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British Journal of Sports Medicine Sep 2023To determine how distinct combinations of resistance training prescription (RTx) variables (load, sets and frequency) affect muscle strength and hypertrophy. (Meta-Analysis)
Meta-Analysis
OBJECTIVE
To determine how distinct combinations of resistance training prescription (RTx) variables (load, sets and frequency) affect muscle strength and hypertrophy.
DATA SOURCES
MEDLINE, Embase, Emcare, SPORTDiscus, CINAHL, and Web of Science were searched until February 2022.
ELIGIBILITY CRITERIA
Randomised trials that included healthy adults, compared at least 2 predefined conditions (non-exercise control (CTRL) and 12 RTx, differentiated by load, sets and/or weekly frequency), and reported muscle strength and/or hypertrophy were included.
ANALYSES
Systematic review and Bayesian network meta-analysis methodology was used to compare RTxs and CTRL. Surface under the cumulative ranking curve values were used to rank conditions. Confidence was assessed with threshold analysis.
RESULTS
The strength network included 178 studies (n=5097; women=45%). The hypertrophy network included 119 studies (n=3364; women=47%). All RTxs were superior to CTRL for muscle strength and hypertrophy. Higher-load (>80% of single repetition maximum) prescriptions maximised strength gains, and all prescriptions comparably promoted muscle hypertrophy. While the calculated effects of many prescriptions were similar, higher-load, multiset, thrice-weekly training (standardised mean difference (95% credible interval); 1.60 (1.38 to 1.82) vs CTRL) was the highest-ranked RTx for strength, and higher-load, multiset, twice-weekly training (0.66 (0.47 to 0.85) vs CTRL) was the highest-ranked RTx for hypertrophy. Threshold analysis demonstrated these results were extremely robust.
CONCLUSION
All RTx promoted strength and hypertrophy compared with no exercise. The highest-ranked prescriptions for strength involved higher loads, whereas the highest-ranked prescriptions for hypertrophy included multiple sets.
PROSPERO REGISTRATION NUMBER
CRD42021259663 and CRD42021258902.
Topics: Humans; Adult; Female; Resistance Training; Bayes Theorem; Network Meta-Analysis; Muscle, Skeletal; Muscle Strength; Hypertrophy; Prescriptions
PubMed: 37414459
DOI: 10.1136/bjsports-2023-106807 -
Metabolism: Clinical and Experimental Sep 2023Sarcopenia is a geriatric condition characterized by a progressive loss of skeletal muscle mass and strength, with an increased risk of adverse health outcomes (e.g.,... (Review)
Review
Sarcopenia is a geriatric condition characterized by a progressive loss of skeletal muscle mass and strength, with an increased risk of adverse health outcomes (e.g., falls, disability, institutionalization, reduced quality of life, mortality). Pharmacological remedies are currently unavailable for preventing the development of sarcopenia, halting its progression, or impeding its negative health outcomes. The most effective strategies to contrast sarcopenia rely on the adoption of healthier lifestyle behaviors, including adherence to high-quality diets and regular physical activity. In this review, the role of nutrition in the prevention and management of sarcopenia is summarized. Special attention is given to current "blockbuster" dietary regimes and agents used to counteract age-related muscle wasting, together with their putative mechanisms of action. Issues related to the design and implementation of effective nutritional strategies are discussed, with a focus on unanswered questions on the most appropriate timing of nutritional interventions to preserve muscle health and function into old age. A brief description is also provided on new technologies that can facilitate the development and implementation of personalized nutrition plans to contrast sarcopenia.
Topics: Humans; Aged; Sarcopenia; Muscle Strength; Quality of Life; Muscle, Skeletal; Diet
PubMed: 37352971
DOI: 10.1016/j.metabol.2023.155637 -
The American Journal of Clinical... Nov 2023Sarcopenia is a common skeletal muscle disorder characterized by a loss of muscle mass and impaired muscle function that is associated with poor health outcomes.... (Review)
Review
Sarcopenia is a common skeletal muscle disorder characterized by a loss of muscle mass and impaired muscle function that is associated with poor health outcomes. Although nutrition is considered an important factor in the etiology of sarcopenia, the preventive potential of diet, specifically the extent to which differences in habitual patterns of diet and/or nutrient intakes impact risk of its development, is poorly understood. This narrative review considered research evidence on dietary patterns and nutrient intakes in mid- (<60 y) and young-older (60-70 y) adulthood to evaluate how they relate to age-related changes in muscle mass and function. A key finding was that current evidence on adult diet and sarcopenia risk in older age is limited and fragmented, with different outcomes reported across studies (for example, lean mass, strength) and few reporting links to incident diagnosed sarcopenia. As these outcomes are not interchangeable, it challenges collation of the evidence, leaving many gaps in understanding. There is also limited information about adult (<70 y) diet and few longitudinal studies with repeated dietary assessments to enable definition of cumulative exposures across adulthood. However, despite these limitations, findings from studies of dietary patterns already provide reasonably consistent messages about the benefits of diets of higher quality in earlier adulthood for later physical performance, although whole-diet intervention trials are urgently needed to understand their potential. In comparison, there is little evidence of benefits of higher intakes of individual nutrients in earlier adulthood for later muscle mass and function. Although these gaps need to be addressed in future research, there may already be sufficient data to promote messages about diet quality more widely - that healthier diets of higher quality across adulthood, with known benefits for a range of health outcomes, are also linked to the effective preservation of muscle mass and function.
Topics: Adult; Humans; Sarcopenia; Muscle Strength; Muscle, Skeletal; Nutritional Status; Diet
PubMed: 37657521
DOI: 10.1016/j.ajcnut.2023.08.015 -
Nutrients Aug 2023To determine the effectiveness of whey protein (WP) supplementation during resistance exercise training (RET) vs. RET with or without placebo supplementation on skeletal... (Meta-Analysis)
Meta-Analysis Review
Effectiveness of Whey Protein Supplementation during Resistance Exercise Training on Skeletal Muscle Mass and Strength in Older People with Sarcopenia: A Systematic Review and Meta-Analysis.
OBJECTIVE
To determine the effectiveness of whey protein (WP) supplementation during resistance exercise training (RET) vs. RET with or without placebo supplementation on skeletal muscle mass, strength, and physical performance in older people with Sarcopenia.
METHODS
Electronic searches in the PubMed, Embase, Scopus, Web of Science, LILACS, SPORTDiscus, Epistemonikos, and CINAHL databases were performed until 20 January 2023. Randomized clinical trials conducted on sarcopenic adults aged 60 or older were included. The studies had to compare the effectiveness of the addition of supplements based on concentrated, isolated, or hydrolyzed whey protein during RET and compare it with RET with or without placebo supplementation on skeletal muscle mass and strength changes. The study selection process, data extraction, and risk of bias assessment were carried out by two independent reviewers.
RESULTS
Seven randomized clinical trials (591 participants) were included, and five of them provided data for quantitative synthesis. The overall pooled standardized mean difference (SMD) estimate showed a small effect size in favor of RET plus WP for skeletal muscle mass according to appendicular muscle index, with statistically significant differences compared with RET with or without the placebo group (SMD = 0.24; 95% CI, 0.05 to 0.42; = 0.01; = 0%, = 0.42). The overall pooled mean difference (MD) estimate showed a significant difference of +2.31 kg (MD = 2.31 kg; 95% CI, 0.01 to 4.6; = 0.05; = 81%, < 0.001) in handgrip strength in the RET plus WP group compared with the RET group with or without placebo. The narrative synthesis revealed discordance between the results of the studies on physical performance.
CONCLUSIONS
WP supplementation during RET is more effective in increasing handgrip strength and skeletal muscle mass in older people with Sarcopenia compared with RET with or without placebo supplementation. However, the effect sizes were small, and the MD did not exceed the minimally important clinical difference. The quality of the evidence was low to very low according, to the GRADE approach. Further research is needed in this field.
Topics: Adult; Humans; Aged; Sarcopenia; Whey Proteins; Muscle Strength; Muscle, Skeletal; Hand Strength; Resistance Training; Dietary Supplements
PubMed: 37571361
DOI: 10.3390/nu15153424 -
Nutrition Journal Jul 2023Resistance training adaptively increases muscle strength and mass, contributing to athletic performance and health promotion. Dietary intervention with natural foods... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
Resistance training adaptively increases muscle strength and mass, contributing to athletic performance and health promotion. Dietary intervention with natural foods provides nutrients that help accelerate muscle adaptation to training. Matcha green tea contains several bioactive factors such as antioxidants, amino acids, and dietary fibers; however, its effect on muscle adaptation is unclear. In this study, we aimed to investigate the effects of matcha beverage intake on muscle adaptation to resistance training.
METHODS
Healthy, untrained men were randomized into placebo and matcha groups. Participants consumed either a matcha beverage containing 1.5 g of matcha green tea powder or a placebo beverage twice a day and engaged in resistance training programs for 8 (trial 1) or 12 weeks (trial 2).
RESULTS
In trial 1, maximum leg strength after training tended to increase more in the matcha group than that in the placebo group. In the matcha group, subjective fatigue after exercise at 1 week of training was lower than that in the placebo group. Gut microbe analysis showed that the abundance of five genera changed after matcha intake. The change in Ruminococcus, Butyricimonas, and Oscillospira compositions positively correlated with the change in maximum strength. In trial 2, the change in skeletal muscle mass in response to training was larger in the matcha group. In addition, the salivary cortisol level was lower in the matcha group than that in the placebo group.
CONCLUSION
Daily intake of matcha green tea beverages may help in muscle adaptation to training, with modulations in stress and fatigue responses and microbiota composition.
Topics: Male; Humans; Antioxidants; Resistance Training; Tea; Muscle Strength; Exercise; Muscle, Skeletal
PubMed: 37403052
DOI: 10.1186/s12937-023-00859-4 -
Aging Cell Dec 2023The lifespan extension induced by 40% caloric restriction (CR) in rodents is accompanied by postponement of disease, preservation of function, and increased stress... (Randomized Controlled Trial)
Randomized Controlled Trial
The lifespan extension induced by 40% caloric restriction (CR) in rodents is accompanied by postponement of disease, preservation of function, and increased stress resistance. Whether CR elicits the same physiological and molecular responses in humans remains mostly unexplored. In the CALERIE study, 12% CR for 2 years in healthy humans induced minor losses of muscle mass (leg lean mass) without changes of muscle strength, but mechanisms for muscle quality preservation remained unclear. We performed high-depth RNA-Seq (387-618 million paired reads) on human vastus lateralis muscle biopsies collected from the CALERIE participants at baseline, 12- and 24-month follow-up from the 90 CALERIE participants randomized to CR and "ad libitum" control. Using linear mixed effect model, we identified protein-coding genes and splicing variants whose expression was significantly changed in the CR group compared to controls, including genes related to proteostasis, circadian rhythm regulation, DNA repair, mitochondrial biogenesis, mRNA processing/splicing, FOXO3 metabolism, apoptosis, and inflammation. Changes in some of these biological pathways mediated part of the positive effect of CR on muscle quality. Differentially expressed splicing variants were associated with change in pathways shown to be affected by CR in model organisms. Two years of sustained CR in humans positively affected skeletal muscle quality, and impacted gene expression and splicing profiles of biological pathways affected by CR in model organisms, suggesting that attainable levels of CR in a lifestyle intervention can benefit muscle health in humans.
Topics: Humans; Caloric Restriction; Longevity; Muscle, Skeletal; Muscle Strength
PubMed: 37823711
DOI: 10.1111/acel.13963 -
JAMA Network Open Mar 2024Sarcopenia and obesity are 2 global concerns associated with adverse health outcomes in older people. Evidence on the population-based prevalence of the combination of...
IMPORTANCE
Sarcopenia and obesity are 2 global concerns associated with adverse health outcomes in older people. Evidence on the population-based prevalence of the combination of sarcopenia with obesity (sarcopenic obesity [SO]) and its association with mortality are still limited.
OBJECTIVE
To investigate the prevalence of sarcopenia and SO and their association with all-cause mortality.
DESIGN, SETTING, AND PARTICIPANTS
This large-scale, population-based cohort study assessed participants from the Rotterdam Study from March 1, 2009, to June 1, 2014. Associations of sarcopenia and SO with all-cause mortality were studied using Kaplan-Meier curves, Cox proportional hazards regression, and accelerated failure time models fitted for sex, age, and body mass index (BMI). Data analysis was performed from January 1 to April 1, 2023.
EXPOSURES
The prevalence of sarcopenia and SO, measured based on handgrip strength and body composition (BC) (dual-energy x-ray absorptiometry) as recommended by current consensus criteria, with probable sarcopenia defined as having low handgrip strength and confirmed sarcopenia and SO defined as altered BC (high fat percentage and/or low appendicular skeletal muscle index) in addition to low handgrip strength.
MAIN OUTCOME AND MEASURE
The primary outcome was all-cause mortality, collected using linked mortality data from general practitioners and the central municipal records, until October 2022.
RESULTS
In the total population of 5888 participants (mean [SD] age, 69.5 [9.1] years; mean [SD] BMI, 27.5 [4.3]; 3343 [56.8%] female), 653 (11.1%; 95% CI, 10.3%-11.9%) had probable sarcopenia and 127 (2.2%; 95% CI, 1.8%-2.6%) had confirmed sarcopenia. Sarcopenic obesity with 1 altered component of BC was present in 295 participants (5.0%; 95% CI, 4.4%-5.6%) and with 2 altered components in 44 participants (0.8%; 95% CI, 0.6%-1.0%). An increased risk of all-cause mortality was observed in participants with probable sarcopenia (hazard ratio [HR], 1.29; 95% CI, 1.14-1.47) and confirmed sarcopenia (HR, 1.93; 95% CI, 1.53-2.43). Participants with SO plus 1 altered component of BC (HR, 1.94; 95% CI, 1.60-2.33]) or 2 altered components of BC (HR, 2.84; 95% CI, 1.97-4.11) had a higher risk of mortality than those without SO. Similar results for SO were obtained for participants with a BMI of 27 or greater.
CONCLUSIONS AND RELEVANCE
In this study, sarcopenia and SO were found to be prevalent phenotypes in older people and were associated with all-cause mortality. Additional alterations of BC amplified this risk independently of age, sex, and BMI. The use of low muscle strength as a first step of both diagnoses may allow for early identification of individuals at risk for premature mortality.
Topics: Humans; Female; Aged; Male; Sarcopenia; Cohort Studies; Hand Strength; Muscle Strength; Obesity
PubMed: 38526491
DOI: 10.1001/jamanetworkopen.2024.3604 -
Journal of Applied Physiology... Dec 2023Aging is typically associated with decreased muscle strength and rate of force development (RFD), partly explained by motor unit remodeling due to denervation, and...
Aging is typically associated with decreased muscle strength and rate of force development (RFD), partly explained by motor unit remodeling due to denervation, and subsequent loss of fast-twitch type II myofibers. Exercise is commonly advocated to counteract this detrimental loss. However, it is unclear how life-long strength versus endurance training may differentially affect markers of denervation and reinnervation of skeletal myofibers and, in turn, affect the proportion and morphology of fast-twitch type II musculature. Thus, we compared fiber type distribution, fiber type grouping, and the prevalence of atrophic myofibers (≤1,494 µm) in strength-trained (OS) versus endurance-trained (OE) master athletes and compared the results to recreationally active older adults (all >70 yr, OC) and young habitually active references (<30 yr, YC). Immunofluorescent stainings were performed on biopsy samples from vastus lateralis, along with leg press maximal strength and RFD measurements. OS demonstrated similar type II fiber distribution (OS: 52.0 ± 16.4%; YC: 51.1 ± 14.4%), fiber type grouping, maximal strength (OS: 170.0 ± 18.9 kg, YC: 151.0 ± 24.4 kg), and RFD (OS: 3,993 ± 894 N·s, YC: 3,470 ± 1,394 N·s) as young, and absence of atrophic myofibers (OS: 0.2 ± 0.7%; YC: 0.1 ± 0.4%). In contrast, OE and OC exhibited more atrophic fibers (OE: 1.2 ± 1.0%; OC: 1.1 ± 1.4%), more grouped fibers, and smaller proportion of type II fibers (OE: 39.3 ± 11.9%; OC: 35.0 ± 12.4%) than OS and YC (all < 0.05). In conclusion, strength-trained master athletes were characterized by similar muscle morphology as young, which was not the case for recreationally active or endurance-trained old. These results indicate that strength training may preserve type II fibers with advancing age in older men, likely as a result of chronic use of high contractile force generation. Aging is associated with loss of fast-twitch type II myofibers, motor unit remodeling, and grouping of myofibers. This study reveals, for the first time, that strength training preserves neural innervation of type II fibers, resulting in similar myofiber type distribution and grouping in life-long strength-trained master athletes as young moderately active adults. In contrast, life-long endurance-trained master athletes and recreationally active old adults demonstrated higher proportion of type I fibers accompanied by more marked grouping of type I myofibers, and more atrophic fibers compared with strength-trained master athletes and young individuals. Thus, strength training should be utilized as a training modality for preservation of fast-twitch musculature, maximal muscle strength, and rapid force capacity (RFD) with advancing age.
Topics: Male; Humans; Aged; Endurance Training; Muscle Fibers, Skeletal; Aging; Exercise; Muscle Strength; Phenotype; Muscle, Skeletal; Muscle Fibers, Fast-Twitch; Muscle Fibers, Slow-Twitch
PubMed: 37881849
DOI: 10.1152/japplphysiol.00208.2023 -
Journal of the International Society of... Dec 2023It is unclear whether resistance (RT) and concurrent training (CT; resistance plus endurance training) combined with different protein intakes have differential effects...
Effects of 16 weeks of two different high-protein diets with either resistance or concurrent training on body composition, muscular strength and performance, and markers of liver and kidney function in resistance-trained males.
PURPOSE
It is unclear whether resistance (RT) and concurrent training (CT; resistance plus endurance training) combined with different protein intakes have differential effects on muscle hypertrophy, strength, and performance. Therefore, we compared the effects of two high-protein diets (1.6 or 3.2 g.kgd) during 16 weeks of either CT or RT alone in resistance-trained males.
METHODS
Forty-eight resistance-trained males (age: 26 ± 6 yr, body mass index: 25.6 ± 2.9 kg.m) performed 16 weeks (four sessions·w) of CT or RT with either 1.6 g.kgd protein (CT1; = 12; RT1; = 12) or 3.2 g.kgd protein (CT2; = 12; RT2; = 12). Training adaptations were assessed pre-, mid-, and post-intervention.
RESULTS
All measures of performance (endurance, vertical jump, and pull-up), lean mass, muscle strength, and power significantly increased post-intervention in all groups, but peak power gains were greater in RT2 compared with RT1 and CT1 ( < .05). VO significantly increased in both CT groups ( < .001). Select biochemical markers of kidney and liver function significantly increased within the RT2 and CT2 groups ( < .05), however, no between-group differences were apparent ( > .05).
CONCLUSIONS
With the exception of peak power, intake of 1.6 g.kgd of protein appears sufficient to maximize gains in lean mass, muscle strength, performance, and aerobic capacity during both RT and CT without influencing markers of kidney and liver function, indicating this daily protein amount is effective and safely tolerated in young, healthy adults.
Topics: Adult; Male; Humans; Young Adult; Liver; Body Composition; Kidney; Diet, High-Protein; Muscle Strength
PubMed: 37516903
DOI: 10.1080/15502783.2023.2236053 -
PloS One 2023Rotator cuff tendinopathy is a common shoulder disorder in which the primary treatment is resistance exercises. Isometric exercises are being studied for lower limb...
Isometric versus isotonic exercise in individuals with rotator cuff tendinopathy-Effects on shoulder pain, functioning, muscle strength, and electromyographic activity: A protocol for randomized clinical trial.
INTRODUCTION
Rotator cuff tendinopathy is a common shoulder disorder in which the primary treatment is resistance exercises. Isometric exercises are being studied for lower limb tendinopathies but not for rotator cuff tendinopathy. This protocol for a randomized clinical trial aims to compare the effects of two types of exercise (isometric and isotonic) on shoulder pain, functioning, muscle strength, and electromyographic activity in individuals with rotator cuff tendinopathy.
METHODS
Forty-six individuals (18 to 60 years old) with shoulder pain for more than three months and unilateral supraspinatus and/or infraspinatus tendinopathy will participate in this trial. Individuals will be randomized into two exercise groups: isometric or isotonic. The following outcomes will be evaluated before and after the first session and after six weeks of intervention: shoulder pain and functioning; isometric strength of shoulder elevation and lateral and medial rotation; and electromyographic activity of medial deltoid, infraspinatus, serratus anterior, and lower trapezius. Groups will perform stretching and strengthening of periscapular muscles. The isometric group will perform three sets of 32 s, at 70% of maximal isometric strength. The isotonic group will perform concentric and eccentric exercises (2 s for each phase) in three sets of eight repetitions at a load of eight repetition maximum. The total time under tension of 96 s will be equal for both groups, and load will be adjusted in weeks three and five of the protocol. Treatment effect between groups will be analyzed using linear mixed model.
TRIAL REGISTRATION
Trial registration number: Universal Trial Number (UTN) code U1111-1284-7528 and Brazilian Clinical Trials Registry platform-RBR-3pvdvfk.
Topics: Humans; Adolescent; Young Adult; Adult; Middle Aged; Rotator Cuff; Shoulder Pain; Shoulder; Exercise Therapy; Tendinopathy; Muscle Strength; Randomized Controlled Trials as Topic
PubMed: 37956135
DOI: 10.1371/journal.pone.0293457