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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 -
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 -
Journal of Applied Physiology... Dec 2023Hormonal changes around ovulation divide the menstrual cycle (MC) into the follicular and luteal phases. In addition, oral contraceptives (OCs) have active (higher... (Meta-Analysis)
Meta-Analysis Review
Hormonal changes around ovulation divide the menstrual cycle (MC) into the follicular and luteal phases. In addition, oral contraceptives (OCs) have active (higher hormone) and placebo phases. Although there are some MC-based effects on various physiological outcomes, we found these differences relatively subtle and difficult to attribute to specific hormones, as estrogen and progesterone fluctuate rather than operating in a complete on/off pattern as observed in cellular or preclinical models often used to substantiate human data. A broad review reveals that the differences between the follicular and luteal phases and between OC active and placebo phases are not associated with marked differences in exercise performance and appear unlikely to influence muscular hypertrophy in response to resistance exercise training. A systematic review and meta-analysis of substrate oxidation between MC phases revealed no difference between phases in the relative carbohydrate and fat oxidation at rest and during acute aerobic exercise. Vascular differences between MC phases are also relatively small or nonexistent. Although OCs can vary in composition and androgenicity, we acknowledge that much more work remains to be done in this area; however, based on what little evidence is currently available, we do not find compelling support for the notion that OC use significantly influences exercise performance, substrate oxidation, or hypertrophy. It is important to note that the study of females requires better methodological control in many areas. Previous studies lacking such rigor have contributed to premature or incorrect conclusions regarding the effects of the MC and systemic hormones on outcomes. While we acknowledge that the evidence in certain research areas is limited, the consensus view is that the impact of the MC and OC use on various aspects of physiology is small or nonexistent.
Topics: Female; Humans; Contraceptives, Oral; Menstrual Cycle; Hormones; Progesterone; Hypertrophy
PubMed: 37823207
DOI: 10.1152/japplphysiol.00346.2023 -
BMC Sports Science, Medicine &... Aug 2023The effectiveness of strength training with free-weight vs. machine equipment is heavily debated. Thus, the purpose of this meta-analysis was to summarize the data on...
BACKGROUND
The effectiveness of strength training with free-weight vs. machine equipment is heavily debated. Thus, the purpose of this meta-analysis was to summarize the data on the effect of free-weight versus machine-based strength training on maximal strength, jump height and hypertrophy.
METHODS
The review was conducted in accordance with the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines, and the systematic search of literature was conducted up to January 1, 2023. Studies that directly compared free-weight vs. machine-based strength training for a minimum of 6 weeks in adults (18-60 yrs.) were included.
RESULTS
Thirteen studies (outcomes: maximal strength [n = 12], jump performance [n = 5], muscle hypertrophy [n = 5]) with a total sample of 1016 participants (789 men, 219 women) were included. Strength in free-weight tests increased significantly more with free-weight training than with machines (SMD: -0.210, CI: -0.391, -0.029, p = 0.023), while strength in machine-based tests tended to increase more with machine training than with free-weights (SMD: 0.291, CI: -0.017, 0.600, p = 0.064). However, no differences were found between modalities in direct comparison (free-weight strength vs. machine strength) for dynamic strength (SMD: 0.084, CI: -0.106, 0.273, p = 0.387), isometric strength (SMD: -0.079, CI: -0.432, 0.273, p = 0.660), countermovement jump (SMD: -0.209, CI: -0.597, 0.179, p = 0.290) and hypertrophy (SMD: -0.055, CI: -0.397, 0.287, p = 0.751).
CONCLUSION
No differences were detected in the direct comparison of strength, jump performance and muscle hypertrophy. Current body of evidence indicates that strength changes are specific to the training modality, and the choice between free-weights and machines are down to individual preferences and goals.
PubMed: 37582807
DOI: 10.1186/s13102-023-00713-4 -
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 -
Sports Medicine (Auckland, N.Z.) Jan 2024Resistance exercise training is widely used by general and athletic populations to increase skeletal muscle hypertrophy, power and strength. Endogenous sex hormones... (Meta-Analysis)
Meta-Analysis
The Effect of Hormonal Contraceptive Use on Skeletal Muscle Hypertrophy, Power and Strength Adaptations to Resistance Exercise Training: A Systematic Review and Multilevel Meta-analysis.
BACKGROUND
Resistance exercise training is widely used by general and athletic populations to increase skeletal muscle hypertrophy, power and strength. Endogenous sex hormones influence various bodily functions, including possibly exercise performance, and may influence adaptive changes in response to exercise training. Hormonal contraceptive (HC) use modulates the profile of endogenous sex hormones, and therefore, there is increasing interest in the impact, if any, of HC use on adaptive responses to resistance exercise training.
OBJECTIVE
Our aim is to provide a quantitative synthesis of the effect of HC use on skeletal muscle hypertrophy, power and strength adaptations in response to resistance exercise training.
METHODS
A systematic review with meta-analysis was conducted on experimental studies which directly compared skeletal muscle hypertrophy, power and strength adaptations following resistance exercise training in hormonal contraceptive users and non-users conducted before July 2023. The search using the online databases PUBMED, SPORTDiscus, Web of Science, Embase and other supplementary search strategies yielded 4669 articles, with 8 articles (54 effects and 325 participants) meeting the inclusion criteria. The methodological quality of the included studies was assessed using the "Tool for the assessment of study quality and reporting in exercise".
RESULTS
All included studies investigated the influence of oral contraceptive pills (OCP), with no study including participants using other forms of HC. The articles were analysed using a meta-analytic multilevel maximum likelihood estimator model. The results indicate that OCP use does not have a significant effect on hypertrophy [0.01, 95% confidence interval (CI) [- 0.11, 0.13], t = 0.14, p = 0.90), power (- 0.04, 95% CI [- 0.93, 0.84], t = - 0.29, p = 0.80) or strength (0.10, 95% CI [- 0.08, 0.28], t = 1.48, p = 0.20).
DISCUSSION
Based on the present analysis, there is no evidence-based rationale to advocate for or against the use of OCPs in females partaking in resistance exercise training to increase hypertrophy, power and/or strength. Rather, an individualised approach considering an individual's response to OCPs, their reasons for use and menstrual cycle history may be more appropriate.
REGISTRATION
The review protocol was registered on PROSPERO (ID number and hyperlink: CRD42022365677).
Topics: Female; Humans; Contraceptives, Oral; Gonadal Steroid Hormones; Hypertrophy; Muscle Strength; Muscle, Skeletal; Resistance Training
PubMed: 37755666
DOI: 10.1007/s40279-023-01911-3 -
Journal of Strength and Conditioning... Jul 2024Ramos-Campo, DJ, Benito-Peinado, PJ, Caravaca, LA, Rojo-Tirado, MA, and Rubio-Arias, JÁ. Efficacy of split versus full-body resistance training on strength and muscle... (Meta-Analysis)
Meta-Analysis
Ramos-Campo, DJ, Benito-Peinado, PJ, Caravaca, LA, Rojo-Tirado, MA, and Rubio-Arias, JÁ. Efficacy of split versus full-body resistance training on strength and muscle growth: a systematic review with meta-analysis. J Strength Cond Res 38(7): 1330-1340, 2024-No previous study has systematically compared the effect of 2 resistance training routines commonly used to increase muscle mass and strength (i.e., split [Sp] and full-body [FB] routines). Our objective was to conduct a systematic review and meta-analysis following PRISMA guidelines to compare the effects on strength gains and muscle growth in healthy adults. 14 studies (392 subjects) that compared Sp and FB routines in terms of strength adaptations and muscle growth were included. Regarding the effects of the Sp or FB routine on both bench press and lower limbs strength, the magnitude of the change produced by both routines was similar (bench press: mean difference [MD] = 1.19; [-1.28, 3.65]; p = 0.34; k = 14; lower limb: MD = 2.47; [-2.11, 7.05]; p = 0.29; k = 14). Concerning the effect of the Sp vs. FB routine on muscle growth, similar effects were observed after both routines in the cross-sectional area of the elbow extensors (MD = 0.30; [-2.65, 3.24]; p = 0.84; k = 4), elbow flexors (MD = 0.17; [-2.54, 2.88]; p = 0.91; k = 5), vastus lateralis (MD = -0.08; [-1.82, 1.66]; p = 0.93; k = 5), or lean body mass (MD = -0.07; [-1.59, 1.44]; p = 0.92; k = 6). In conclusion, the present systematic review and meta-analysis provides solid evidence that the use of Sp or FB routines within a resistance training program does not significantly impact either strength gains or muscle hypertrophy when volume is equated. Consequently, individuals are free to confidently select a resistance training routine based on their personal preferences.
Topics: Humans; Resistance Training; Muscle Strength; Muscle, Skeletal; Lower Extremity; Muscle Development
PubMed: 38595233
DOI: 10.1519/JSC.0000000000004774 -
Hypertension (Dallas, Tex. : 1979) Nov 2023Masked hypertension (MH) occurs when office blood pressure is normal, but hypertension is confirmed using out-of-office blood pressure measures. Hypertension is a risk... (Meta-Analysis)
Meta-Analysis Review
Masked hypertension (MH) occurs when office blood pressure is normal, but hypertension is confirmed using out-of-office blood pressure measures. Hypertension is a risk factor for subclinical cardiovascular outcomes, including left ventricular hypertrophy, increased left ventricular mass index, carotid intima media thickness, and pulse wave velocity. However, the risk factors for ambulatory blood pressure monitoring defined MH and its association with subclinical cardiovascular outcomes are unclear. A systematic literature search on 9 databases included English publications from 1974 to 2023. Pediatric MH prevalence was stratified by disease comorbidities and compared with the general pediatric population. We also compared the prevalence of left ventricular hypertrophy, and mean differences in left ventricular mass index, carotid intima media thickness, and pulse wave velocity between MH versus normotensive pediatric patients. Of 2199 screened studies, 136 studies (n=28 612; ages 4-25 years) were included. The prevalence of MH in the general pediatric population was 10.4% (95% CI, 8.00-12.80). Compared with the general pediatric population, the risk ratio (RR) of MH was significantly greater in children with coarctation of the aorta (RR, 1.91), solid-organ or stem-cell transplant (RR, 2.34), chronic kidney disease (RR, 2.44), and sickle cell disease (RR, 1.33). MH patients had increased risk of subclinical cardiovascular outcomes compared with normotensive patients, including higher left ventricular mass index (mean difference, 3.86 g/m [95% CI, 2.51-5.22]), left ventricular hypertrophy (odds ratio, 2.44 [95% CI, 1.50-3.96]), and higher pulse wave velocity (mean difference, 0.30 m/s [95% CI, 0.14-0.45]). The prevalence of MH is significantly elevated among children with various comorbidities. Children with MH have evidence of subclinical cardiovascular outcomes, which increases their risk of long-term cardiovascular disease.
Topics: Humans; Child; Masked Hypertension; Hypertrophy, Left Ventricular; Blood Pressure Monitoring, Ambulatory; Carotid Intima-Media Thickness; Prevalence; Pulse Wave Analysis; Hypertension; Blood Pressure
PubMed: 37737026
DOI: 10.1161/HYPERTENSIONAHA.123.20967 -
Journal of Clinical Neuromuscular... Dec 2023Isaac syndrome (IS) is a condition characterized by peripheral nerve hyperexcitability caused by voltage-gated potassium channel (VGKC)-complex antibodies. Muscle...
OBJECTIVES
Isaac syndrome (IS) is a condition characterized by peripheral nerve hyperexcitability caused by voltage-gated potassium channel (VGKC)-complex antibodies. Muscle twitching, stiffness, hypertrophy, and dysautonomic characteristics, such as hyperhidrosis, are common manifestations. The syndrome can be autoimmune or paraneoplastic, with thymoma being a common cause of paraneoplastic IS. Furthermore, this condition could be handed down from one generation to another. However, there is limited information regarding outcomes, relapses, associated syndromes, associated malignancies (other than thymoma), and treatment options. Despite its rarity, there remains a need for effective management strategies for patients with IS. To address this gap, we conducted a systematic review to summarize the most common and effective treatments of IS in immunomodulatory agents and symptomatic medications, as well as to describe outcomes, relapses, and associated malignancies. Altogether, this review serves to guide clinical practice recommendations for IS and highlight areas for further research.
METHODS
We used the Preferred Reporting Items for Systematic Reviews and Meta-Analyses protocol to conduct a systematic review of cases reposted through the PubMed and Google Scholar databases. The terms "Isaac Syndrome" and "Acquired Neuromyotonia" were used. The Joanna Briggs Institute's critical appraisal tool was used to evaluate the quality of the included studies.
RESULTS
We identified 61 case reports and 4 case series, comprising a total of 70 patients with IS (mean age at onset: 42.5 ± 18 years, and 69% were males). Fourteen cases reported relapses. Thymoma was the most common malignancy associated with IS, followed by lymphoma. Among various serum antibodies, voltage-gated potassium channel-complex antibodies were the most reported antibodies elevated in IS (reported in 38 patients and elevated in 21 patients [55.2%]), followed by acetylcholine ganglionic receptor antibodies, which were reported in 30% of patients (n = 21) and were elevated in 5 cases. The most common electromyography findings were myokymic discharges (n = 22), followed by fasciculations (n = 21) and neuromyotonia (n = 19). For treatment, combining anticonvulsants such as carbamazepine with immunotherapy therapy showed the best results in controlling the symptoms. Among immunotherapy therapies, the combination of plasma exchange plus intravenous high-dose steroids achieved the best results in the acute treatment of IS ([n = 6], with improvement noted in 83.3% [n = 5] of cases). Among the symptomatic treatments with anticonvulsants, carbamazepine was the most efficacious anticonvulsant in treatment of IS, with an average effective dosing of 480 mg/day (carbamazepine was used in 32.3% of acute treatment strategies [n = 23], with improvement noted in 73.9% [n = 17] of cases).
CONCLUSIONS
IS a rare neuromuscular syndrome that tends to affect middle-aged men. These patients should be screened for thymoma and other malignancies such as lymphomas. The management of IS symptoms can be challenging, but based on our review, the combination of multiple immunosuppressives such as IV steroids and plasmapheresis with anticonvulsants such as carbamazepine seems to achieve the best results.
Topics: Male; Middle Aged; Humans; Female; Isaacs Syndrome; Thymoma; Anticonvulsants; Thymus Neoplasms; Autoantibodies; Potassium Channels, Voltage-Gated; Carbamazepine; Receptors, Cholinergic; Steroids; Recurrence
PubMed: 37962197
DOI: 10.1097/CND.0000000000000460 -
Sports Medicine (Auckland, N.Z.) Feb 2024Many sports require maximal strength and endurance performance. Concurrent strength and endurance training can lead to suboptimal training adaptations. However, how... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Many sports require maximal strength and endurance performance. Concurrent strength and endurance training can lead to suboptimal training adaptations. However, how adaptations differ between males and females is currently unknown. Additionally, current training status may affect training adaptations.
OBJECTIVE
We aimed to assess sex-specific differences in adaptations in strength, power, muscle hypertrophy, and maximal oxygen consumption ( O) to concurrent strength and endurance training in healthy adults. Second, we investigated how training adaptations are influenced by strength and endurance training status.
METHODS
A systematic review and meta-analysis was conducted according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, and a Cochrane risk of bias was evaluated. ISI Web of science, PubMed/MEDLINE, and SPORTDiscus databases were searched using the following inclusion criteria: healthy adults aged 18-50 years, intervention period of ≥ 4 weeks, and outcome measures were defined as upper- and lower-body strength, power, hypertrophy, and/or O. A meta-analysis was performed using a random-effects model and reported in standardized mean differences.
RESULTS
In total, 59 studies with 1346 participants were included. Concurrent training showed blunted lower-body strength adaptations in males, but not in females (male: - 0.43, 95% confidence interval [- 0.64 to - 0.22], female: 0.08 [- 0.34 to 0.49], group difference: P = 0.03). No sex differences were observed for changes in upper-body strength (P = 0.67), power (P = 0.37), or O (P = 0.13). Data on muscle hypertrophy were insufficient to draw any conclusions. For training status, untrained but not trained or highly trained endurance athletes displayed lower O gains with concurrent training (P = 0.04). For other outcomes, no differences were found between untrained and trained individuals, both for strength and endurance training status.
CONCLUSIONS
Concurrent training results in small interference for lower-body strength adaptations in males, but not in females. Untrained, but not trained or highly trained endurance athletes demonstrated impaired improvements in O following concurrent training. More studies on females and highly strength-trained and endurance-trained athletes are warranted.
CLINICAL TRIAL REGISTRATION
PROSPERO: CRD42022370894.
Topics: Adult; Humans; Male; Female; Endurance Training; Physical Endurance; Athletes; Sports; Hypertrophy; Muscle Strength; Resistance Training
PubMed: 37847373
DOI: 10.1007/s40279-023-01943-9