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Sports Medicine - Open Jul 2023One of the most popular time-efficient training methods when training for muscle hypertrophy is drop sets, which is performed by taking sets to concentric muscle failure...
BACKGROUND
One of the most popular time-efficient training methods when training for muscle hypertrophy is drop sets, which is performed by taking sets to concentric muscle failure at a given load, then making a drop by reducing the load and immediately taking the next set to concentric or voluntary muscle failure. The purpose of this systematic review and meta-analysis was to compare the effects of drop sets over traditional sets on skeletal muscle hypertrophy.
METHODS
This systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The SPORTDiscus and MEDLINE/PubMed databases were searched on April 9, 2022, for all studies investigating the effects of the drop set training method on muscle hypertrophy that meets the predefined inclusion criteria. Comprehensive Meta-Analysis Version 3 (Biostat Inc., Englewood Cliffs, NJ, USA) was used to run the statistical analysis. Publication bias was assessed through visual inspection of the funnel plots for asymmetry and statistically by Egger's regression test with an alpha level of 0.10.
RESULTS
Six studies met the predefined inclusion criteria. The number of participants in the studies was 142 (28 women and 114 men) with an age range of 19.2-27 years. The average sample size was 23.6 ± 10.9 (range 9-41). Five studies were included in the quantitative synthesis. Meta-analysis showed that both the drop set and traditional training groups increased significantly from pre- to post-test regarding muscle hypertrophy (drop set standardized mean difference: 0.555, 95% CI 0.357-0.921, p < 0.0001; traditional set standardized mean difference: 0.437, 95% CI 0.266-0.608, p < 0.0001). No significant between-group difference was found (standardized mean difference: 0.155, 95% CI - 0.199 to - 0.509, p = 0.392).
CONCLUSIONS
The results of this systematic review and meta-analysis indicate that drop sets present an efficient strategy for maximizing hypertrophy in those with limited time for training. There was no significant difference in hypertrophy measurements between the drop set and traditional training groups, but some of the drop set modalities took half to one-third of the time compared with traditional training.
PubMed: 37523092
DOI: 10.1186/s40798-023-00620-5 -
Current Problems in Cardiology Dec 2023Myocardial regeneration has been a topic of interest in literature and research in recent years. An evolving approach reported is glucocorticoid (GC) receptor antagonism... (Review)
Review
Myocardial regeneration has been a topic of interest in literature and research in recent years. An evolving approach reported is glucocorticoid (GC) receptor antagonism and its role in the regeneration of cardiomyocytes. The authors of this study aim to explore the reported literature on GC receptor antagonism and its effects on cardiomyocyte remodeling, hypertrophy, scar formation, and ongoing cardiomyocyte death following cardiac injury. This article overviews cellular biology, mechanisms of action, clinical implications, challenges, and future considerations. The authors of this study conducted a systematic review utilizing the Cochrane methodology and PRISMA guidelines. This study includes data collected and interpreted from 30 peer-reviewed articles from 3 databases with the topic of interest. The mammalian heart has regenerative potential during its embryonic and fetal phases which is lost during its developmental processes. The microenvironment, intrinsic molecular mechanisms, and systemic and external factors impact cardiac regeneration. GCs influence these aspects in some cases. Consequently, GC receptor antagonism is emerging as a promising potential target for stimulating endogenous cardiomyocyte proliferation, aiding in cardiomyocyte regeneration following a cardiac injury such as a myocardial infarction (MI). Experimental studies on neonatal mice and zebrafish have shown promising results with GC receptor ablation (or brief pharmacological antagonism) promoting the survival of myocardial cells, re-entry into the cell cycle, and cellular division, resulting in cardiac muscle regeneration and diminished scar formation. Transient GC receptor antagonism has the potential to stimulate cardiomyocyte regeneration and help prevent the dreaded complications of MI. More trials based on human populations are encouraged to justify their applications and weigh the risk-benefit ratio.
Topics: Animals; Mice; Humans; Myocytes, Cardiac; Receptors, Glucocorticoid; Zebrafish; Cicatrix; Regeneration; Myocardial Infarction; Mammals
PubMed: 37481215
DOI: 10.1016/j.cpcardiol.2023.101986 -
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 -
Journal of Sport and Health Science Jan 2024The aim of this umbrella review was to determine the impact of resistance training (RT) and individual RT prescription variables on muscle mass, strength, and physical... (Review)
Review
PURPOSE
The aim of this umbrella review was to determine the impact of resistance training (RT) and individual RT prescription variables on muscle mass, strength, and physical function in healthy adults.
METHODS
Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we systematically searched and screened eligible systematic reviews reporting the effects of differing RT prescription variables on muscle mass (or its proxies), strength, and/or physical function in healthy adults aged >18 years.
RESULTS
We identified 44 systematic reviews that met our inclusion criteria. The methodological quality of these reviews was assessed using A Measurement Tool to Assess Systematic Reviews; standardized effectiveness statements were generated. We found that RT was consistently a potent stimulus for increasing skeletal muscle mass (4/4 reviews provide some or sufficient evidence), strength (4/6 reviews provided some or sufficient evidence), and physical function (1/1 review provided some evidence). RT load (6/8 reviews provided some or sufficient evidence), weekly frequency (2/4 reviews provided some or sufficient evidence), volume (3/7 reviews provided some or sufficient evidence), and exercise order (1/1 review provided some evidence) impacted RT-induced increases in muscular strength. We discovered that 2/3 reviews provided some or sufficient evidence that RT volume and contraction velocity influenced skeletal muscle mass, while 4/7 reviews provided insufficient evidence in favor of RT load impacting skeletal muscle mass. There was insufficient evidence to conclude that time of day, periodization, inter-set rest, set configuration, set end point, contraction velocity/time under tension, or exercise order (only pertaining to hypertrophy) influenced skeletal muscle adaptations. A paucity of data limited insights into the impact of RT prescription variables on physical function.
CONCLUSION
Overall, RT increased muscle mass, strength, and physical function compared to no exercise. RT intensity (load) and weekly frequency impacted RT-induced increases in muscular strength but not muscle hypertrophy. RT volume (number of sets) influenced muscular strength and hypertrophy.
Topics: Adult; Humans; Resistance Training; Exercise Therapy; Exercise; Hypertrophy; Muscle, Skeletal
PubMed: 37385345
DOI: 10.1016/j.jshs.2023.06.005 -
Somatosensory & Motor Research Jun 2024The benefits of Blood Flow Restriction Therapy (BFRT) have gained attention in recent times. (Meta-Analysis)
Meta-Analysis
Blood flow restriction therapy with exercise are no better than exercise alone in improving athletic performance, muscle strength, and hypertrophy: a systematic review and meta-analysis.
BACKGROUND
The benefits of Blood Flow Restriction Therapy (BFRT) have gained attention in recent times.
OBJECTIVE
This review aimed to evaluate the immediate (up to 24 hours), intermediate (up to 6 weeks), and long term (6-10 weeks) effects of BFRT plus exercises (EX) compared to EX only on athletic performance (sprint and jump performance), muscle strength, and hypertrophy in athletes and physically active population.
METHODS
A literature search was conducted to select randomized controlled trials across four electronic databases from inception till April 2021. The search yielded twenty-seven studies in total.
RESULTS
Based on eligibility criteria, twenty-one studies were analyzed. No differences were found between both groups for immediate (standardized mean difference [SMD] -0.02, 95% confidence interval [CI] -0.31, 0.27) and long-term effects (SMD -0.30, 95%CI -0.90, 0.30) on sprint performance. For jump performance, no significant effect was observed immediately (SMD -0.02 (95% CI -1.06, 1.02) and long term (SMD -0.40 (95% CI -1.46, 0.67). Similarly, muscle torque at intermediate (SMD 0.90 (95% CI -1.01, 2.81) and long term (SMD -0.54 (95% CI -1.19, 0.12), muscle strength at intermediate (SMD 1.12 (95% CI 0.20, 2.04), and long term (SMD -0.07 (95% CI -0.56, 0.42) also showed non-significant effects. Muscle hypertrophy at intermediate (SMD 0.16 (95% CI -0.31, 0.63) and long term (SMD -0.20 (95% CI -0.90, 0.50) were not statistically significant.
CONCLUSIONS
There was no significant difference observed in BFRT plus EX group compared to the EX-group on athletic performance, muscle strength, and muscle hypertrophy.
Topics: Humans; Muscle Strength; Athletic Performance; Blood Flow Restriction Therapy; Muscle, Skeletal; Hypertrophy; Exercise Therapy
PubMed: 36825612
DOI: 10.1080/08990220.2023.2181328