leg (DL) flexor peak torque at 60°/s: 3.87 Nm, < 0.05, and DL flexor peak torque %BW at 60°/s: 7.60%, < 0.05). However, the CON group showed negative changes in body composition (fat mass: 1.15 kg, < 0.001, body fat percentage: 1.59%, < 0.001, and fat-free mass: -0.58 kg, < 0.05), BMD (whole-body: -0.01 g/cm, < 0.001 and forearm: -0.01 g/cm, < 0.05), functional fitness (lower body flexibility: -3.23 cm, < 0.01, upper body strength: -2.06 n, < 0.01, and agility and dynamic balance: 0.54 s, < 0.01), and isokinetic muscle strength at 60°/s and 180°/s (all peak torque % body weight variables: -7.31--1.50, < 0.05). Our findings show that the CON group negatively affects body composition, BMD, functional fitness, and isokinetic muscle strength in obese older women for 24 weeks.
Topics: Humans; Female; Aged; Aged, 80 and over; Resistance Training; Bone Density; Hand Strength; Muscle, Skeletal; Muscle Strength; Body Composition; Obesity
PubMed: 36361434
DOI: 10.3390/ijerph192114554 -
Medicine Jun 2018Controversy exists regarding whether the kinesiology tape application direction affects muscle strength. (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
Controversy exists regarding whether the kinesiology tape application direction affects muscle strength.
METHODS
Eighteen healthy volunteers (12 men, 6 women) participated. Kinesiology tape was randomly applied to the quadriceps muscles either from origin to insertion or from insertion to origin. A Biodex isokinetic dynamometer was used to measure the peak torque of the quadriceps pre-and post-taping.
RESULTS
There was a significant difference in muscle strength after taping, regardless of the kinesiology tape application direction. There were no significant differences in the peak torque of the quadriceps between the 2 kinesiology tape application directions.
CONCLUSIONS
The application of kinesiology tape application to the rectus femoris, vastus medialis, and vastus lateralis of the quadriceps increased the muscle torque, regardless of the tape application direction. Therefore, to enhance quadriceps strength, we recommend the application of kinesiology tape to 3 of the muscles of the quadriceps (specifically, the rectus femoris, vastus medialis and vastus lateralis), irrespective of the tape application direction.
Topics: Adult; Athletic Tape; Cross-Over Studies; Female; Healthy Volunteers; Humans; Kinesiology, Applied; Male; Muscle Strength; Muscle Strength Dynamometer; Quadriceps Muscle; Torque
PubMed: 29901599
DOI: 10.1097/MD.0000000000011038 -
European Review For Medical and... Mar 2022The aim of the study was to investigate the effect of a 3-month, trampoline-based stretch-shortening cycle (SSC) exercises on muscle strength and postural control in... (Randomized Controlled Trial)
Randomized Controlled Trial
Distinct effects of trampoline-based stretch-shortening cycle exercises on muscle strength and postural control in children with Down syndrome: a randomized controlled study.
OBJECTIVE
The aim of the study was to investigate the effect of a 3-month, trampoline-based stretch-shortening cycle (SSC) exercises on muscle strength and postural control in children with Down's syndrome (DS).
PATIENTS AND METHODS
Thirty-two children with DS aged between 7-9 years were enrolled and randomly assigned into the control group (n = 16); received standard physical therapy (sPT) or SSC group (n = 16); received sPT in addition to a 15-minute, trampoline-based SSC training program twice per week for 12 successive weeks. Lower limb muscle strength and postural stability [anterior/posterior stability index (A/P-SI), medial/lateral stability index (M/L-SI)], and overall stability index (O-SI) were assessed pre- and post-treatment.
RESULTS
Strength of hip extensor (p=0.034) and adductor (p=0.015), knee extensor (p=0.028) and flexor (p=0.01), and ankle dorsi (p=0.033) and plantar flexor (p=0.007) muscles increased significantly in the SSC group when compared with the control group. Also, the A/P-SI (p=0.019), M/L-SI (p=0.002), and O-SI (p=0.021) decreased significantly in the SSC group when compared with the control group, suggesting better postural control.
CONCLUSIONS
Twelve weeks of trampoline-based SSC exercises are likely effective for enhancing muscle strength and postural control in children with DS and should consequently be included in the rehabilitation programs for these children.
Topics: Child; Down Syndrome; Exercise Therapy; Humans; Muscle Strength; Plyometric Exercise; Postural Balance
PubMed: 35363345
DOI: 10.26355/eurrev_202203_28343