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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 -
Nutrients Apr 2023The purpose of this paper was to carry out a systematic review with a meta-analysis of randomized controlled trials that examined the combined effects of resistance... (Meta-Analysis)
Meta-Analysis Review
The purpose of this paper was to carry out a systematic review with a meta-analysis of randomized controlled trials that examined the combined effects of resistance training (RT) and creatine supplementation on regional changes in muscle mass, with direct imaging measures of hypertrophy. Moreover, we performed regression analyses to determine the potential influence of covariates. We included trials that had a duration of at least 6 weeks and examined the combined effects of creatine supplementation and RT on site-specific direct measures of hypertrophy (magnetic resonance imaging (MRI), computed tomography (CT), or ultrasound) in healthy adults. A total of 44 outcomes were analyzed across 10 studies that met the inclusion criteria. A univariate analysis of all the standardized outcomes showed a pooled mean estimate of 0.11 (95% Credible Interval (CrI): -0.02 to 0.25), providing evidence for a very small effect favoring creatine supplementation when combined with RT compared to RT and a placebo. Multivariate analyses found similar small benefits for the combination of creatine supplementation and RT on changes in the upper and lower body muscle thickness (0.10-0.16 cm). Analyses of the moderating effects indicated a small superior benefit for creatine supplementation in younger compared to older adults (0.17 (95%CrI: -0.09 to 0.45)). In conclusion, the results suggest that creatine supplementation combined with RT promotes a small increase in the direct measures of skeletal muscle hypertrophy in both the upper and lower body.
Topics: Humans; Aged; Creatine; Resistance Training; Hypertrophy; Muscles; Dietary Supplements
PubMed: 37432300
DOI: 10.3390/nu15092116 -
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 -
Voprosy Pitaniia 2023Muscle weakness and atrophy of the quadriceps muscle after anterior cruciate ligament reconstruction may persist for up to 6 months after surgery and cause re-injury to...
Muscle weakness and atrophy of the quadriceps muscle after anterior cruciate ligament reconstruction may persist for up to 6 months after surgery and cause re-injury to the ipsilateral or contralateral limbs. Many authors state that adequate nutritional status during the rehabilitation period can contribute to faster postoperative recovery of muscle mass and strength of the lower limb, be an adjunct to exercise, or serve an alternative treatment strategy. of the research was to conduct a systematic review of the literature and evaluate the degree of influence of dietary supplements on muscle mass and strength of the operated limb after reconstruction of the anterior cruciate ligament (ACL). . The search for articles was carried out in international databases PubMed, Google Scholar, Cochrane Library. The time frame of the search was 22 years. To be included in the review, studies had to meet the PICOS criteria: participants were men and women over 18 years of age after ACL reconstruction; intervention - supplementation after and/or before and after ACL reconstruction; comparison - placebo group or no supplementary interventions; results - assessment of the dynamics of changes in muscle mass (cross-sectional area, muscle thickness or size of skeletal muscle fibers) and / or maximum strength (dynamic or isometric) of the operated limb; research design - randomized controlled trials (RCT). The quality of selected RCTs was assessed using the Cochrane Collaboration Risk of Bias (RoB 2) tool. . A total of 1397 articles were found after searching in the databases. This systematic review included 6 RCTs with a total number of patients 186. The following dietary supplements were used: leucine - 1 article, glucosam ine - 1 article, creatine - 1 article, vitamins E and C - 2 articles. One study evaluated the effect of whey protein supplementation in combination with neuromuscular electrical stimulation on isometric strength of the operated limb. When comparing the data of 3 groups in the pre- and postoperative periods, there were no statistically significant differences between the groups. When considering the protocols for taking dietary supplements based on creatine, glucosamine, vitamins E and C, none of the studies demonstrated statistically significant improvements in the parameters of maximum strength or muscle hypertrophy of the operated limb in the main groups compared with the control groups. Also, no results have been obtained indicating that these dietary supplements can slow down muscl e atrophy after surgery. In another study that evaluated the effect of leucine supplementation, by the end of the rehabilitation program, the muscle strength of the operated limb tended to increase more in the leucine group than in the placebo group, but without a statistically significant difference. At 10 cm from the patella, the femoral circumference of the operated limb in the leucine group increased more than in the placebo group, and the differences were statistically significant (р=0.009). Two studies were rated as high risk of bias, three as moderate risk, and one as low risk. . None of the supplements used had a statistically significant effect on the muscle strength of the operated limb after ACL reconstru ction. In terms of thigh muscle hypertrophy, the only significant improvement was associated with leucine supplementation and an increase in thigh circumference at a distance of 10 cm from the patella.
Topics: Male; Female; Humans; Adolescent; Adult; Anterior Cruciate Ligament Injuries; Whey Proteins; Creatine; Leucine; Quadriceps Muscle; Atrophy; Dietary Supplements; Anterior Cruciate Ligament Reconstruction; Vitamins; Randomized Controlled Trials as Topic
PubMed: 37346024
DOI: 10.33029/0042-8833-2023-92-2-87-96 -
Journal of Functional Morphology and... Apr 2023Emerging evidence indicates that the use of low-load resistance training in combination with blood flow restriction (LL-BFR) can be an effective method to elicit... (Review)
Review
Emerging evidence indicates that the use of low-load resistance training in combination with blood flow restriction (LL-BFR) can be an effective method to elicit increases in muscle size, with most research showing similar whole muscle development of the extremities compared to high-load (HL) training. It is conceivable that properties unique to LL-BFR such as greater ischemia, reperfusion, and metabolite accumulation may enhance the stress on type I fibers during training compared to the use of LLs without occlusion. Accordingly, the purpose of this paper was to systematically review the relevant literature on the fiber-type-specific response to LL-BFR and provide insights into future directions for research. A total of 11 studies met inclusion criteria. Results of the review suggest that the magnitude of type I fiber hypertrophy is at least as great, and sometimes greater, than type II hypertrophy when performing LL-BFR. This finding is in contrast to HL training, where the magnitude of type II fiber hypertrophy tends to be substantially greater than that of type I myofibers. However, limited data directly compare training with LL-BFR to nonoccluded LL or HL conditions, thus precluding the ability to draw strong inferences as to whether the absolute magnitude of type I hypertrophy is indeed greater in LL-BFR vs. traditional HL training. Moreover, it remains unclear as to whether combining LL-BFR with traditional HL training may enhance whole muscle hypertrophy via greater increases in type I myofiber cross-sectional area.
PubMed: 37218848
DOI: 10.3390/jfmk8020051 -
Frontiers in Medicine 2023To systematically evaluate the effects of resistance training (RT) on muscle strength and muscle hypertrophy in elderly cancer patients, and to provide dose-response...
OBJECTIVE
To systematically evaluate the effects of resistance training (RT) on muscle strength and muscle hypertrophy in elderly cancer patients, and to provide dose-response relationships of RT variables that could improve muscle strength and morphology in elderly cancer patients.
METHOD
The Review Manager 5.3 was applied to analyze the 12 literatures (616 participants) through random or fixed effects model and global effect size to examine upper limb strength, lower extremity strength, and muscle hypertrophy. Sub-group analysis was made on five variables: the total number of repeated training times/week, load intensity, exercise frequency/week, exercise duration and gender. This study also examines the heterogeneity and publication bias.
RESULTS
Twelve literatures (616 participants, 60-80 years) were included in meta-analysis. RT significantly increased the upper limb muscular strength (SMD = 0.51, 95% CI: 0.10-0.93; = 2.41; = 0.02) and lower extremity strength (SMD = 0.48, 95% CI: 0.28-0.67; = 4.82; < 0.00001), but had no significant effect on muscle morphology(SMD = 0.21, 95% CI: 0.01-0.42; = 1.88; = 0.06). In subgroup analysis for lower extremity muscle strength in elderly male cancer patients, it was found that male intensity of 70-90%1RM, volume of 400-500 times per week, frequencies of 3 times per week, and session of 12-24 weeks, revealed the greatest effect. Funnel plot of the three studies shows that the results were reliable, and no publication bias was found.
CONCLUSION
RT had medium effects on improving muscle strength in elderly cancer patients, but it is not effective in improving muscle hypertrophy. In addition, when RT is performed, different training protocols can have an effect on the growth of muscle strength. Therefore, a lower extremity training protocol with a training intensity of 70-90% 1RM, a total of 400-500 repetitions per week, 3 times per week, and an exercise session of 12-24 weeks is most effective in improving lower extremity strength in elderly male cancer patients.
PubMed: 37089606
DOI: 10.3389/fmed.2023.1049248 -
Scientific Reports Mar 2023A systematic review and meta-analysis was conducted to determine the effects of resistance training under hypoxic conditions (RTH) on muscle hypertrophy and strength... (Meta-Analysis)
Meta-Analysis
A systematic review and meta-analysis was conducted to determine the effects of resistance training under hypoxic conditions (RTH) on muscle hypertrophy and strength development. Searches of PubMed-Medline, Web of Science, Sport Discus and the Cochrane Library were conducted comparing the effect of RTH versus normoxia (RTN) on muscle hypertrophy (cross sectional area (CSA), lean mass and muscle thickness) and strength development [1-repetition maximum (1RM)]. An overall meta-analysis and subanalyses of training load (low, moderate or high), inter-set rest interval (short, moderate or long) and severity of hypoxia (moderate or high) were conducted to explore the effects on RTH outcomes. Seventeen studies met inclusion criteria. The overall analyses showed similar improvements in CSA (SMD [CIs] = 0.17 [- 0.07; 0.42]) and 1RM (SMD = 0.13 [0.0; 0.27]) between RTH and RTN. Subanalyses indicated a medium effect on CSA for longer inter-set rest intervals and a small effect for moderate hypoxia and moderate loads favoring RTH. Moreover, a moderate effect for longer inter-set rest intervals and a trivial effect for severe hypoxia and moderate loads favoring RTH was found on 1RM. Evidence suggests that RTH employed with moderate loads (60-80% 1RM) and longer inter-set rest intervals (≥ 120 s) enhances muscle hypertrophy and strength compared to normoxia. The use of moderate hypoxia (14.3-16% FiO) seems to be somewhat beneficial to hypertrophy but not strength. Further research is required with greater standardization of protocols to draw stronger conclusions on the topic.
Topics: Humans; Animals; Resistance Training; Gastropoda; Hypertrophy; Hypoxia; Muscles
PubMed: 36871095
DOI: 10.1038/s41598-023-30808-4 -
International Journal of Environmental... Feb 2023This study aimed to investigate the effects of eccentric cycling (ECC) training on performance, physiological, and morphological parameters in comparison to concentric... (Meta-Analysis)
Meta-Analysis Review
This study aimed to investigate the effects of eccentric cycling (ECC) training on performance, physiological, and morphological parameters in comparison to concentric cycling (CON) training. Searches were conducted using PubMed, Embase, and ScienceDirect. Studies comparing the effect of ECC and CON training regimens on performance, physiological, and/or morphological parameters were included. Bayesian multilevel meta-analysis models were used to estimate the population's mean difference between chronic responses from ECC and CON training protocols. Group levels and meta-regression were used to evaluate the specific effects of subjects and study characteristics. Fourteen studies were included in this review. The meta-analyses showed that ECC training was more effective in increasing knee extensor strength, vastus lateralis fiber cross-sectional area, and six-minute walking distance compared to CON. Moreover, ECC was as effective as CON in decreasing body fat percentage. CON was more effective in increasing V˙O2max and peak power output attained during concentric incremental tests. However, group-level analyses revealed that ECC was more effective than CON in improving V˙O2max in patients with cardiopulmonary diseases. ECC is a viable modality for exercise interventions aiming to improve parameters of muscle strength, hypertrophy, functional capacity, aerobic power, and body composition, with more advantages than CON training in improving neuromuscular variables.
Topics: Humans; Bayes Theorem; Muscle Strength; Quadriceps Muscle; Knee; Knee Joint; Adaptation, Physiological; Muscle, Skeletal; Resistance Training
PubMed: 36833557
DOI: 10.3390/ijerph20042861