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Sports Medicine (Auckland, N.Z.) Mar 2022Both athletes and recreational exercisers often perform relatively high volumes of aerobic and strength training simultaneously. However, the compatibility of these two... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Both athletes and recreational exercisers often perform relatively high volumes of aerobic and strength training simultaneously. However, the compatibility of these two distinct training modes remains unclear.
OBJECTIVE
This systematic review assessed the compatibility of concurrent aerobic and strength training compared with strength training alone, in terms of adaptations in muscle function (maximal and explosive strength) and muscle mass. Subgroup analyses were conducted to examine the influence of training modality, training type, exercise order, training frequency, age, and training status.
METHODS
A systematic literature search was conducted according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. PubMed/MEDLINE, ISI Web of Science, Embase, CINAHL, SPORTDiscus, and Scopus were systematically searched (12 August 2020, updated on 15 March 2021). Eligibility criteria were as follows.
POPULATION
healthy adults of any sex and age; Intervention: supervised concurrent aerobic and strength training for at least 4 weeks; Comparison: identical strength training prescription, with no aerobic training; Outcome: maximal strength, explosive strength, and muscle hypertrophy.
RESULTS
A total of 43 studies were included. The estimated standardised mean differences (SMD) based on the random-effects model were - 0.06 (95% confidence interval [CI] - 0.20 to 0.09; p = 0.446), - 0.28 (95% CI - 0.48 to - 0.08; p = 0.007), and - 0.01 (95% CI - 0.16 to 0.18; p = 0.919) for maximal strength, explosive strength, and muscle hypertrophy, respectively. Attenuation of explosive strength was more pronounced when concurrent training was performed within the same session (p = 0.043) than when sessions were separated by at least 3 h (p > 0.05). No significant effects were found for the other moderators, i.e. type of aerobic training (cycling vs. running), frequency of concurrent training (> 5 vs. < 5 weekly sessions), training status (untrained vs. active), and mean age (< 40 vs. > 40 years).
CONCLUSION
Concurrent aerobic and strength training does not compromise muscle hypertrophy and maximal strength development. However, explosive strength gains may be attenuated, especially when aerobic and strength training are performed in the same session. These results appeared to be independent of the type of aerobic training, frequency of concurrent training, training status, and age.
PROSPERO
CRD42020203777.
Topics: Adaptation, Physiological; Adult; Exercise; Humans; Infant; Infant, Newborn; Muscle Strength; Muscle, Skeletal; Resistance Training
PubMed: 34757594
DOI: 10.1007/s40279-021-01587-7 -
Ageing Research Reviews May 2021Engaging in physical activity (PA) and avoiding sedentary behavior (SB) are important for healthy ageing with benefits including the mitigation of disability and... (Meta-Analysis)
Meta-Analysis Review
The association of objectively measured physical activity and sedentary behavior with skeletal muscle strength and muscle power in older adults: A systematic review and meta-analysis.
BACKGROUND
Engaging in physical activity (PA) and avoiding sedentary behavior (SB) are important for healthy ageing with benefits including the mitigation of disability and mortality. Whether benefits extend to key determinants of disability and mortality, namely muscle strength and muscle power, is unclear.
AIMS
This systematic review aimed to describe the association of objective measures of PA and SB with measures of skeletal muscle strength and muscle power in community-dwelling older adults.
METHODS
Six databases were searched from their inception to June 21, 2020 for articles reporting associations between objectively measured PA and SB and upper body or lower body muscle strength or muscle power in community dwelling adults aged 60 years and older. An overview of associations was visualized by effect direction heat maps, standardized effect sizes were estimated with albatross plots and summarized in box plots. Articles reporting adjusted standardized regression coefficients (β) were included in meta-analyses.
RESULTS
A total of 112 articles were included representing 43,796 individuals (range: 21 to 3726 per article) with a mean or median age from 61.0 to 88.0 years (mean 56.4 % female). Higher PA measures and lower SB were associated with better upper body muscle strength (hand grip strength), upper body muscle power (arm curl), lower body muscle strength, and lower body muscle power (chair stand test). Median standardized effect sizes were consistently larger for measures of PA and SB with lower compared to upper body muscle strength and muscle power. The meta-analyses of adjusted β coefficients confirmed the associations between total PA (TPA), moderate-to-vigorous PA (MVPA) and light PA (LPA) with hand grip strength (β = 0.041, β = 0.057, and β = 0.070, respectively, all p ≤ 0.001), and TPA and MVPA with chair stand test (β = 0.199 and β = 0.211, respectively, all p ≤ 0.001).
CONCLUSIONS
Higher PA and lower SB are associated with greater skeletal muscle strength and muscle power, particularly with the chair stand test.
Topics: Aged; Aged, 80 and over; Exercise; Female; Hand Strength; Humans; Male; Middle Aged; Muscle Strength; Muscle, Skeletal; Sedentary Behavior
PubMed: 33607291
DOI: 10.1016/j.arr.2021.101266 -
Sports Medicine (Auckland, N.Z.) Jan 2015Protein supplements are frequently consumed by athletes and recreationally active adults to achieve greater gains in muscle mass and strength and improve physical... (Review)
Review
BACKGROUND
Protein supplements are frequently consumed by athletes and recreationally active adults to achieve greater gains in muscle mass and strength and improve physical performance.
OBJECTIVE
This review provides a systematic and comprehensive analysis of the literature that tested the hypothesis that protein supplements accelerate gains in muscle mass and strength resulting in improvements in aerobic and anaerobic power. Evidence statements were created based on an accepted strength of recommendation taxonomy.
DATA SOURCES
English language articles were searched through PubMed and Google Scholar using protein and supplements together with performance, exercise, strength, and muscle, alone or in combination as keywords. Additional articles were retrieved from reference lists found in these papers.
STUDY SELECTION
Studies recruiting healthy adults between 18 and 50 years of age that evaluated the effects of protein supplements alone or in combination with carbohydrate on a performance metric (e.g., one repetition maximum or isometric or isokinetic muscle strength), metrics of body composition, or measures of aerobic or anaerobic power were included in this review. The literature search identified 32 articles which incorporated test metrics that dealt exclusively with changes in muscle mass and strength, 5 articles that implemented combined resistance and aerobic training or followed participants during their normal sport training programs, and 1 article that evaluated changes in muscle oxidative enzymes and maximal aerobic power.
STUDY APPRAISAL AND SYNTHESIS METHODS
All papers were read in detail, and examined for experimental design confounders such as dietary monitoring, history of physical training (i.e., trained and untrained), and the number of participants studied. Studies were also evaluated based on the intensity, frequency, and duration of training, the type and timing of protein supplementation, and the sensitivity of the test metrics.
RESULTS
For untrained individuals, consuming supplemental protein likely has no impact on lean mass and muscle strength during the initial weeks of resistance training. However, as the duration, frequency, and volume of resistance training increase, protein supplementation may promote muscle hypertrophy and enhance gains in muscle strength in both untrained and trained individuals. Evidence also suggests that protein supplementation may accelerate gains in both aerobic and anaerobic power.
LIMITATIONS
To demonstrate measureable gains in strength and performance with exercise training and protein supplementation, many of the studies reviewed recruited untrained participants. Since skeletal muscle responses to exercise and protein supplementation differ between trained and untrained individuals, findings are not easily generalized for all consumers who may be considering the use of protein supplements.
CONCLUSIONS
This review suggests that protein supplementation may enhance muscle mass and performance when the training stimulus is adequate (e.g., frequency, volume, duration), and dietary intake is consistent with recommendations for physically active individuals.
Topics: Adult; Athletic Performance; Dietary Carbohydrates; Dietary Proteins; Dietary Supplements; Humans; Muscle Strength; Muscle, Skeletal; Physical Education and Training; Resistance Training
PubMed: 25169440
DOI: 10.1007/s40279-014-0242-2 -
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 -
Intensive Care Medicine Feb 2017Early active mobilisation and rehabilitation in the intensive care unit (ICU) is being used to prevent the long-term functional consequences of critical illness. This... (Meta-Analysis)
Meta-Analysis Review
PURPOSE
Early active mobilisation and rehabilitation in the intensive care unit (ICU) is being used to prevent the long-term functional consequences of critical illness. This review aimed to determine the effect of active mobilisation and rehabilitation in the ICU on mortality, function, mobility, muscle strength, quality of life, days alive and out of hospital to 180 days, ICU and hospital lengths of stay, duration of mechanical ventilation and discharge destination, linking outcomes with the World Health Organization International Classification of Function Framework.
METHODS
A PRISMA checklist-guided systematic review and meta-analysis of randomised and controlled clinical trials.
RESULTS
Fourteen studies of varying quality including a total of 1753 patients were reviewed. Active mobilisation and rehabilitation had no impact on short- or long-term mortality (p > 0.05). Meta-analysis showed that active mobilisation and rehabilitation led to greater muscle strength (body function) at ICU discharge as measured using the Medical Research Council Sum Score (mean difference 8.62 points, 95% confidence interval (CI) 1.39-15.86), greater probability of walking without assistance (activity limitation) at hospital discharge (odds ratio 2.13, 95% CI 1.19-3.83), and more days alive and out of hospital to day 180 (participation restriction) (mean difference 9.69, 95% CI 1.7-17.66). There were no consistent effects on function, quality of life, ICU or hospital length of stay, duration of mechanical ventilation or discharge destination.
CONCLUSION
Active mobilisation and rehabilitation in the ICU has no impact on short- and long-term mortality, but may improve mobility status, muscle strength and days alive and out of hospital to 180 days.
REGISTRATION OF PROTOCOL NUMBER
CRD42015029836.
Topics: Critical Illness; Early Ambulation; Hospital Mortality; Humans; Intensive Care Units; Length of Stay; Motor Activity; Muscle Strength; Patient Discharge; Physical Therapy Modalities; Respiration, Artificial
PubMed: 27864615
DOI: 10.1007/s00134-016-4612-0 -
Ageing Research Reviews Dec 2022The potential role of Tai Chi in improving sarcopenia and frailty has been shown in randomized controlled trials (RCTs). This systematic review and meta-analysis aimed... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
The potential role of Tai Chi in improving sarcopenia and frailty has been shown in randomized controlled trials (RCTs). This systematic review and meta-analysis aimed to examine the effect of Tai Chi on muscle mass, muscle strength, physical function, and other geriatric syndromes in elderly individuals with sarcopenia and frailty.
METHODS
Systematic searches of the PubMed, Cochrane Library, PEDro, EMBASE, Web of Science, CINAHL, and Medline databases for RCTs published between 1989 and 2022 were conducted; the database searchers were supplemented with manual reference searches. The inclusion criteria were as follows: (1) the study was designed as a RCT; (2) Tai Chi was one of the intervention arms; (3) the participants had a minimum age of ≥ 60 years and were diagnosed with frailty or sarcopenia, and the diagnostic guidelines or criteria were mentioned; (4) the number of participants in each arm was ≥ 10; and (5) the outcome reports included ≥ 1 item from the following primary or secondary outcomes. The exclusion criteria were as follows: (1) non-RCT studies; (2) nonhuman subjects; (3) participants aged < 60 years; (4) no description of the diagnostic guidelines or criteria for frailty or sarcopenia in the text; and (5) reported outcomes not among the following primary or secondary outcomes. The primary outcomes were muscle mass, grip strength and muscle performance (gait speed, 30-second chair stand test (30CST), sit-to-stand test (SST), Timed up and go test (TUGT), balance, and the Short Physical Performance Battery (SPPB)). The secondary outcomes included the number of falls and fear of falling (FOF), diastolic blood pressure (DBP), Mini-Mental State Examination (MMSE) score, and depression and quality of life (QOL) assessments.
RESULTS
Eleven RCTs were conducted from 1996 to 2022 in 5 countries that investigated 1676 sarcopenic or frail elderly individuals were included in the review. There were 804 participants in the Tai Chi exercise cohort and 872 participants in the control cohort (nonexercised (n = 5)/ exercise (n = 8)). The mean age of participants was 70-89.5 years and the numbers of participants from each arm in each study were 10-158. The majority of the participants practiced Yang-style Tai Chi (n = 9), and the numbers of movement ranged from 6 to 24. The prescriptions of training were 8-48 weeks, 2-7 sessions per weeks, and 30-90 min per session. Most studies used Tai Chi expert as instructor (n = 8). The lengths of follow-up period were 8-48 weeks. The results from our meta-analysis revealed significant improvements for Tai Chi compared to control group (nonexercise/ exercise) on measures of the 30CST (weighted mean difference (WMD): 2.36, 95% confidence interval (CI) 1.50-3.21, p < 0.00001, I = 87%), the TUGT (WMD: -0.72, 95% CI -1.10 to -0.34, p = 0.0002, I =0%), numbers of fall (WMD: -0.41, 95% CI -0.64 to -0.17, p = 0.0006, I =0%) and FOF (standardized MD (SMD): -0.50, 95% CI -0.79 to -0.22, p = 0.0006, I = 57%); and for Tai Chi compared to 'nonexercise' controls on measures of SST (WMD: -2.20, 95% CI -2.22 to -2.18, p < 0.00001), balance (SMD: 9.85, 95% CI 8.88-10.82, p < 0.00001), DBP (WMD: -7.00, 95% CI -7.35 to -6.65, p < 0.00001), MMSE (WMD: 1.91, 95% CI 1.73-2.09, p < 0.00001, I =0%), depression (SMD: -1.37, 95% CI -1.91 to -0.83, p < 0.00001) and QOL (SMD: 10.72, 95% CI 9.38-12.07, p < 0.00001). There were no significant differences between Tai Chi and control groups on any of the remaining 4 comparisons: body muscle mass (WMD: 0.53, 95% CI -0.18 to 1.24; P = 0.14; I =0%), grip strength (WMD: -0.06, 95% CI -1.98 to 1.86; P = 0.95; I =0%), gait speed (WMD: 0.05, 95% CI -0.11 to 0.20; P = 0.55; I =99%), and SPPB (WMD: 0.55, 95% CI -0.04 to 1.14; P = 0.07). The variables of bias summary, Tai Chi instructor, Tai Chi movements, and Tai Chi training duration without significant association with the 30CST or the TUGT through meta-regression analyses.
CONCLUSIONS
Our results demonstrated that patients with frailty or sarcopenia who practiced Tai Chi exhibited improved physical performance in the 30-second chair stand test, the Timed up and go test, number of falls and fear of falling. However, there was no difference in muscle mass, grip strength, gait speed, or Short Physical Performance Battery score between the Tai Chi and control groups. Improvements in the sit-to-stand test, balance, diastolic blood pressure, Mini-Mental State Examination score, and depression and quality of life assessments were found when comparing the Tai Chi cohort to the nonexercise control cohort rather than the exercise control cohort. To explore the effectiveness of Tai Chi in sarcopenic and frail elderly individuals more comprehensively, a standardized Tai Chi training prescription and a detailed description of the study design are suggested for future studies.
Topics: Aged; Humans; Aged, 80 and over; Tai Ji; Sarcopenia; Frailty; Randomized Controlled Trials as Topic; Muscle Strength
PubMed: 36223875
DOI: 10.1016/j.arr.2022.101747 -
PloS One 2020The main purpose of this review was to systematically analyze the literature concerning studies which have investigated muscle activation when performing the Deadlift...
The main purpose of this review was to systematically analyze the literature concerning studies which have investigated muscle activation when performing the Deadlift exercise and its variants. This study was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis Statement (PRISMA). Original studies from inception until March 2019 were sourced from four electronic databases including PubMed, OVID, Scopus and Web of Science. Inclusion criteria were as follows: (a) a cross-sectional or longitudinal study design; (b) evaluation of neuromuscular activation during Deadlift exercise or variants; (c) inclusion of healthy and trained participants, with no injury issues at least for six months before measurements; and (d) analyzed "sEMG amplitude", "muscle activation" or "muscular activity" with surface electromyography (sEMG) devices. Major findings indicate that the biceps femoris is the most studied muscle, followed by gluteus maximus, vastus lateralis and erector spinae. Erector spinae and quadriceps muscles reported greater activation than gluteus maximus and biceps femoris muscles during Deadlift exercise and its variants. However, the Romanian Deadlift is associated with lower activation for erector spinae than for biceps femoris and semitendinosus. Deadlift also showed greater activation of the quadriceps muscles than the gluteus maximus and hamstring muscles. In general, semitendinosus muscle activation predominates over that of biceps femoris within hamstring muscles complex. In conclusion 1) Biceps femoris is the most evaluated muscle, followed by gluteus maximus, vastus lateralis and erector spinae during Deadlift exercises; 2) Erector spinae and quadriceps muscles are more activated than gluteus maximus and biceps femoris muscles within Deadlift exercises; 3) Within the hamstring muscles complex, semitendinosus elicits slightly greater muscle activation than biceps femoris during Deadlift exercises; and 4) A unified criterion upon methodology is necessary in order to report reliable outcomes when using surface electromyography recordings.
Topics: Electromyography; Exercise; Female; Humans; Male; Muscle Contraction; Muscle Strength; Muscle, Skeletal; Resistance Training
PubMed: 32107499
DOI: 10.1371/journal.pone.0229507 -
Nutrients Jan 2023(1) Background: In this study, a meta-analysis was performed to investigate the effects of whey protein, leucine, and vitamin D in sarcopenia; (2) Methods: We searched... (Meta-Analysis)
Meta-Analysis Review
(1) Background: In this study, a meta-analysis was performed to investigate the effects of whey protein, leucine, and vitamin D in sarcopenia; (2) Methods: We searched PubMed, Cochrane Library, Embase, and Scopus databases and retrieved studies published until 5 December 2022. Randomized controlled trials were included to evaluate muscle mass, strength, and function, after using whey protein, leucine, and vitamin D supplementation in patients with sarcopenia; (3) Results: A total of three studies including 637 patients reported the effectiveness of using whey protein, leucine, and vitamin D supplementation in patients with sarcopenia. Without considering whether or not a physical exercise program was combined with nutritional supplementation, no significant differences in grip strength or short physical performance battery (SPPB) scores between the experimental and control groups were noted. However, appendicular muscle mass significantly improved in the experimental group compared to the control group. The results were analyzed according to the presence or absence of a concomitant physical exercise program. With the use of a concomitant physical exercise program, handgrip strength and SPPB scores in the experimental group significantly improved when compared to the control group. In contrast, when physical exercise was not combined, there was no significant improvement in the handgrip strength and SPPB scores of patients with sarcopenia. In addition, the appendicular muscle mass significantly increased regardless of the presence of a concomitant physical exercise program; (4) Conclusions: Whey protein, leucine, and vitamin D supplementation can increase appendicular muscle mass in patients with sarcopenia. In addition, combining a physical exercise program with whey protein, leucine, and vitamin D supplementation can improve muscle strength and function.
Topics: Humans; Sarcopenia; Leucine; Whey Proteins; Hand Strength; Muscle, Skeletal; Muscle Strength; Vitamin D; Dietary Supplements
PubMed: 36771225
DOI: 10.3390/nu15030521 -
Sports Medicine (Auckland, N.Z.) Oct 2022Whole muscle hypertrophy does not appear to be negatively affected by concurrent aerobic and strength training compared to strength training alone. However, there are... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Whole muscle hypertrophy does not appear to be negatively affected by concurrent aerobic and strength training compared to strength training alone. However, there are contradictions in the literature regarding the effects of concurrent training on hypertrophy at the myofiber level.
OBJECTIVE
The current study aimed to systematically examine the extent to which concurrent aerobic and strength training, compared with strength training alone, influences type I and type II muscle fiber size adaptations. We also conducted subgroup analyses to examine the effects of the type of aerobic training, training modality, exercise order, training frequency, age, and training status.
DESIGN
A systematic literature search was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) [PROSPERO: CRD42020203777]. The registered protocol was modified to include only muscle fiber hypertrophy as an outcome.
DATA SOURCES
PubMed/MEDLINE, ISI Web of Science, Embase, CINAHL, SPORTDiscus, and Scopus were systematically searched on 12 August, 2020, and updated on 15 March, 2021.
ELIGIBILITY CRITERIA
Population: healthy adults of any sex and age; intervention: supervised, concurrent aerobic and strength training of at least 4 weeks; comparison: identical strength training prescription, with no aerobic training; and outcome: muscle fiber hypertrophy.
RESULTS
A total of 15 studies were included. The estimated standardized mean difference based on the random-effects model was - 0.23 (95% confidence interval [CI] - 0.46 to - 0.00, p = 0.050) for overall muscle fiber hypertrophy. The standardized mean differences were - 0.34 (95% CI - 0.72 to 0.04, p = 0.078) and - 0.13 (95% CI - 0.39 to 0.12, p = 0.315) for type I and type II fiber hypertrophy, respectively. A negative effect of concurrent training was observed for type I fibers when aerobic training was performed by running but not cycling (standardized mean difference - 0.81, 95% CI - 1.26 to - 0.36). None of the other subgroup analyses (i.e., based on concurrent training frequency, training status, training modality, and training order of same-session training) revealed any differences between groups.
CONCLUSIONS
In contrast to previous findings on whole muscle hypertrophy, the present results suggest that concurrent aerobic and strength training may have a small negative effect on fiber hypertrophy compared with strength training alone. Preliminary evidence suggests that this interference effect may be more pronounced when aerobic training is performed by running compared with cycling, at least for type I fibers.
Topics: Adult; Humans; Hypertrophy; Infant; Infant, Newborn; Muscle Fibers, Skeletal; Muscle Strength; Muscle, Skeletal; Resistance Training
PubMed: 35476184
DOI: 10.1007/s40279-022-01688-x -
Creatine Supplementation and Lower Limb Strength Performance: A Systematic Review and Meta-Analyses.Sports Medicine (Auckland, N.Z.) Sep 2015Creatine is the most widely used supplementation to increase strength performance. However, the few meta-analyses are more than 10 years old and suffer from inclusion... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Creatine is the most widely used supplementation to increase strength performance. However, the few meta-analyses are more than 10 years old and suffer from inclusion bias such as the absence of randomization and placebo, the diversity of the inclusion criteria (aerobic/endurance, anaerobic/strength), no evaluation on specific muscles or group of muscles, and the considerable amount of conflicting results within the last decade.
OBJECTIVE
The objective of this systematic review was to evaluate meta-analyzed effects of creatine supplementation on lower 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 of the lower limbs measured in exercises lasting less than 3 min. The search strategy used the keywords "creatine supplementation" and "performance". Dependent variables were creatine loading, total dose, duration, the time-intervals between baseline (T0) and the end of the supplementation (T1), as well as any training during supplementation. Independent variables were age, sex, and level of physical activity at baseline. We conducted meta-analyses at T1, and on changes between T0 and T1. Each meta-analysis was stratified within lower limb muscle groups and exercise tests.
RESULTS
We included 60 studies (646 individuals in the creatine supplementation group and 651 controls). At T1, the effect size (ES) among stratification for squat and leg press were, respectively, 0.336 (95 % CI 0.047-0.625, p = 0.023) and 0.297 (95 % CI 0.098-0.496, p = 0.003). Overall quadriceps ES was 0.266 (95 % CI 0.150-0.381, p < 0.001). Global lower limb ES was 0.235 (95 % CI 0.125-0.346, p < 0.001). Meta-analysis on changes between T0 and T1 gave similar results. The meta-regression showed no links with characteristics of population or of supplementation, demonstrating the creatine efficacy effects, independent of all listed conditions.
CONCLUSION
Creatine supplementation is effective in lower limb strength performance for exercise with a duration of less than 3 min, independent of population characteristic, training protocols, and supplementary doses and duration.
Topics: Adolescent; Adult; Aged; Creatine; Dietary Supplements; Female; Humans; Leg; Male; Middle Aged; Muscle Strength; Young Adult
PubMed: 25946994
DOI: 10.1007/s40279-015-0337-4