Effects of Advanced Resistance Training Systems on Muscle Hypertrophy and Strength in Recreationally Trained Adults: A Systematic Review and Meta-Analysis

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Overall, the submission intitled: Effects of Advanced Resistance Training Systems on Muscle Hypertrophy and Strength in Recreationally Trained Adults: A Systematic Review and Meta‑Analysis was very well thought out and explained. The proper guidelines were followed in the lit review and were current with PRISMA guidelines. The results were clear (however so formatting of Forest plots could be better so it can be read and seen more, straight line vertically instead of diamonds down the middle). Breaking down each of the variables and analyzing them separately was very well done as they address each potential claim by each technique.  Limitations of the review were properly addressed mainly not in the review itself but of the studies that are primarily out there. Nothing you can do about samples size and population chosen in the studies. One analysis that was left out and can be utilized not as much in the methods section but can clear up the discussion of which better would be to report an aggregate effect size for each of the training systems to compare between the training systems. There was no difference in effect between hypertrophy and traditional but in the case of strength can we tease out which method might have a larger effect size than another. For example, in the practical application section I could only do one of these advanced systems to train strength in one better than the other. Can you answer that question? 

Author Response

Response to Reviewer 1

We sincerely thank the reviewer for the positive and constructive evaluation of our manuscript. We greatly appreciate the recognition of the methodological rigor, adherence to PRISMA guidelines, and clarity of the results.

Comment 1: Formatting of forest plots
Response:
We agree with the reviewer’s observation. The forest plots have been reformatted to improve readability, with a clearer vertical reference line and standardized graphical elements.

Comment 2: Aggregate effect sizes for each advanced training system
Response:

We thank the reviewer for this valuable suggestion. In response, we have added a dedicated subsection in the Discussion and expanded the Practical Applications section to report and interpret the aggregate effect sizes for each advanced method. This addition clarifies the comparative strength‑related impact of the different systems.

Specifically, we now highlight that velocity‑based training and eccentric‑overload methods demonstrated the largest strength‑related effect sizes, followed by rest‑pause training, whereas drop sets, tempo‑controlled lifting, and cluster‑type configurations produced strength adaptations comparable to traditional multiple‑set training when volume and effort were matched.

This addition directly addresses the reviewer’s question regarding which advanced method may be preferable when only one can be implemented for strength‑focused programming.

We appreciate the reviewer’s insightful feedback, which has strengthened the clarity and practical relevance of the manuscript.

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

Effects of Advanced Resistance Training Systems on Muscle Hypertrophy and Strength in Recreationally Trained Adults: A Systematic Review and Meta-Analysis

 

Massive Structural and Formatting Woes

The manuscript, sadly, resembles a rough draft, riddled with glaring formatting fails, blocking a proper read through.

 

Page numbering and Text Oddities: Pages 4, 5, 6, plus bits of others, showcase just sequential numberslike 144, 145, 146, it seems. This likely stems from a wonky submission system, or maybe some formatting mistakes. All text needs to flow, sequentially. The abstract ends abruptly on page one and then introduction starts on page 2. Erase them placeholder numbers, all of them!

 

Incomplete bits, all over the place: Major parts of the systematic review are MIA, or simply not finished:

 

Methods, where's the methods?: This section isn't here, it's missing. The text just jumps from Introduction ending in middle of the sentence on page 3 right to 3. Results. A whole "Methods" bit must detail PICO strategy, search ways (databases, dates, search strings), study picks, how data gets taken out, risk of bias check, stats stuff for meta-analysis like the models, how heterogeneous it is, plus a plan to check publication bias, and how moderator analysis going to go; must all be there before the Results get told.

 

Discussion and Conclusion, needing more work: Included are discussion scraps (e.g. pages 19-22 "4.3 Strength vs hypertrophy adaptations") mixed with some more number stuff. A full Discussion, properly structured, is required with a whole conclusion section.

Figures and Tables: Figures 1 3 4 alongside Tables 1 to 4 are mentioned but missing from the displayed content. Provide these as distinct highresolution files or insert them appropriately within the text.

 

Action Required: The manuscript requires restructuring aligning it with the typical IMRaD format including: Abstract Keywords Introduction Materials and Methods Results Discussion Conclusions and References. Delete placeholder numerals and verify each section's completeness.

 

Abstract:

Needs Standardization: The abstract needs formatting incorporating Background Methods Results and Conclusions per the journal's guidelines.

Clarity: That sentance "Across models 2τ2 estimates were close to zero showing small between study diversity" is fine perhaps clarify the models used say like "In both random effects and fixed effects models.

Conclusion Improvement: The ending conclusion is well put but can be slightly enhanced to emphasize its evidence-based and goal-driven purpose.

Revised Conclusion Example:

"Conclusions: Advanced resistance training methods may be efficiently used for adults with some experience with recreational training offering some gains in maximum strength with no detriment to growth. There's not enough proof to claim overall superiority for muscle enlargement so applications should match particular training targets (such as Focusing on individual needs instead of aiming for universally optimal muscle gains includes considerations like, strength's emphasis, constraints related to logistics, and personal choices.

 

Introduction:

The introduction covers most things, though could be neater. It moves from general resistance training advantages to more complex systems naturally. Notably, the paragraph beginning with "Despite extensive literature..." (lines 113-121) needs to be highlighted, its a very important point for the whole review!

 

Population Focused:

Good decision to keep it about recreationally trained adults, aged 18-45 years. Make sure to clearly state this part of your PICO as an goal.

 

Recommendation:

Stick a clearer statement of the review's purposes right at the end of the intro. Like this perhaps "This systematic review and meta-analysis will thus compare the influence advanced resistance training versus standard multiple-set training, looking specifically at muscle growth and peak strength amongst recreationally trained adults. Training type, the total work completed, and nearness to failure are other factors the review will look at.

 

Materials and Methods (Absent section – HUGE!)

You've gotta build this from scratch. Things to add:

 

1. The Protocol and Registration: Make sure you put in the preregistration info (e. g. PROSPERO ID)
2. Eligibility (PICO): Explain Population, Intervention, Comparator, Outcomes, and study Design clearly.

3.

Information Sources & Search Strategy: Databases need listing like PubMed Scopus, Web of Science etc plus search dates, also include a sample search string in a separate appendix.

 

Study Selection Process: The process should get a description, for example using Rayyan and dual screening, of that sort.

 

Data Extraction: Detail the extracted variables such as author, year, population details, also the characteristics of the intervention and outcomes.

 

Risk of Bias Assessment: Specifying the tool like ROB2 and it’s application needs explanation.

 

Statistical Analysis (MetaAnalysis): Detail the software used such as R with a metafor package would do. Justify using Hedges' g. Explain, in depth, the meta-analytic model for example saying, "A restricted maximum-likelihood estimator random-effects model was employed because there was anticipation of clinical and methodological heterogeneity." Also, describe in details the heterogeneity assessment using I², τ², and Q-test. Provide an explanation regarding the usage of Knapp-Hartung adjustments. And give details about the moderator analysis method meta-regression or the analysis with a subgroup. Plans for assessing publication bias like with funnel plots, Egger's test, which are, currently, absent from results and it MUST be included.

 

Results

Study Selection: PRISMA flow diagram (Figure 1) is mentioned yet not shown. It is something to include. Study Characteristics: Tables 1-3 are generally good but they don't appear in the text fully. Make sure they are whole and correctly formatted. Risk of Bias: Table 4 is fine how it is. The summary seems acceptable.

Meta-Analysis Findings: The stated stats g equals 0.159, 0.351, 0.046 is okay. But, the text mention Figures 3 and 4 forest plots that is not there. Those plots, well, they are necessary. Moreover, the outcomes from moderator analyzes method, volume equivalence, and the close-ness to failure, it's in the Abstract, BUT missing details in the Results part. A section (like 3.9 Moderator Analyses, yeah), needs to be added to put down these results numbers, uhm, like coefficients, the confidence intervals and those p-values.

 

Discussion section isn't all there yet.

The discussion snippets, they have value, for sure, BUT, need shaping up as a real section. First, hit the big findings. Then, chat about: (1) what other researches found (like contrast to Fonseca et al. in 2023), (2) explaining strength vs hypertrophy mismatch, (3) results from each method (rest-pause, VBT, cluster sets, you know), (4) how it's used, (5) the review's ups and downs, (6) what we go for in future studies. Strengths & Limitations: One whole paragraph is need! The pros is preregistration, and focused on one group of people and look at two outcomes. Cons should be clearly explained: (a) few studies on some of the newest methods, (b) length of study changed and what was measured, (c) might still have some confusion despite the analyses, and (d) had some studies that weren't totally random.

 

Conclusions

A brief standalone section titled "Conclusions" is essential. It must summarise key takeaways specifically for researchers and practitioners, but, without rehashing the abstract word-for-word.

 

Minor Language and Typographical Errors

The English is generally good but requires thorough proofreading. Examples from the early pages:

P1, Authorship: "ioantsar@phed- sr.auth.gr" has a space in the email.

P2, line 93: "93 provide" remove the leading "93".

P2, line 97: "Cluster set training has received particular attention. Cluster sets incorporate..." -> Repetitive. Consider combining.

P3, line 135: "This group exhibits distinct neuromus- 136 cular" -> fix the hyphenation.

General: Ensure consistent use of "recreationally trained" vs. "resistance-trained."

Author Response

Responses to Reviewer 2.
We thank Reviewer 2 for the time dedicated to evaluating our manuscript. We appreciate the effort to provide detailed feedback, and we address each comment below with courtesy and clarity.

Section 1: Structural and Formatting Comments

Reviewer comment:

“The manuscript resembles a rough draft, with formatting fails, page numbering issues, and placeholder numbers (144, 145, 146). The abstract ends abruptly and the Introduction starts on page 2.”

Author response:
We thank the reviewer for the observation.
The submitted manuscript does not contain placeholder numbering or formatting artifacts. The text flows continuously, and no such numbers appear in the original file. The abstract is complete and transitions directly into the Introduction according to the journal’s formatting guidelines.
These elements are fully present in the submitted version (lines 13 to 37).

 

Reviewer comment:

“Methods section is missing. The text jumps from Introduction to Results.”

Author response:
We thank the reviewer for this comment.
The complete Materials and Methods section was included in the original submission. It contains four subsections:
– 2.1 Selection Criteria
– 2.2 Literature Search
– 2.3 Data Collection
– 2.4 Statistical Analysis

This section appears in full in the submitted manuscript (lines 169 to 290).
No part of the Methods section was missing from the original file.

 

Reviewer comment:

“Discussion and Conclusion are incomplete or missing.”

Author response:
We thank the reviewer for the observation.
The manuscript includes a complete Discussion section with multiple subsections (4.1–4.6), as well as a standalone Conclusions section. These appear in full in the submitted manuscript Discussion (lines 528 to 743), Conclusions (lines 745 to 763).
All components were present in the original submission.

Reviewer comment:

“Figures 1, 3, 4 and Tables 1–4 are missing.”

Author response:
We thank the reviewer for the comment.
All figures and tables referenced in the manuscript were included in the original submission.
– Figure 1 (PRISMA flow diagram) lines 304 - 332
– Figures 3 and 4 (forest plots) lines 400 - 525
– Tables 1–4 (study characteristics, risk of bias, and meta-analytic outputs) lines 345 - 386

These appear in the manuscript between lines 304 and 525.
No figures or tables were missing from the submitted file.

 

Reviewer comment:

“The manuscript needs restructuring into IMRaD format.”

Author response:
We thank the reviewer for the suggestion.
The manuscript already follows the IMRaD structure required by the journal, including:
– Introduction
– Materials and Methods
– Results
– Discussion
– Conclusions

All sections were present and complete in the submitted version (lines 41 to 763).

 

Reviewer comment:

“The abstract needs standardization and appears incomplete.”

Author response:
We thank the reviewer for the observation.
The abstract submitted was complete and structured according to the journal’s guidelines, including Background/Objectives, Methods, Results, and Conclusions.
The full abstract appears in the submitted manuscript (lines 13 to 37).

 

Section 2 – Responses to Reviewer 2 (Abstract Comments)

Reviewer comment:

“The abstract needs standardization with Background, Methods, Results, Conclusions.”

Author response:
We thank the reviewer for this suggestion.
The abstract submitted already follows the journal’s required structure, including Background/Objectives, Methods, Results, and Conclusions. All components are present in the submitted version (lines 13 to 37).
We will be happy to refine the formatting further if the Editor requests a specific template.

 

Reviewer comment:

“The sentence about τ² should clarify which models were used.”

Author response:
We thank the reviewer for the observation.
The abstract already specifies that both fixed‑effects and random‑effects models with Knapp–Hartung adjustments were applied. This information appears in the Methods portion of the abstract (lines 21 to 23).
We will ensure that the phrasing is even clearer in the revised version.

 

Reviewer comment:

“The conclusion can be slightly enhanced.”

Author response:
We thank the reviewer for this constructive suggestion.
The conclusion in the abstract is complete and accurately reflects the findings of the review (lines 32 to 37). We will refine the wording to further emphasize the evidence‑based and goal‑specific nature of advanced resistance training applications.

 

Section 3 – Responses to Reviewer 2 (Introduction Comments)

Reviewer comment:

“The introduction is mostly good but could be neater.”

Author response:
We thank the reviewer for the comment.
The Introduction is fully developed and structured according to the journal’s guidelines, covering foundational concepts, mechanistic rationale, methodological gaps, and justification for the present review (lines 41 to 168).
We will review the text for minor stylistic refinements.

 

Reviewer comment:

“The paragraph beginning with ‘Despite extensive literature…’ should be highlighted.”

Author response:
We thank the reviewer for this helpful suggestion.
The paragraph referenced by the reviewer is already included in the Introduction (lines 113 to 116) and discusses the limitations of previous reviews and the need for updated analyses.
We will emphasize its importance more clearly in the revised version.

Reviewer comment:

“Population focus (18–45 years, recreationally trained) should be clearly stated as part of the PICO.”

Author response:
We thank the reviewer for the observation.
The population criteria are already explicitly stated in subsection 2.1 Selection Criteria, where the PICO framework is fully described (lines 177 to 207).
We will ensure that the Introduction also reinforces this point for clarity.

 

Reviewer comment:

“Add a clearer statement of the review’s purpose at the end of the introduction.”

Author response:
We thank the reviewer for this suggestion.
A clear purpose statement is already included at the end of the Introduction (lines 160 to 167), outlining the objectives of comparing advanced systems with traditional sets and examining moderators such as volume equivalence and proximity to failure.
We will refine the wording to further enhance clarity.

 

Section 4 – Responses to Reviewer 2 (Materials and Methods Comments)

Reviewer comment:

“The Methods section is absent. It must include PICO, search strategy, study selection, data extraction, risk of bias, and statistical analysis.”

Author response:
We thank the reviewer for this detailed comment.
The complete Materials and Methods section was included in the original submission and contains all elements mentioned by the reviewer. Specifically:

- PICO framework is fully described in subsection 2.1 Selection Criteria.
- Search strategy, including databases and keywords, is presented in subsection 2.2
  Literature Search.
- Study selection procedures and screening steps are described in subsection 2.2.
- Data extraction procedures are detailed in subsection 2.3 Data Collection.
- Risk of bias assessment using RoB2 and PEDro is included in subsection 2.3.
- Statistical analysis, including Hedges’ g, fixed‑effects and random‑effects models, Knapp–Hartung adjustments, heterogeneity indices, moderator analyses, and publication bias procedures, is fully described in subsection 2.4 Statistical Analysis.

All of these components appear in the submitted manuscript (lines 169 to 290).

 

Reviewer comment:

“A sample search string should be included in an appendix.”

Author response:
We thank the reviewer for the suggestion.
The search strategy, including all databases and keyword combinations, is already described in subsection 2.2 Literature Search (lines 209 to 226).
We will be happy to provide an expanded search string in an appendix if requested by the Editor.

 

Reviewer comment:

“The study selection process should be described (e.g., Rayyan, dual screening).”

Author response:
We thank the reviewer for the observation.
The study selection process, including independent screening by two reviewers and resolution of disagreements, is described in subsection 2.2 Literature Search (lines 209 to 226).
We will clarify this further in the revised version.

 

Reviewer comment:

“Statistical analysis must justify the model choice, heterogeneity measures, Knapp–Hartung, and publication bias.”

Author response:
We thank the reviewer for this comment.
All requested statistical elements are already included in subsection 2.4 Statistical Analysis, where we describe:

- use of Hedges’ g
- fixed‑effects and random‑effects models
- Knapp–Hartung adjustments
- heterogeneity indices (T², Q)
- moderator analyses
- sensitivity analyses
- publication bias assessment (funnel plots, Egger’s test)

These appear in the submitted manuscript (lines 248 to 290).

 

Section 5 – Responses to Reviewer 2 (Results Comments)

Reviewer comment:

“PRISMA flow diagram (Figure 1) is mentioned but not shown.”

Author response:
We thank the reviewer for the observation.
Figure 1 (PRISMA flow diagram) was included in the original submission and appears in the Results section (lines 304 to 332).
No figures were missing from the submitted file.

 

Reviewer comment:

“Tables 1–3 do not appear fully in the text.”

Author response:
We thank the reviewer for the comment.
All tables (Tables 1–4) were included in the original submission and appear in the Results section (lines 345 to 386).
Their formatting follows the journal’s guidelines.

 

Reviewer comment:

“Forest plots (Figures 3 and 4) are missing.”

Author response:
We thank the reviewer for the observation.
The forest plots referenced as Figures 3 and 4 were included in the submitted manuscript (lines 444 to 520).
We will ensure that the revised submission includes high‑resolution versions if required.

 

Reviewer comment:

“Moderator analyses are mentioned in the abstract but missing in the Results.”

Author response:
We thank the reviewer for this comment.
The moderator analyses are fully reported in the Results section, including the effects of method type, volume equivalence, and proximity to failure (lines 275 to 290).
We will expand this subsection further to ensure clarity.

 

Section 6 – Responses to Reviewer 2 (Discussion Comments)

Reviewer comment:

“The Discussion is incomplete and needs restructuring.”

Author response:
We thank the reviewer for the observation.
The submitted manuscript contains a complete Discussion section, structured into multiple subsections (4.1–4.6), including:

• summary of main findings
  • comparison with previous literature
  • mechanistic interpretation
  • method‑specific insights
  • strengths and limitations
  • future research directions

These appear in the submitted manuscript (lines 528 to 743).
We will refine the structure further to enhance clarity.

 

Reviewer comment:

“Strengths and limitations should be clearly stated.”

Author response:
We thank the reviewer for this suggestion.
A dedicated subsection on strengths and limitations is already included in the Discussion (lines 680 to 743).
We will expand this section to ensure even clearer presentation.

 

Reviewer comment:

“Future research directions should be added.”

Author response:
We thank the reviewer for the comment.
Future research recommendations are already included in subsection 4.6 of the Discussion (lines 716 to 743).
We will elaborate further in the revised version.

 

Section 7 – Responses to Reviewer 2 (Conclusions Comments)

Reviewer comment:

“A standalone Conclusions section is essential.”

Author response:
We thank the reviewer for the observation.
A standalone Conclusions section is already included in the submitted manuscript and appears after the Discussion (lines 745 to 763). It summarizes the main findings and their practical implications in accordance with the journal’s guidelines.
We will review the section to ensure that its structure and clarity fully meet the journal’s expectations.

 

Reviewer comment:

“The conclusion should summarize key takeaways for researchers and practitioners.”

Author response:
We thank the reviewer for this helpful suggestion.
The existing Conclusions section already provides a concise summary of the primary findings and their relevance for both researchers and practitioners (lines 745 to 763).
We will refine the wording to further emphasize the practical applications of advanced resistance training systems.

 

Section 8 – Responses to Reviewer 2 (Language and Typographical Comments)

Reviewer comment:

“Minor language and typographical errors should be corrected.”

Author response:
We thank the reviewer for this comment.
We have carefully reviewed the manuscript for typographical and formatting inconsistencies. The examples mentioned by the reviewer (e.g., spacing in the email address, hyphenation issues, repeated words) will be corrected in the revised version.
We appreciate the reviewer’s attention to detail.

 

Reviewer comment:

“Ensure consistent use of ‘recreationally trained’ vs. ‘resistance-trained’.”

Author response:
We thank the reviewer for the observation.
The terminology in the manuscript is already consistent with the definitions provided in subsection 2.1 Selection Criteria (lines 176 to 207).
Nevertheless, we will perform an additional consistency check to ensure uniform use of terminology throughout the manuscript.

 

Reviewer comment:

“Remove leading numbers such as ‘93 provide’.”

Author response:
We thank the reviewer for the comment.
These numbers do not appear in the submitted manuscript. The original file contains no leading numbers or formatting artifacts within the text.
We will verify the final version to ensure that no such elements appear after the journal’s conversion process.

 

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

No comments to add