Effect of an Intra-Sets Variable Resistance Potentiation Protocol on Throwing Speed in Elite Female Handball Players

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The study provides valuable insights into the PAPE protocol in handball using FEMD, and its methodology, despite certain limitations, is solid. The structure of the article is clear, the data is well presented, and the results and methods are thoroughly described.

However, I suggest that the Authors consider expanding on two aspects:

1. The article presents a well-known PAPE method, enhanced by the use of FEMD for controlling variable resistance. Therefore, it would be beneficial to emphasize more clearly how this approach differs from previous studies and what new possibilities it offers. A more detailed discussion of the unique aspects of FEMD in this context would strengthen the value of the paper.
2. The relatively small number of participants and the absence of a control group are significant limitations. Although they are mentioned in the discussion, it would be helpful to elaborate further on how they might have influenced the results and what steps could be taken to improve the quality of future research.

Author Response

Dear reviewer, thank you very much for your comments.

I'm sending suggested corrections.

Thank you very much.

Comment 1: The article presents a well-known PAPE method, enhanced by the use of FEMD to control variable resistance. Therefore, it would be beneficial to more clearly emphasize how this approach differs from previous studies and what new possibilities it offers. A more detailed discussion of the unique aspects of FEMD in this context would strengthen the article's value.

Response 1: The text is modified between lines 77 – 82. The references that have considered the study of validity and reliability with FEMD are added. "Functional electromechanical dynamometers (FEMD) have demonstrated high validity and reliability for assessing and controlling intensity and load in muscle strength exercises [30-32]. FEMDs allow for adjusting and controlling ranges of motion in analytical and/or functional exercises in single- or multi-joint actions, facilitating the control and manipulation of intensity in each repetition, set of exercises, intensity variations in a set [33] and load adjustment in PAPE protocols with IsVR."

 

Comment 2: The relatively small number of participants and the lack of a control group are significant limitations. Although mentioned in the discussion, it would be helpful to explain in more detail how they might have influenced the results and what steps could be taken to improve the quality of future research.

 

Response 2: Dear reviewer, we recognize the limitations of the study; however, the populations of elite or nationally selected athlete groups are always small. In our case, we took 100% of the players who had a level and participated in international competitions such as adult world championships, Pan American Games, and Olympic qualifiers. On lines 327-329, the text was modified to include the following: “It should be considered a limitation for future research projects that small, uncontrolled groups do not allow these results to be extrapolated to other, larger groups of athletes.” Additionally, on lines 113-115, in the methodology section, the description of the study population was specified. Also, in lines 327-329 in the limitations of the study and we recognize that the results cannot be extrapolated to other populations of elite athletes.

Reviewer 2 Report

Comments and Suggestions for Authors

Dear Editor,

I am grateful for the opportunity to evaluate the manuscript on women's handball. I will make observations by section to facilitate the editor and authors' understanding.

The authors should indicate the meaning of the effect size in the abstract. I suggest that the keywords do not repeat words in the title.

In the introduction, the text should be justified. The introduction is well-written. However, it is impossible to indicate how the manuscript advances about what is already known in the literature. What is the importance of this research, considering the state of the art on this topic? Furthermore, the hypotheses do not present theoretical support in the introduction. In this sense, why do the authors expect such results?

In the methods, considering the sample, the authors should better characterize the sample. Experience with the sport and titles won should be reported. The more information, the better, considering the convenience of sample selection.

The authors should better describe the protocols used. Which recommendation was followed for assessing muscle strength? How many sets were performed until failure? What is the rest period, among other information? The study must be reproducible.

In the results, the explanation in Table 1 was quite confusing (lines 198-205). The effect size is complementary to the findings through ANOVA. However, this is not how it is written. I ask that you rewrite it to make the text clearer.

At the end of the discussion, the authors must indicate the study's limitations, such as the small sample and the lack of a control group using traditional PAPE protocols with a smaller number of series.

Given the above, I suggest mandatory corrections, mainly justifying the conduct of a study in which no new information or gap in knowledge to be filled was indicated.

Best regards,

Reviewer

Author Response

Dear reviewer, thank you very much for your comments.

I'm sending suggested corrections.

Thank you very much.

 

Comment 1: Authors should indicate the meaning of the effect size in the abstract.

Response 1:The meaning of the effect size is explained on lines 31 and 32.

Comment 2: I suggest that keywords do not repeat words from the title.

Response 2: Added the keywords Resistance Training; Team Sports Games; Female Sport that are not repeated in the title

Comment 3: The text should be justified in the introduction.

Response 3: The text format is justified in the introduction.

Comment 4: The introduction is well-written. However, it is impossible to indicate how the manuscript advances what is already known in the literature. What is the importance of this research, considering the state of the art on this topic?

Response 4: Lines 77-82 of the introduction state that previous studies analyzing protocols for generating PAPE with IsVR manually modify the load and intensity, which hinders the reproducibility of the studies by not reporting how these variables are adjusted. In our study, as stated in the methodology section lines 132-134, the use of DEMF allows for automated control of load assignment and intensity changes, which in our opinion makes data collection more robust. In lines 92-94 of the introduction and lines 333-337 of the conclusion, we have added the importance of state-of-the-art research.

Comment 5: The hypotheses are not supported theoretically in the introduction. In this sense, why do the authors expect such results?

Response 5: The theoretical support for the components and variables of the hypothesis is added in lines 90-92 of the introduction.

Comment 6: In the methods section, considering the sample, the authors should better characterize the sample. Information should be provided on experience with the sport and qualifications earned. The more information, the better, considering the appropriateness of the sample selection.

Response 6: Added to lines 113-115 of the methodology section were all elite and selected international level players with participation in international competitions (Pan American Games qualifying for Olympic Games and adult world championships).

Comment 7: The authors should better describe the protocols used. What recommendation was followed to assess muscle strength? Maximum isometric strength (5 sec) (Jerez protocol) with 2 minutes between sets. How many sets were performed to failure? Maximum isometric strength was used. What is the rest period (2 min, among other information)? The study should be reproducible.

Response 7: Lines 142-145 of the methodology specify that the protocol for determining maximum strength considered a test of three 5-second isometric strength series separated by 4 to 5 minutes between sets. The peak value for each series was recorded, and the highest value achieved was used. The intensities of 30% and 60% of each repetition of the experimental protocol were adjusted.

Comment 8: In the results, the explanation in Table 1 was quite confusing (lines 198-205). The effect size is complementary to the findings from the ANOVA. However, it is not written that way. I request that you rewrite it to make the text clearer.

Response 8: in lines 215 – 219 the wording was modified "The Cohen's d effect size (ES) was used in a complementary manner to analyze the differences between the control group and the PAPE groups. Measurements that are considered null for the Baseline - PAPE 1 comparison and small Baseline - PAPE 2, Baseline - PAPE 3 and Baseline - PAPE 4 measurements were reported, as shown in Table 1."

Comment 9: At the end of the discussion, the authors should indicate the limitations of the study, such as the small sample size and the lack of a control group using traditional PAPE protocols with a smaller number of series.

Response 9: The limitation was written in lines 328 – 330 “It should be considered a limitation for future research projects that small, uncontrolled groups do not allow these results to be extrapolated to other, larger groups of athletes.”

Reviewer 3 Report

Comments and Suggestions for Authors

Thank you very much for the author's efforts in this study. The manuscript is well-structured, and the research content is rigorous. Below are a few minor suggestions to further improve the quality of the paper:

1. Formatting of Figure 2: Currently, Figure 2 spans two pages, which does not comply with the formatting requirements of the journal. Additionally, the error margin of PAPE2 is relatively large, whereas that of PAPE3 is much smaller. Could the authors clarify what factors contributed to this significant variation in error? Are there any methods that could be used to compensate for or eliminate these discrepancies to improve data reliability?

2. Error effects in Figure 3: Similarly, in Figure 3, the large error bars prevent PAPE1 from showing statistical significance compared to the Baseline. However, if the green error bars were effectively controlled, a significant difference might emerge. What are the authors’ considerations regarding this issue? Are there strategies to enhance data stability?

3. Visualization of the experimental process: If possible, it would be helpful to include additional images of the experimental process. This would provide readers with a clearer understanding of how the study was conducted and improve the reproducibility of the research.

4. Background on handball research: The study is well-designed, but I am curious about the rationale for choosing handball as the research focus. Is handball an Olympic sport? What is its most prestigious competition? As my research primarily focuses on Olympic events, if handball is an Olympic sport, I recommend emphasizing its significance in the Introduction. If it is not, providing information on its audience size and participation rates would help strengthen the study’s contextual background.

5. Comparison with real-world training methods: If feasible, I suggest comparing the proposed “intra-sets variable resistance potentiation protocol” with existing handball training methods to evaluate which approach is more effective. If experimental validation is not possible, a discussion of the potential advantages and limitations of both methods should be included in the Discussion section.

Author Response

Dear reviewer, thank you very much for your comments.

I'm sending suggested corrections.

Thank you very much.

Comment 1: Figure 2 spans two pages, which does not meet the journal's formatting requirements.

Response 1: It was modified to one page.

Comment 2: Furthermore, the margin of error for PAPE2 is relatively wide, while that for PAPE3 is much smaller. Could the authors clarify what factors contributed to this significant variation in error?

Response 2: The graph has been modified to address concerns among readers.

Comment 3: Are there methods to compensate for or eliminate these discrepancies and improve data reliability?

Response 3: There are methods for analyzing test-retest launch reliability, but this was not the focus of this study.

Comment 4: Effects of Error in Figure 3: Similarly, in Figure 3, the large error bars prevent PAPE1 from showing statistical significance compared to the baseline. However, if the green error bars were effectively controlled, a significant difference could emerge. What are the authors' considerations in this regard? Are there strategies to improve data stability?

Response 4: The graphs have been modified to facilitate reader understanding.

Comment 5: Visualization of the experimental process: If possible, it would be helpful to include additional images of the experimental process. This would provide readers with a clearer understanding of how the study was conducted and improve the reproducibility of the research.

Response 5: The research team believes that, with the modifications requested by other reviewers, the methodology is sufficiently explained to ensure the reproducibility of the study.

Comment 6: Background of the handball research: The study is well-designed, but I am interested in why handball was chosen as the research focus. Is handball an Olympic sport? What is its most prestigious competition? Since my research primarily focuses on Olympic events, if handball is an Olympic sport, I recommend highlighting its importance in the introduction. If not, providing information on its audience size and participation rates would help reinforce the context of the study.

Response 6: Lines 42–43 include the wording “which became an Olympic sport at the 1972 Munich Olympic Games.” Additionally, it was specified in line 113 – 115, the level of competition of the study subjects.

 

Comment 7: Comparison with actual training methods: If possible, I suggest comparing the proposed "within-set variable resistance potentiation protocol" with existing handball training methods to evaluate which approach is more effective. If experimental validation is not possible, an analysis of the potential advantages and limitations of both methods should be included in the Discussion section.

 

Response 7: On lines 271-274, a comparison is made with Pisz's study: "The study by Pisz et al. [24] implemented a PAPE protocol of bent-over barbell row, bench press, or push-up of 2 sets of 4 repetitions at 60% and 80% of 1RM, in professional female softball players, reporting significant improvements similar to those in this study, in medicine ball throwing."

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

Dear Editor, good afternoon! I understand that the authors have improved their writing. However, I believe they could provide better details about the sample since this would enhance the research and show the importance of the data obtained. Informing the athletes' placement in international championships would be a good option. Given what has been presented, I leave this suggestion to the authors since the manuscript does not need to be sent back for review.

Best regards,

Reviewer