The Effects of Different Stretching Techniques Used in Warm-Up on the Triggering of Post-Activation Performance Enhancement in Soccer Players
, Stefan Stojanović 3, Ramazan Bayer 4, Tijana Purenović-Ivanović 3, Tomasz Pałka 5, Tadeusz Ambroży 6, Krzysztof Kasicki 7,*, Wojciech Czarny 8 and Łukasz Rydzik 6,*Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsDear Editor, thank you for the opportunity to review the article entitled: "The Effects of Different Stretching Techniques Used in Warming-Up on the Triggering of Post-Activation Performance Enhancement in Soccer Players". The study presented an interesting topic and relevance for the practice of the sport. However, some modifications are necessary.
1. The objective of the study in the text is clear, but the introduction is confusing. The authors cite several studies that investigated the topic. However, the connection between the research cited and the study proposal is confusing. But the objective is perfectly clear.
2. The methodology of the study is well described. Figure 1. Experimental Design Diagram is very well designed and makes it easier for the reader to understand. Regarding methodology, the article is very well described.
3. The results are presented and described in a satisfactory manner.
4. The Dynamic Stretching was found to be the most favorable among the proposed protocols. However, the discussion provides little information about possible mechanisms that differentiated these results from other proposed protocols. The discussion is short and it would be interesting to add a more detailed discussion about possible mechanisms.
Author Response
Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsThank you for the opportunity to review the manuscript by Kurak and colleagues investigating the impact of different warm-up stretching techniques on post activation potentiation in soccer players.
The manuscript is interesting although I have some comments that I feel must be addressed to improve the manuscript in order to meet the standard required for publication.
General
The term Post-Activation Performance Enhancement (PAPE) is more commonly known as Post-Activation Potentiation (PAP). The authors should acknowledge this at the first time of using the term, so that readers are aware they refer to the same phenomenon.
When data are presented throughout, I suggest reporting to a maximum of two decimal places only.
Abstract
Line 26: I suggest replacing “athletes” with “soccer players” to make this more specific to the study population.
Line 32: I suggest the word “and” in the sentence “stretching, and proprioceptive neuromuscular” should be “or”. The current wording could be confused that the participants performed all protocols together.
Introduction
Line 50-52: The authors should also highlight the important point regarding PAP(E), which is that the potentiation effect is believed to acutely improve muscular force production after a near-maximal contractile effort in the same muscle(s) group. This makes it clearer to non-expert readers exactly why the strategy may be useful for muscular output.
Line 63-64: The authors refer to research here but have not provided citations to direct the reader to the studies they refer to. Please add references.
Line 108: A clear aim is provided but it would be good practice to also include a hypothesis. What did the authors expect would be the outcomes of the study? This can be based on previous work referred to in the introduction.
Methods
Line 118-120: Participant characteristics are given twice, with different values. Lines 123-126 match the data in Table 1, but lines 118-120 are different data. Please remove whichever is not correct. Also, data from the Table should not typically be repeated in the text, so I suggest removing the table or simply referring to Table 1 in the text, rather than providing participant’s characteristics twice.
Line 132: I suggest the term “protocol” is better than “exercise” when referring to the 1RM.
Line 134-135: Were warm-up protocol sessions performed in a randomised order, or the same order for all participants? Please clarify, as this has potential to impact the results.
Line 136: Please remove “another”, as this can be confusing to the reader.
Line 138: As per previous comment, “an additional” is not required. This makes it sound as if all warm-ups were performed consecutively rather than on separate visits.
Line 145: The authors mention all warm-up procedures were performed at the same time of day. It would surely be more appropriate to state that all intervention sessions took part at the same time of day, as this includes the warm-up element and the performance testing.
Line 170-171: What rest periods were provided between attempts during the 1RM protocol? Were these standardised? Please specify.
Line 193-194: How many attempts were permitted at the jump test? If multiple, how did the authors define which to record, and what duration of rest was provided between attempts? Please clarify.
Line 203-204: This has been stated previously, so can be removed.
Line 211: Please give more detail of the dynamic stretching protocol, to allow researchers/practitioners to replicate this in their respective settings. Specifically, how many sets and reps, and/or how long was spent per stretching exercise within the 5-minutes duration.
Line 222, 224: Please use anatomical terminology and replace “bending” with “flexion/flexing”.
Lines 216-234: It would be useful to provide some graphical representation of the stretching exercises, perhaps as supplementary material. This would help non-experts understand the protocols better.
Line 236: What rest period was provided between sets? Please specify.
Line 244: Is this correct? A Bonferroni adjustment is a correction for multiple testing used to reduce the likelihood of Type 1 error (false positive results), rather than a post-hoc test. Please clarify the use of Bonferroni test better.
Results
Line 247: My interpretation is that the main aim of the study is to assess which warm-up aligns with the optimal PAPE output. If this is the case, those results should be presented first.
Line 251: Are these significantly different in any way? If not and/or if statistical analysis has not been performed, please clarify this.
Table 2: Data in the Tables shouldn't be replicated in the text (ease of reading is the justification for using tables). Please remove this data from the text and simply refer to Table 2.
Table 3: I would suggest that mean square, F and ES statistics are not required for presentation here. It would be better to just present the protocols along the side (top to bottom) and top (left to right) and cross-tabulate with the p-values to demonstrate all comparisons individually.
Line 262: The terminology here needs to be improved. If this shows that PAPE plus dynamic stretching was more effective regarding jump height than PAPE plus 5-minute pedalling, this should be stated more explicitly. The same applies for the other results.
Discussion
Line 273-277: Please be more specific on what favourable means, e.g dynamic stretching was more favourable for enhancing the effects of PAPE on lower-limb power performance. Also, p-values are not required to be repeated in the discussion.
Line 279-280: Perhaps this is a trend observed, but if statistical comparison was not performed on the RPE data then you cannot state that one had higher/highest difficulty versus others. Please adjust language used in the text, or perform the additional statistical analysis to investigate whether there were significant differences to report.
Line 284: The authors state that “The results we reached are not surprising”. This links to an earlier point regarding lack of hypothesis. If the authors can provide a hypothesis, this would be the ideal point to refer back and state that their findings were in line with their primary hypothesis.
Line 286: The phrase “we can claim” is not required, please remove.
Line 290-291: What might the physiological mechanism behind this be, e.g why would increased heart rate from high-speed dynamic stretching potentially improve performance better than low-speed dynamic stretching? Please specify.
Line 306: Does “increasing athletic performance” refer to acutely or as an adaptation? Please specify.
Line 308: Rather than “sports performance” I would refer to this as lower-limb power output/performance. “Sports performance” implies some specific aspect of soccer competition (e.g high-speed running in games) was studied, which was not the case.
Line 311: P-values not required in discussion.
Line 313-314: What effects did this study the authors refer to measure? I.e what did they measure after the stretching techniques to determine an effect?
Line 316: Is “sports performance” referring to performance during competition, or performance indicators such as jump tests etc. Please specify.
Line 320: The authors must mention that this was not statistically significant, if that was the case.
Line 322: The current study not measure fatigue. Do to so, techniques such as the interpolated twitch technique would be required to test voluntary muscle activation. Please amend this sentence, and potentially suggest the use of such techniques in future to quantify fatigue.
Line 327-331: Please write out as sentences rather than bullet-pointed list.
Conclusion
Line 343: This is true, but the first mention of injuries in the study. I would suggest the authors introduce the concept of injury and flexibility earlier in the manuscript in relation to stretching. I am also not sure this statement fits with the study entirely, as no assessment of injury and/or flexibility was conducted. This could be made as more of a general point within the discussion.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
Comments and Suggestions for AuthorsI am happy with the revisions and responses.
