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Thank you for addressing my requested revisions, the research has been strengthened even further and presents useful outcomes for end-users. Congratulations on this work!
[# PeerJ Staff Note - this decision was reviewed and approved by Mike Climstein, a PeerJ Section Editor covering this Section #]
**PeerJ Staff Note:** Although the Academic and Section Editors are happy to accept your article as being scientifically sound, a final check of the manuscript shows that it would benefit from further English editing. Therefore, please identify necessary edits and address these while in proof stage.
Dear authors,
Thank you kindly for taking the time to address the extensive list of suggestions I previously made - the manuscript has been greatly strengthened as a result of these changes. In reading through this version, I do however, have some final, minor suggestions to address before recommending acceptance. If possible, please consider these final changes where you agree:
#1 Line 20: Change to "Independent samples t-tests and one-way ANOVAs...".
#2 Line 22: Change to "...investigate intragroup relationships between morphological and physical fitness variables". Otherwise, please adjust the end of this sentence to clearly mention what the correlations were exploring.
#3 Line 23: Be sure to use past tense for results, so change "is" to "was" here and "exist" to "existed" on the next line.
#4 Line 25: Please indicate "in favour of older athletes" or something similar on this line to indicate better fitness was observed in the U18 group.
#5 Lines 29-30: Try to indicate the test outcome here, so "T-test time", "standing long jump distance", "30-m sprint time", "30-s bodyweight squat performance", and "400-m running time".
#6 Line 53: Add a colon (:) after "that" here given you separate each point with a semi-colon further in the sentence.
#7 Line 67: Change to "rugby league" rather than "rugby" on its own here given it is the specific sport investigated in the study you cite.
#8 Line 73: "mature" should be "maturity" here before "status".
#9 Line 90: Remove "to" at the start of aim (ii) and aim (iii).
#10 Line 116: Change "9 AM" to "09:00" as 24-hour time here.
#11 Line 117: Here you use the term "subjects", so try to be consistent with terminology throughout, as you use "participants" elsewhere, and then sometimes "athletes" to.
#12 Line 119: "agility" should be "change-of-direction speed" instead here.
#13 Lines 121-122: Change "meter" to "m" each time here (same applies on line 177).
#14 Line 126: Typically terms are not abbreviated in headings like this.
#15 Line 130: Please change to "age at peak height velocity" rather than "of" and should this term not be capitalized?
#16 Line 145: Change to "...using a validated bioelectrical impedance analyzer (InBody 770...)", including the validity citation after "validated" and removing the last sentence.
#17 Line 148: Please adjust "agility" to "change-of-direction speed" throughout as you do not explicitly measure agility given the tests adopted do not contain a cognitive, decision-making process in response to a stimulus. When such a stimulus is not included, the test measures change-of-direction speed. It ay also be called "pre-planned agility" but should not be labelled as "agility" on its own like this according to definitions established in the literature. Please consider this throughout.
#18 Line 171: Change "of 30m" to "across 30 m" with a space between number and unit.
#19 Line 173: Change to "30-m" sprint with a hyphen here.
#20: Line 178: "stats" should be "starts" here, and add "an" before "athletic" here.
#21 Line 208: Presentation of "one minute" should be "1 minute" in line with how you present elsewhere? On that front, the use of numerals or words to describe numbers is somewhat inconsistent, so please check and ensure you follow a consistent method.
#22 Line 210: Change to "400-m and 1500-m runs" with hyphens between numbers and units. Change to this usage on liens 211,212, and 218 given they are different there too. Change to "400-m" on line 215 as "meters" is written in full here.
#23 Line 220-221: Change to "Athletes were grouped based on..." as it is not a complete sentence as currently written.
#24 Line 223: No need to hyphenate "age-groups" here. Also, perhaps say normal distribution was "confirmed" rather than "performed" to show that data were normal.
#25 Line 226: Change to "i.e.," inside the brackets here.
#26 Line 227: Perhaps specify as "one-way" ANOVA here.
#27 Line 231: Try to give a range for small, medium, and large effects here rather than single values (e.g., small = 0.20-0.49, medium = 0.50-0.79, and large => 0.80) - also, start a new sentence rather than semi-colon for Partial eta squared.
#28 Lines 243-248: This sentence is not as clear as it could be. For one, just write "d" each time instead of "Cohen's d" given it is the effective statistic symbol. Also, to show the direction, perhaps change the start of the sentence on line 243 to "U18 athletes displayed significantly greater height...". For the second sentence on lines 245-248, change to "U18 players also exhibited significantly superior T-test (p =0.009, d =1.31), standing long jump (p =0.005, d =1.40), 30-m sprint (p=0.002, d =1.50), pull-up (p =0.045, d =0.85), and 400-m run (p =0.015, d =1.12) performances.
#29 Line 249: Add "performance, favoring the elite group" after "sit-up" and before the brackets here.
#30 Line 250: Elaborate here by stating "Figure 2 shows the effect sizes for comparisons between elite and sub-elite groups" instead of the sentence given.
#31 Line 252: Change to "In terms of maturity status, Figure 3 shows the differences between maturity groups, with statistical outcomes shown in Table 2" instead of the two sentences presented. There is no need for the sentence "Multiplate comparisons were also conducted within the three groups", so please remove it.
#32 Lines 253-264: Perhaps change to be more brief and indicate directions of differences as: "There were significant differences in age (p<0.001, d =-3.076), maturity offset (p<0.001, d =-3.555), height (p=0.001, d =-2.023), body mass (p<0.001, d =-2.567), BMI (p<0.001, d =-2.473), sitting height (p<0.001, d =-2.696), T-test time (p=0.011, d =1.375), standing long jump distance (p=0.01, d =-1.407), and 30-s bodyweight squat repetitions (p=0.014, d =-1.324) between pre-PHV and circum-PHV, favoring the more mature group. Significant differences were also present between pre-PHV and post-PHV in age (p<0.001, d =-4.658), maturity offset (p<0.001, d =-5.834), height (p<0.001, d =-3.267), body mass (p<0.001, d =-4.320), BMI (p<0.001, d =-3.975), sitting height (p<0.001, d =-4.448), leg length (p=0.01,262 d =-1.639), and 30-m sprint time (p=0.003, d =1.955), favoring the more mature group. However, no significant differences were observed between circum-PHV and post-PHV groups across measures." Also, look to present Cohen's d values to two decimal places throughout instead of three decimal places.
#33 Line 266: Change to "...revealed significant correlations among..." rather than "...revealed a significantly correlation among...".
#34 Line 269: Add "measures" after "performance" at the end of this sentence. Or use the term "variables" instead of "measures" actually - can you check this throughout?
#35 Line 278: Change "analyze" to "analyzed". Also, remove the sentence "Athletes are tested using basic morphometric measures and selected physical fitness indicators".
#36 Line 284: Remove "most" here given all fitness measures were not different between these groups.
#37 Lines 285-288: Change to "Furthermore, varying correlations were found between anthropometric variables, physical performance, age, and maturity. Correlations between chronological age and maturity status with various physical performance variables were relatively consistent, which may be due to interactions between talent selection, specific training, and maturity status".
#38 Lines 351, 353, and 354: Try to add "finding", "trend", "notion", or something relevant after "This" when starting each sentence here. Just stating "This" on its own adds confusion as the reader may not be certain what is being referred to each time.
#39 Discussion: This is not a necessity, but there does not appear to be any real discussion of the correlation analyses results in this section. Is any warranted or can any be incorporated into existing content as further discussion where relevant?
#40 Line 407: No need to hyphenate "physical-fitness" here.
#41 Line 411: Change "weight" to "body mass" - check this throughout the discussion as it was used there too. There is not need to hyphenate "body-fat" here.
There are some further changes needed to strengthen some aspects of the manuscript and improve the writing in places. Please take time and care in addressing these revisions - and please ensure the English language throughout is improved beyond the comments provided (even recruit an additional person to help with this aspect if needed). I have tried to be specific in my suggestions, so please consider each of them presented below:
ABSTRACT
#1 Abstract, line 12: Change to past tense - "aimed" not "aims".
#2 Abstract, line 13: Add "youth breaking athletes" or something similar at the end of the aim statement to indicate the population.
#3 Abstract, line 15: You use the term "breaking athletes" in the title but then use "breakdancers" here. Please be consistent in your use of terminology when referring to this population throughout.
#4 Abstract, line 15: "were" should be "was".
#5 Abstract, line 16: this sentence is not accurate based on the methods you present further down. Please reframe this sentence to be more in line with the processes followed to determine maturity status.
#6 Abstract, line 17: remove "were recorded".
#7 Abstract, line 18: if possible identify the different "groups" for each factor you are exploring (age, maturation, and level) before the results so they can be subsequently interpreted.
#8 Abstract, results: when indicating the differences, please state which groups were higher or lower than others rather than simply stating they were different. Also, no need to present F statistics or eta-squared values, probably just stick to p-values given this is what the interpretations are based on. On this note, please present "p" the same way throughout as it is capitalized and italicised in places and not in others.
#9 Abstract, results: there is no mention of correlation results at all? In fact, it is difficult to understand what the correlation analyses pertain to based on the abstract along, so can you improve clarity on this part?
INTRODUCTION
#10 Introduction, line 39: no need to capitalize "Breaking" - check throughout.
#11 Introduction, line 41: no need to capitalize "Time" here.
#12 Introduction, line 43: replace "energy" with "metabolism".
#13 Introduction, line 46: no need to capitalize "National Breaking Team".
#14 Introduction, line 54: this sentence is awkwardly worded. Please rephrase it for clarity.
#15 Introduction, lines 61-62: please adjust this sentence to something like "Many studies have explored this aspect in other sports, such as rugby league and basketball; however, research is lacking for breaking in this area."
#16 Introduction, line 63: please rephrase to something like "The high proportion of adolescent breakers among the top athletes in the sport indicates maturity status may play a crucial role in competitive success".
#17 Introduction, line 68: "mature state" should be "maturity status".
#18 Introduction, line 69: change "physical performance" to "physical attributes" or similar given you use the term performance again in a few words.
#19 Introduction, line 72: these terms each do not need to be capitalized.
#20 Introduction, line 80: no need for a hyphen here.
#21 Introduction, line 81: perhaps change "during puberty" to "throughout maturation" or similar?
#22 Introduction, aims: the aims should be adjusted to two key statements, the first being to profile/describe the anthropometric and physical fitness characteristics and the second to compare them according to chronological age, maturation status, and performance level. In addition, please take care to be consistent in the terminology you use. For instance, please use "anthropometric and physical fitness characteristics" throughout to describe these aspects as it varies considerably. Also, please be consistent in naming the different "factors" you are exploring in this study.
#23 Introduction: If you had pre-developed hypotheses, these should be included after your aims.
METHODS
#24 Methods, line 95: What "physical training" was completed? Can you give some idea on this, such as cardiorespiratory endurance, muscular strength, power, etc.?
#25 Methods, line 104: Remove "A" to start this sentence.
#26 Methods, Figure 1: Perhaps consider making the font better as when this image is presented in the journal to scale the writing will be hard to read. There is ample space in this figure, so enlarging the font should not change other aspects greatly.
#27 Methods, line 122 and 124: "peak height velocity" does not need to be capitalized.
#28 Methods, line 130: change "and" to "or".
#29 Methods, throughout: please change all mention of "weight" to "mass". Body mass refers to the measurement in kg, where "weight" refers to a force in N - so I believe you are referring to "body mass" each time.
#30 Methods, line 133: do you mean "stadiometer" rather than "height tester"? Please adjust with better terminology where this is mentioned each time.
#31 Methods, line 135: here you say "subject" but elsewhere you say "athletes" or other terms. Again, please be consistent with the terminology you adopt to describe your sample throughout - I would probably recommend "athlete" over others.
#32 Methods, line 140: There is not need to mention "DEXA", and I believe you mean "valid" rather than "reliable" here? Please adjust this sentence accordingly.
#33 Methods, throughout: The term "agility" actually refers to a change in direction performance involving a stimulus with cognitive decision-making. When there is no such stimulus in this type of testing, it is referred to as "change-of-direction speed". So I would recommend you adjust your terminology throughout to avoid use of "agility" for this reason - see here for example, https://journals.sagepub.com/doi/10.1260/1747-9541.10.1.159.
#34 Methods, line 146: You use the abbreviation "HOT" but have not defined this anywhere.
#35 Methods, line 148: You cite the same references twice in the one sentence. Perhaps remove them from the end of the sentence given you put them next to the reliability statistics already.
#36 Methods, line 149: "Photoelectric" does not need to be capitalized.
#37 Methods, line 156: change "low limbs" to "lower-limb". Check this throughout as "lower-limb" should be hyphenated each time it is mentioned.
#38 Methods, standing long jump: please specify that athletes remained planted until distance was marked or measured, and indicate whether the distance was taken from the front or back of the foot with the tape measure.
#39 Methods, throughout: sometimes you use the correct abbreviations for units but other times you write the unit in full - please just sick with writing the abbreviation each time given they are well established (for example, m vs. meters). Please check this aspect for each unit throughout.
#40 Methods, line 168: if sprints were timed electronically, how could a false start be achieved? Is this an error as there shouldn't be a start signal? Also, how far behind the initial timing gate were athletes standing when the commenced the sprint test? This should be mentioned.
#41 Methods, line 172: add "The" before "squat test".
#42 Methods, line 174: change the full-stop to a comma here.
#43 Methods, line 178: change the colon to a full-stop here.
#44 Methods, line 197: change "are" to 'were" and "touch" to "touched" - methods should be written in past tense.
#45 Methods, line 203: these are not "capacity" tests, so please adjust this sentence accordingly to reflect what these tests measure.
#46 Methods, line 208: if an electronic timing system was used, why was a start signal involved? These systems typically start recording performance time upon volition of the participants automatically without any tester input to initiate the start. Clearer description on the timing of the linear sprint, 400-m run, and 1500-m run are needed in your methods.
#47 Methods, line 212: the different groups within each factor must be clearly described as you have not done this for chronological age yet?
#48 Methods, line 213: if some variables are not normal, why are means and SDs presented for them? Shouldn't they be presented as median and IQR - also, please clearly indicate which variables were not normal.
#49 Methods, lines 215-216: please join these sentences and adjust for clarity so they read effectively in terms of identifying differences.
#50 Methods, line 222: again, for data that were not normal, what effect sizes were calculated? These mentioned effect size statistics are applicable to normal data?
RESULTS
#51 Results, line 230: no need to capitalize these terms.
#52 Results, Table 1: please improve presentation of variables down the side (e.g., units for BMI presented poorly, abbreviations defined, hyphens between number and "s" and "m" in selected variables). Also, please include "n=" in brackets for all categories, not just the first two.
#53 Results, lines 230-240: When summarizing differences in text, please indicate which group was higher or lower rather than just stating differences were found. Also, given the effect sizes are presented in Figure 2, there is no need to duplicate these findings and present them in text too - please remove them in this sense. Also, to ensure this part can be really concise and you can remove p-values, consider including the p-value next to the effect size in the figure - it will greatly cut back on text and make this section much more readable.
#54 Results, lines 241-259: This is a lot of text that is very difficult to interpret. To improve the readability, consider incorporating another table that contains all the statistical outcomes concerning the comparisons between maturity groups clearly. In this way, you could remove much of the detail here and just summarize where the main differences were without statistical data. The results section needs considerable work to improve clarity.
#55 Results, lines 260-263: Figure 4 does not need to be a full correlation matrix. Given you are only interested in correlations between each of the main predictors (chronological age, maturity, and APHV) with each anthropometric/fitness variable, you should present them as a table where you have each of the main predictors across the top and each of the other variables down the side. This way, you could also incorporate confidence intervals, which would be useful. In fact, if some data were not normal, shouldn't Spearman rank correlations between presented for them? Please present these data more effectively. Also, the written interpretation is vague here, so please be more precise in summarizing the key significant correlations that were found rather than just stating "different" correlations were found among variables. If this is too problematic, perhaps consider removing correlation analyses altogether since they are not given much attention elsewhere.
DISCUSSION
#56 Discussion, lines 272-273: "examine" should be "examined" and "analyze" should be "analyzed" - check for past tense throughout in similar instances. Also, you didn't examine "influence" but you examined whether they differed according to chronological age, maturation status, and level - so please adjust this sentence to reflect these points.
#57 Discussion, lines 274-276: This sentence is not needed as justification has been included in the methods, please remove it.
#58 Discussion, line 276: remove the term "research" before "results".
#59 Discussion, line 288: change "researc" to "study" here.
#60 Discussion, line 260: exploring relationships between the anthropometric and fitness variables was not part of your aim, so it seems odd to introduce discussion along these lines here?
#61 Discussion, lines 293-295: The same sentence is repeated twice here in a row - please pay careful attention to your contents and writing, which has to be greatly improved if this work is to be considered for publication.
#62 Discussion, line 298: what does "about 7%" refer to? Please be clearer.
#63 Discussion, lines 306-312: again, it is not clear why you anthropometric characteristics are being correlated with fitness characteristics, especially given you speculate these fitness characteristics might be important for performance, but do not support this notion with your other findings.
#64 Discussion, line 313: what does "This" refer to opening this new paragraph? Please be more precise.
#65 Discussion, line 317: if rounds are "short" and intense, this would imply reliance on anaerobic properties, so why do you mention "cardiorespiratory function" here? The contents and reasoning do not match this terminology accurately here, so please adjust.
#66 Discussion, line 339: can you give some recommendations of potential tests? What about isometric type tests given the requirement to "hold" positions for example? What about whole-body/upper-body endurance tests as opposed to just "running" tests? Some further direction on what could be examined may help your point here - however, this is up to you where you want to add further.
#67 Discussion, line 342: "circa" is not consistent with your earlier terminology here.
#68 Discussion, lines 357-358: this sentence is not clear - what is meant by agility and strength are important for future development and how is this supported in your data? More direct explanations supported by the results are needed here.
#69 Discussion, line 368: here you use the term "teen" and elsewhere you use the term "adolescent" and "teenager". Please be consistent in your language, and I would suggest using "adolescent" or derivatives of this term in all instances throughout.
#70 Discussion, line 370: "indexes" should be "indices".
#71 Discussion, line 371: could it be that the levels were not different enough in physical performance for a difference to be detected or that other elements like skill and creativity become more important in separating levels once a requisite level of physical development is achieved? You allude to these points earlier, but here you only conclude that better fitness testing needs to be developed. Consider adjusting this conclusion for a more rounded point.
CONCLUSION
#72 You have a "summary" paragraph at the end of the discussion, so please consider removing that paragraph and working it together with the conclusion. Also, be sure the statements in your conclusion are precise and backed by the evidence you present, rather than any speculation being presented.
**Language Note:** The Academic Editor has identified that the English language must be improved. PeerJ can provide language editing services - please contact us at [email protected] for pricing (be sure to provide your manuscript number and title). Alternatively, you should make your own arrangements to improve the language quality and provide details in your response letter. – PeerJ Staff
**PeerJ Staff Note:** Please ensure that all review, editorial, and staff comments are addressed in a response letter and that any edits or clarifications mentioned in the letter are also inserted into the revised manuscript where appropriate.
**Language Note:** When you prepare your next revision, please either (i) have a colleague who is proficient in English and familiar with the subject matter review your manuscript, or (ii) contact a professional editing service to review your manuscript. PeerJ can provide language editing services - you can contact us at [email protected] for pricing (be sure to provide your manuscript number and title). – PeerJ Staff
The manuscript is written in clear, professional English and generally follows PeerJ formatting guidelines. The introduction presents appropriate background and references. Figures and tables are relevant and well-constructed. However:
Reference [36] is incomplete and must be corrected or replaced.
Reference [33] is redundant with [30] and should be removed.
Reference [1], being a website, requires an access date for proper formatting.
These minor issues aside, the manuscript is readable and appropriately structured.
Major Comment 1 – Missing Breakdown of Training Components
Although the authors mention a total weekly training volume (36 hours), they do not specify how this time is distributed across various types of breaking training (e.g., choreography, power moves, strength conditioning, flexibility, musicality). This information is essential to understanding the physical adaptations observed.
Recommendation: Please include a detailed breakdown of the training structure or acknowledge this absence as a study limitation.
Major Comment 2 – Unclear and Poorly Justified Measurement Methods
Key measurement instruments and procedures lack sufficient detail and validation. For example:
The photoelectric system used for sprint testing is not fully described (no model number or reference to validation studies).
The method for measuring the standing long jump is ambiguous (manual or electronic?).
Recommendation: Clearly describe all tools and their reliability. If manual methods were used, discuss potential measurement error.
Major Comment 3 – Inadequate Justification for the 400m Test
The inclusion of the 400-meter test as a performance measure for breakdancers lacks scientific justification. Breaking is an intermittent activity with bursts of explosive movement, not a continuous anaerobic-lactic effort.
Recommendation: Provide a literature-based rationale for including the 400m test or consider omitting it in future studies.
Major Comment 4 – Incomplete Statistical Justification
While the authors apply common statistical tests (t-test, ANOVA, Pearson correlation), the sample size is small (n=23), and multiple comparisons are conducted without any correction for type I error. Assumption testing (e.g., normality, homogeneity of variance) is not reported.
Recommendation: Report assumption testing, consider corrections for multiple comparisons, and explicitly discuss the limitations imposed by the small sample size and potential lack of statistical power.
The findings are relevant and directionally consistent with the hypotheses, but methodological and analytical issues weaken the confidence in the results. In particular, the lack of training content detail, questionable measurement procedures, and limited justification for some tests reduce the internal validity of the conclusions. These issues must be addressed for the findings to be credible.
This study tackles an important and under-researched topic—physical profiling in youth breakdancing. The inclusion of biological maturation is commendable, and the manuscript is well-organized. However, significant methodological concerns must be resolved before the paper is suitable for publication. The authors are encouraged to revise the manuscript thoroughly to improve clarity, rigor, and interpretative caution.
This manuscript explores the influence of biological maturation, anthropometric characteristics, and physical fitness variables on performance in young breakdancers at different competition levels. The study presents novel data on a population that has received limited scientific attention, especially given the sport's recent inclusion in the Olympic Games. The article is timely and addresses a clear knowledge gap.
The paper is generally well written and presents an appropriate structure. However, improvements are needed regarding methodological transparency, maturity assessment explanation, statistical interpretation, and practical implications. Several key areas lack clarity, including test battery justification and the definition of competitive level criteria.
The sample size justification is missing.
There is no power analysis or justification for including 23 participants. The small sample size may limit generalizability.
The definition of elite vs. sub-elite is potentially biased
Lines 82–84: Classification based solely on national ranking (cut-off at 16th place) may not be rigorous or internationally comparable.
The maturity assessment method lacks a limitations discussion.
Lines 104–114: The use of the Mirwald formula is acceptable but subject to known error margins, especially near PHV.
The test battery lacks sport-specific justification.
Lines 90–175: While the fitness tests are standard, they may not reflect the demands of freestyle breakdancing (e.g., creativity, flow, technical execution).
No inter-rater or test–retest reliability reported
For a study relying on field testing, the lack of measurement reliability is a concern.
Limited statistical power with multiple comparisons
Numerous ANOVAs and t-tests were performed, but no correction for Type I error (e.g., Bonferroni) is reported.
Correlation analysis lacks interpretative depth.
Figure 4 presents correlations but with minimal discussion on which variables are most relevant for talent identification.
Only one significant variable differentiates elite from sub-elite
Line 207: 1-minute sit-ups showed significant differences, but their relevance to breakdancing performance is unclear.
No longitudinal insights on maturity progression
The cross-sectional nature of the study limits the ability to infer causality or growth-related adaptations.
Training history not quantified in analysis.
While training exposure is described (Line 78–80), it’s not included in statistical models as a covariate.
Language and clarity
Several grammatical issues and awkward phrasing are present (e.g., Line 38 “breaking has gradually evolved...” repeated).
Discussion of generalizability is limited.
Participants are all elite Chinese male breakers. This limits applicability to females or other regions.
Conclusion lacks specificity
The suggestion to refine test batteries is broad.
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