The effect of plyometric training on physical performance in youth soccer players: A randomized controlled trial with maturation status as a covariate

Roman Holík; Jakub Krejčí; Mark De Ste Croix; Michal Lehnert

doi:10.1371/journal.pone.0349011

Peer Review History

Original SubmissionMarch 6, 2026
8 Apr 2026 Decision Letter - Stefano Amatori, Editor PONE-D-26-10103The effect of plyometric training on physical performance in youth soccer players: A randomized controlled trial with maturation status as a covariatePLOS One Dear Dr. Krejčí, Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process. We received the comments from the two reviewers. Both suggested the paper to be accepted, but some of their comments need to be addressed before fully considering the paper for publication. Please find their comments below. Please submit your revised manuscript by May 23 2026 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. 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Thank you for stating in your Funding Statement: This study was supported by the Internal Grant Agency of Palacký University Olomouc (URL: www.upol.cz), grant number IGA_FTK_2024_013, entitled “Effects of a plyometric training program on young athletes of different biological ages”. Please provide an amended statement that declares all the funding or sources of support (whether external or internal to your organization) received during this study, as detailed online in our guide for authors at http://journals.plos.org/plosone/s/submit-now. Please also include the statement “There was no additional external funding received for this study.” in your updated Funding Statement. Please include your amended Funding Statement within your cover letter. We will change the online submission form on your behalf. 3. Thank you for stating the following financial disclosure: This study was supported by the Internal Grant Agency of Palacký University Olomouc (URL: www.upol.cz), grant number IGA_FTK_2024_013, entitled “Effects of a plyometric training program on young athletes of different biological ages”. Please state what role the funders took in the study. If the funders had no role, please state: "The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript." If this statement is not correct you must amend it as needed. Please include this amended Role of Funder statement in your cover letter; we will change the online submission form on your behalf. 4. Thank you for stating the following in the Competing Interests section: I have read the journal's policy and the authors of this manuscript have the following competing interests: Roman Holík is a coach at the soccer club (FK Stipa, Zlin, Czech Republic) where the research was conducted. The other authors have declared that no competing interests exist.We note that one or more of the authors are employed by a commercial company. a. Please provide an amended Funding Statement declaring this commercial affiliation, as well as a statement regarding the Role of Funders in your study. 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Please confirm that this does not alter your adherence to all PLOS ONE policies on sharing data and materials, by including the following statement: "This does not alter our adherence to PLOS ONE policies on sharing data and materials.” (as detailed online in our guide for authors http://journals.plos.org/plosone/s/competing-interests). If there are restrictions on sharing of data and/or materials, please state these. Please note that we cannot proceed with consideration of your article until this information has been declared. Please include your updated Competing Interests statement in your cover letter; we will change the online submission form on your behalf. 6. If the reviewer comments include a recommendation to cite specific previously published works, please review and evaluate these publications to determine whether they are relevant and should be cited. There is no requirement to cite these works unless the editor has indicated otherwise. 7. Please review your reference list to ensure that it is complete and correct. If you have cited papers that have been retracted, please include the rationale for doing so in the manuscript text, or remove these references and replace them with relevant current references. Any changes to the reference list should be mentioned in the rebuttal letter that accompanies your revised manuscript. If you need to cite a retracted article, indicate the article’s retracted status in the References list and also include a citation and full reference for the retraction notice. [Note: HTML markup is below. Please do not edit.] Reviewers' comments: Reviewer's Responses to Questions Comments to the Author 1. Is the manuscript technically sound, and do the data support the conclusions? The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented. Reviewer #1: Yes Reviewer #2: Yes ******** 2. Has the statistical analysis been performed appropriately and rigorously? Reviewer #1: Yes Reviewer #2: Yes ****** 3. Have the authors made all data underlying the findings in their manuscript fully available? The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified. Reviewer #1: Yes Reviewer #2: Yes ****** 4. Is the manuscript presented in an intelligible fashion and written in standard English? PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here. Reviewer #1: Yes Reviewer #2: Yes ****** 5. Review Comments to the Author Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters) Reviewer #1:** Dear authors, Thank you for your submission. I think it was well written. I have a small number of recommendations. Method Please include a reference for all test protocols - e.g. a citation for CMJ line 188 and do the same for all tests. Please add equations and calculations for: - Boys PHV - Malian et al. 2020 - CMJ height - the Optojump uses the flight-time method outlined by Glatthorn 2011 - RSI mm/ms outlined by Flanagan and Comyns 2008 - Leg stiffness - equation can be found in the leg stiffness in female Soccer players by De Ste Croix and Lehrert - Relative leg stiffness - McMahon and Cheng 1990 I think doing this would add to the rigour of the manuscript. You should think about adding an abbreviation section - refer to Lloyd et al. 2009. Statistical analysis How was the sample size determined? GPower? Detail the exact procedure. Please add this to Statical analysis section. Discussion I think you should include some the data from the r was ultra to back up discussion points. Also, i think you should cite some of the adaptations following PT - refer to Markovic and Mikulic 2010. Limitations A further limitation was that the study didn't include a mid-PHV. Can you detail what this Might mean - would the results be similar in the mid-PHV group? If yes/no, why? Read the meta-analysis by Ramirez-Campillo and Sortwell 2023. I hope this helps. Reviewer #2:* The study aimed to investigate whether the performance benefits of CMJ training are influenced by biological maturation status. This is a relevant and timely research question, particularly considering the importance of biological maturation in youth athletic development and training responsiveness. However, although maturation status was included as a covariate, designing and implementing the training program according to the participants’ maturation stage might have allowed for a more precise evaluation of training adaptations and potentially revealed differential responses across maturation groups. Such an approach may also strengthen the practical implications for coaches and practitioners working with youth soccer players. Overall, the manuscript is clearly written and methodologically sound. No further major comments or additional suggestions. ******** 6. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files. If you choose “no”, your identity will remain anonymous but your review may still be made public. Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy. Reviewer #1: Yes: Lee David McGarrigal Reviewer #2: No ******** [NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.] To ensure your figures meet our technical requirements, please review our figure guidelines: https://journals.plos.org/plosone/s/figures You may also use PLOS’s free figure tool, NAAS, to help you prepare publication quality figures: https://journals.plos.org/plosone/s/figures#loc-tools-for-figure-preparation. NAAS will assess whether your figures meet our technical requirements by comparing each figure against our figure specifications. https://doi.org/10.1371/journal.pone.0349011.r001
Revision 1
21 Apr 2026 Author Response Reviewer #1 We would like to thank the reviewer for the time he spent reviewing the manuscript and for the constructive feedback. It has helped us improve the quality and clarity of our manuscript. We carefully revised the manuscript according to their comments and have provide a point-by-point response to each comment. Comment: Dear authors, Thank you for your submission. I think it was well written. I have a small number of recommendations. Method. Please include a reference for all test protocols - e.g. a citation for CMJ line 188 and do the same for all tests. Please add equations and calculations for: - Boys PHV - Malian et al. 2020 - CMJ height - the Optojump uses the flight-time method outlined by Glatthorn 2011 - RSI mm/ms outlined by Flanagan and Comyns 2008 - Leg stiffness - equation can be found in the leg stiffness in female Soccer players by De Ste Croix and Lehnert - Relative leg stiffness - McMahon and Cheng 1990 I think doing this would add to the rigour of the manuscript. Response: We have added a formula for calculating the maturity offset to the manuscript. We agree that the description of the three tests involving some form of jump (CMJ, RSI, and leg stiffness) was somewhat vague and could have led to confusion. Therefore, we have added protocol specific references for each test. Additionally, we have included the formula needed to calculate RSI. In the case of CMJ and leg stiffness, we have omitted the formulas because describing the procedure requires a list of several formulas. Therefore, we prefer to refer readers to the literature. To review the changes in the methods section, please see the manuscript with tracked changes. We hope these changes have improved the rigor of the manuscript. Comment: You should think about adding an abbreviation section - refer to Lloyd et al. 2009. Response: Thank you for this suggestion. According to the PLOS Submission Guidelines, abbreviations should be defined upon first appearance in the text. A list of abbreviations is not required. Therefore, we have not included a separate section with abbreviations. However, we have carefully reviewed the manuscript to ensure that all abbreviations are defined upon their first appearance and are used consistently throughout the manuscript. Comment: Statistical analysis. How was the sample size determined? GPower? Detail the exact procedure. Please add this to Statical analysis section. Response: Thank you for this comment. The following text has been added to the manuscript at the end of the section on statistical analysis: “For logistical reasons, the sample size was limited by the availability of participants from a single soccer club. Therefore, no a priori power analysis was conducted. Instead, a posteriori sensitivity analysis was performed using the GPower software version 3.1.9.7 (Heinrich-Heine-Universität, Düsseldorf, Germany). A two-tailed paired t-test was considered for the calculation, as the Fisher’s least significant difference test used in this study for pairwise comparisons is a special type of t-test. The following values were used for the calculation: significance level α = 0.05, power 1−β = 0.80, sample size n = 10 or 7. The required effect size was calculated to be d = 1.0 or 1.3, respectively.” Comment: Discussion. I think you should include some the data from the r was ultra to back up discussion points. Response: Thank you for this comment. Unfortunately, we were unable to determine the exact meaning of the term “r” in this comment. One possible interpretation is that this refers to the statistical software R, which, however, was not used in the manuscript. Another possible interpretation is that this refers to correlation coefficients between selected performance variables. However, correlation analysis was not part of the original study design, and in our opinion, its inclusion would not be consistent with the aim of the study. Furthermore, it would considerably expand the scope of an already extensive manuscript. Comment: Also, I think you should cite some of the adaptations following PT - refer to Markovic and Mikulic 2010. Response: Thank you for this suggestion. We understand this comment as a recommendation to better support in the discussion the mechanisms underlying the observed changes in performance following plyometric training. Therefore, we have added the review by Markovic and Mikulic (2010) to the relevant points in the discussion, which supports statements related to neuromuscular and musculoskeletal adaptations following plyometric training. Comment: Limitations. A further limitation was that the study didn't include a mid-PHV. Can you detail what this might mean - would the results be similar in the mid-PHV group? If yes/no, why? Read the meta-analysis by Ramirez-Campillo and Sortwell 2023. Response: Thank you for this important comment. We agree that the absence of a circa-PHV group is a limitation of the present study. Unfortunately, we did not have a sufficient number of participants in this maturity category to create a separate group for a valid statistical analysis. Therefore, we are unable to determine whether the response of circa-PHV players would be more similar to the pre- or post-PHV group. We have clarified this point in the limitations section as follows: “Another limitation of the present study is the absence of a circa-PHV group, which limits the ability to assess how players around peak height velocity might have responded compared to pre-PHV and post-PHV groups.” Reviewer #2 The study aimed to investigate whether the performance benefits of CMJ training are influenced by biological maturation status. This is a relevant and timely research question, particularly considering the importance of biological maturation in youth athletic development and training responsiveness. However, although maturation status was included as a covariate, designing and implementing the training program according to the participants’ maturation stage might have allowed for a more precise evaluation of training adaptations and potentially revealed differential responses across maturation groups. Such an approach may also strengthen the practical implications for coaches and practitioners working with youth soccer players. Overall, the manuscript is clearly written and methodologically sound. No further major comments or additional suggestions. Response: We would like to thank the reviewer for the time he/she spent reviewing the manuscript and for their positive evaluation. Although the reviewer had no comments to incorporate, the manuscript was revised according to the comments of Reviewer 1, which we hope has further improved the quality and clarity of our manuscript. https://doi.org/10.1371/journal.pone.0349011.r002
23 Apr 2026 Decision Letter - Stefano Amatori, Editor The effect of plyometric training on physical performance in youth soccer players: A randomized controlled trial with maturation status as a covariate PONE-D-26-10103R1 Dear Dr. Krejčí, We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements. Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication. An invoice will be generated when your article is formally accepted. Please note, if your institution has a publishing partnership with PLOS and your article meets the relevant criteria, all or part of your publication costs will be covered. Please make sure your user information is up-to-date by logging into Editorial Manager at Editorial Manager® and clicking the ‘Update My Information' link at the top of the page. For questions related to billing, please contact billing support. If your institution or institutions have a press office, please notify them about your upcoming paper to help maximize its impact. If they’ll be preparing press materials, please inform our press team as soon as possible -- no later than 48 hours after receiving the formal acceptance. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact onepress@plos.org. Kind regards, Stefano Amatori, Ph.D. Academic Editor PLOS One Additional Editor Comments (optional): Reviewers' comments: https://doi.org/10.1371/journal.pone.0349011.r003
Formally Accepted
Acceptance Letter - Stefano Amatori, Editor PONE-D-26-10103R1 PLOS One Dear Dr. Krejčí, I'm pleased to inform you that your manuscript has been deemed suitable for publication in PLOS One. Congratulations! Your manuscript is now being handed over to our production team. At this stage, our production department will prepare your paper for publication. This includes ensuring the following: * All references, tables, and figures are properly cited * All relevant supporting information is included in the manuscript submission, * There are no issues that prevent the paper from being properly typeset You will receive further instructions from the production team, including instructions on how to review your proof when it is ready. Please keep in mind that we are working through a large volume of accepted articles, so please give us a few days to review your paper and let you know the next and final steps. Lastly, if your institution or institutions have a press office, please let them know about your upcoming paper now to help maximize its impact. If they'll be preparing press materials, please inform our press team within the next 48 hours. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact onepress@plos.org. You will receive an invoice from PLOS for your publication fee after your manuscript has reached the completed accept phase. If you receive an email requesting payment before acceptance or for any other service, this may be a phishing scheme. Learn how to identify phishing emails and protect your accounts at https://explore.plos.org/phishing. If we can help with anything else, please email us at customercare@plos.org. Thank you for submitting your work to PLOS ONE and supporting open access. Kind regards, PLOS ONE Editorial Office Staff on behalf of Prof. Stefano Amatori Academic Editor PLOS One https://doi.org/10.1371/journal.pone.0349011.r004

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