Dynamic Analysis of Cortisol Hormone, Alpha-Amylase Enzyme, and Blood Lactate Levels during a Rowing Ergometer 6 km Race

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

-I think that the title of the paper does not adequately explain the problem of the research itself. I think it would be better if the title were specifically related to cortisol and amylase, because realistically there are no cardiovascular parameters examined in the paper to draw attention to that in the title.

-In the abstract and Introduction, the authors state amylase as a hormonal parameter, which should be corrected to an enzyme or metabolic parameter

-In materials and methods section authors state 11 junior ans senior male rowers. Are there 11 rowers in total or are there 11 juniors and 11 seniors. Adjust in total if so.

-In the entire work, check and correct that there is a period instead of a comma to indicate the decimal place.

-In Table 1, correctly indicate the significance z K-S test, greater than 0.200.

-Although the authors state that there are not many works on this topic, the interrelation between cortisol and amylase should be explained in the introduction and discussion. In this way, it would contribute to the understanding of why the authors chose these two parameters for research, in addition to lactate.

     

Author Response

I think that the title of the paper does not adequately explain the problem of the research itself. I think it would be better if the title were specifically related to cortisol and amylase, because realistically there are no cardiovascular parameters examined in the paper to draw attention to that in the title.

Comment: Dear reviewer, thank you very much for Your suggestion. We have changed the title of the paper and it now reads “Dynamic Analysis of Cortisol Hormone, Alpha-amylase Enzyme and Blood Lactate Levels during a Rowing Ergometer 6 km race”.

 

In the abstract and Introduction, the authors state amylase as a hormonal parameter, which should be corrected to an enzyme or metabolic parameter.

Comment: Thank you very much for your suggestion. Alpha amylase enzyme is now categorized as a metabolic parameter alongside blood lactate, while cortisol hormone remained categorized as a hormonal parameter as before, in both the abstract and introduction sections.

 

In materials and methods section authors state 11 junior and senior male rowers. Are there 11 rowers in total or are there 11 juniors and 11 seniors. Adjust in total if so.

Comment: Thank you for Your comment. There are 11 rowers in total. We put “junior and senior” in brackets to make the text more clear.

It now reads: “This study included 11 (junior and senior) male rowers from HVK Gusar Split (age 17,2 ±2,31 years on average)”.

 

In the entire work, check and correct that there is a period instead of a comma to indicate the decimal place.

Comment: Thank you for your suggestion. It is checked and updated as You mentioned.

 

In Table 1, correctly indicate the significance z K-S test, greater than 0.200.

Comment: Thank you for noticing. The last column of the table has been updated and the value is changed to 0.200.

 

Although the authors state that there are not many works on this topic, the interrelation between cortisol and amylase should be explained in the introduction and discussion. In this way, it would contribute to the understanding of why the authors chose these two parameters for research, in addition to lactate.

Comment: Thank You very much for Your suggestion. We added additional information regarding the interrelation of the 2 variables.

The text in the introduction section now reads: “Both cortisol and alpha-amylase are convenient markers for stress research, indicating the body’s sympathetic activity. Both markers could be non-invasively measured in saliva allowing sampling in various settings”.

The text in the discussion section now reads: “Since both cortisol hormone and alpha-amylase enzyme indicate sympathetic activity they reported similar competitive environment dynamics”.

Reviewer 2 Report

Comments and Suggestions for Authors

The introduction presented by the authors is in line with the objective of the research and correctly presents the formulation of the objective. However, we recommend the authors to revise and update some of the contents. The document only presents 25.8% of citations and references from the last 5 years. The debate would be to raise this percentage to at least 50%.

In reference to the section on materials and methods, the authors give an excellent description of the process, with good measures to prevent contamination of the samples extracted.

Possibly the great limitation of the stage is the small sample with which the research is carried out and, moreover, of only one sex. It is possible that the research would have been more complete with a larger sample and covering both sexes.

With reference to the statistics used, they are in accordance with the objective of the study and according to the results presented in the following section.

The results are clearly presented and the tables and figures presented by the authors help in the interpretation of the results. However, the descriptive analysis should be extended with other results beyond the mean and standard deviation. Also, in table 1, the legend does not include some abbreviations, such as K-S (p). It is recommended to extend the descriptive analysis and present broader results.

It is also recommended to use the same number of decimal places in all the figures in Table 1.

In relation to the discussion and along the same lines as the introduction, the authors provide a complete discussion, adjusted to the objective of the research but, however, again with a lack of citations and references from the last 5 years, which penalises the quality of this section.

The authors also fail to mention some of the other limitations of the study beyond biomarkers, as I have already mentioned. It is recommended that they carry out a more in-depth analysis of the limitations of the study as well as possible future lines of research.

Comments on the Quality of English Language

Minor editing of English language required

Author Response

The introduction presented by the authors is in line with the objective of the research and correctly presents the formulation of the objective. However, we recommend the authors to revise and update some of the contents. The document only presents 25.8% of citations and references from the last 5 years. The debate would be to raise this percentage to at least 50%.

Comment: Dear Reviewer, thank You very much for the suggestion. We have additionally extensively studied the literature and added more recent research as listed below:

• Holt, A. C., Aughey, R. J., Ball, K., Hopkins, W. G., & Siegel, R. (2020). Technical determinants of on-water rowing performance. Frontiers in sports and active living, 2, 589013.
• Treff, G., Winkert, K., & Steinacker, J. M. (2021). Olympic rowing—maximum capacity over 2000 meters. Dtsch. Z. Sportmed, 72, 203-211.
• Glancy, B., Kane, D. A., Kavazis, A. N., Goodwin, M. L., Willis, W. T., & Gladden, L. B. (2021). Mitochondrial lactate metabolism: history and implications for exercise and disease. The Journal of Physiology, 599(3), 863-888.
• Caplin, A., Chen, F. S., Beauchamp, M. R., & Puterman, E. (2021). The effects of exercise intensity on the cortisol response to a subsequent acute psychosocial stressor. Psychoneuroendocrinology, 131, 105336.
• Zurek, G., Danek, N., Żurek, A., Nowak-Kornicka, J., Żelaźniewicz, A., Orzechowski, S., ... & Kowal, M. (2022). Effects of dominance and sprint interval exercise on testosterone and cortisol levels in strength-, endurance-, and non-training men. Biology, 11(7), 961.

However, we are aware that a certain part of the references are older than five years, and the reason for this is the lack of research on this topic in the recent period. We firmly believe that this is another strength of our research

In reference to the section on materials and methods, the authors give an excellent description of the process, with good measures to prevent contamination of the samples extracted.

Comment: Thank you very much for your comment. We appreciate your observation.

 

Possibly the great limitation of the stage is the small sample with which the research is carried out and, moreover, of only one sex. It is possible that the research would have been more complete with a larger sample and covering both sexes.

Comment: Dear reviewer, thank You very much for Your comment. A small sample is a great limitation but there is little we could have done about it since we included all competitive level junior and senior level rowers from HVK Gusar Split. Rowing sport in Croatia is not the most popular compared to some other sports, and rowing clubs are experiencing low numbers of junior and especially senior level rowers. Furthermore, with the rowing sport being mostly occupied by men in general, there are even less junior and senior-level women that we could have included in our research. Thank you one more time for Your observation, we hope that you understand our problem.

 

With reference to the statistics used, they are in accordance with the objective of the study and according to the results presented in the following section.

Comment: Thank You very much for Your recognition.

The results are clearly presented and the tables and figures presented by the authors help in the interpretation of the results. However, the descriptive analysis should be extended with other results beyond the mean and standard deviation. Also, in table 1, the legend does not include some abbreviations, such as K-S (p). It is recommended to extend the descriptive analysis and present broader results.

Comment: Thank You for noticing the lack of descriptive parameters. We have added minimum, maximum and median values and it is all presented in Table 1 (Please see the results section for more details). Also, the legend is amended and includes descriptive parameter’s abbreviations.

It is also recommended to use the same number of decimal places in all the figures in Table 1.

Comment: Thank You very much for Your suggestion. It has been updated as you mentioned.

 

In relation to the discussion and along the same lines as the introduction, the authors provide a complete discussion, adjusted to the objective of the research but, however, again with a lack of citations and references from the last 5 years, which penalises the quality of this section.

Comment: Dear Reviewer, thank You for this observation. Similarly like in the introduction part,  we have additionally analyzed recent literature and added studies listed below:

• Becker, L., Semmlinger, L., & Rohleder, N. (2021). Resistance training as an acute stressor in healthy young men: associations with heart rate variability, alpha-amylase, and cortisol levels. Stress, 24(3), 318-330.
• Glancy, B., Kane, D. A., Kavazis, A. N., Goodwin, M. L., Willis, W. T., & Gladden, L. B. (2021). Mitochondrial lactate metabolism: history and implications for exercise and disease. The Journal of Physiology, 599(3), 863-888.

 

 

 

The authors also fail to mention some of the other limitations of the study beyond biomarkers, as I have already mentioned. It is recommended that they carry out a more in-depth analysis of the limitations of the study as well as possible future lines of research

Comment: Dear reviewer, thank you very much for your comment. We updated both sections as you mentioned.

For the study limitations, the text now reads: “Finally, the greatest limitation of the study could be seen through the small sample consisting of only 11 rowers, due to the lack of Croatian junior and senior club rowers in general”.

As for the future lines of research, we updated the text and it now reads: “Future lines of research should aim to include psychological and anabolic variables to complement current findings of the situational stress of a 6km ergometer race, as well as include the wider sample and female rowers”.

Reviewer 3 Report

Comments and Suggestions for Authors

This manuscript reports on a method of monitoring of metabolic and hormonal responses of the atheletes during 6km rowing sports, to determine individual efforts and stress that athletes endure and help optimize the training load. 

In total, this interesting study may find wide application in community of sports training. The paper is well designed, performed, and written. I think it suitable for publication in Applied Sciences. 

Author Response

This manuscript reports on a method of monitoring of metabolic and hormonal responses of the atheletes during 6km rowing sports, to determine individual efforts and stress that athletes endure and help optimize the training load. 

In total, this interesting study may find wide application in community of sports training. The paper is well designed, performed, and written. I think it suitable for publication in Applied Sciences. 

Comment: Dear reviewer, thank You very much for Your review, we are happy and content that we earned your approval.

Reviewer 4 Report

Comments and Suggestions for Authors

Please take note of the following text:

The paper's problem is intriguing because the authors attempted to gather data on a 6km rowing race using an ergometer, whereas the standard race distance is 2km. It would be beneficial if the conclusion mentioned this fact and explained its practical implications, particularly for coaches - for instance, when it is more suitable to use a 2km test versus a 6km test. Overall, the methodology is well executed. The abstract provides essential information about the work and its results, adhering to the journal's requirements. The keywords are fitting and accurately represent the work. In the introduction, the authors effectively explain relevant terms and substantiate their explanations with appropriate references from international journals. The selected references are suitable for all sections of the work and support the authors' perspectives, particularly in the discussion section. The methodology and choice of statistical analyses are sound. The results are properly interpreted and substantiated by tables and graphs. In the subsequent discussion section, the results are compared with similar research, contributing further value. The conclusions align with the obtained results and discussion. I believe that the paper has the potential to interest a broader readership and offers practical value. Therefore, I recommend accepting the paper with minimal corrections as mentioned throughout the rest of the text.

Line 191 Since the standardized warm-up protocol included 20 minutes of steady-state low-intensity rowing, we can explain the drop in post-warm-up cortisol and alpha-amylase levels through the effects of the low-intensity aerobic stimulus.

This text changes without We in a sentence

Because the standardized warm-up protocol included 20 minutes of steady-state low-intensity rowing, the decline in cortisol and alpha-amylase levels after the warm-up may be explained by the effects of the low-intensity aerobic stimulus.

Line 200 Considering the fact that higher alpha-amylase levels indicate sympathetic nervous system activation and parasympathetic inhibition we can speculate that rhythmic steady-state warm-up activity resulted in increased parasympathetic activity, reducing athletes' stress and decreasing alpha-amylase levels.

Since higher alpha-amylase levels indicate sympathetic nervous system activation and parasympathetic inhibition, it can be speculated that the rhythmic steady-state warm-up activity resulted in increased parasympathetic activity, reduced stress in the athletes, and decreased alpha-amylase levels

Line 187 Taking into consideration different physiological backgrounds among the variables, we can infer that the 6 km rowing ergometer race triggered 188 different hormonal and metabolic responses.

Considering the different physiological backgrounds among the variables, it could be concluded that the 6 km rowing ergometer race elicited different hormonal and metabolic responses.

Line 247-253 This text changes without We in a sentence

Limitations of this study come from the fact that we didn’t collect any data about athletes’ anabolic response in terms of measuring salivary testosterone as we did with cortisol and alpha-amylase. We also didn’t include any data regarding athletes’ psychological responses measuring their state of anxiety or self-confidence before the race to evidence possible influence on biomarker levels. Finally, baseline values are absent for studied biomarkers from the “non-race” days, although we measured baseline salivary and blood biomarker values at the time of arrival.

The limitations of this study include the absence of data on athletes' anabolic response, as salivary testosterone was not measured, unlike cortisol and alpha-amylase. Additionally, there is a lack of data regarding athletes' psychological responses, such as anxiety or self-confidence before the race, which could potentially influence biomarker levels. Furthermore, baseline values for the studied biomarkers on non-race days were not included, despite baseline salivary and blood biomarker values being measured upon arrival.

Author Response

The paper's problem is intriguing because the authors attempted to gather data on a 6km rowing race using an ergometer, whereas the standard race distance is 2km. It would be beneficial if the conclusion mentioned this fact and explained its practical implications, particularly for coaches - for instance, when it is more suitable to use a 2km test versus a 6km test. Overall, the methodology is well executed. The abstract provides essential information about the work and its results, adhering to the journal's requirements. The keywords are fitting and accurately represent the work. In the introduction, the authors effectively explain relevant terms and substantiate their explanations with appropriate references from international journals. The selected references are suitable for all sections of the work and support the authors' perspectives, particularly in the discussion section. The methodology and choice of statistical analyses are sound. The results are properly interpreted and substantiated by tables and graphs. In the subsequent discussion section, the results are compared with similar research, contributing further value. The conclusions align with the obtained results and discussion. I believe that the paper has the potential to interest a broader readership and offers practical value. Therefore, I recommend accepting the paper with minimal corrections as mentioned throughout the rest of the text.

Comment: Dear reviewer, thank You very much for Your review, we are glad and content that You recognize and approve our work.

 

Line 191 Since the standardized warm-up protocol included 20 minutes of steady-state low-intensity rowing, we can explain the drop in post-warm-up cortisol and alpha-amylase levels through the effects of the low-intensity aerobic stimulus.

This text changes without We in a sentence

Because the standardized warm-up protocol included 20 minutes of steady-state low-intensity rowing, the decline in cortisol and alpha-amylase levels after the warm-up may be explained by the effects of the low-intensity aerobic stimulus.

Comment: Thank You very much for Your suggestion. We have updated the text and it now reads:” Because the standardized warm-up protocol included 20 minutes of steady-state low-intensity rowing, the decline in cortisol and alpha-amylase levels after the warm-up may be explained by the effects of the low-intensity aerobic stimulus”.

 

Line 200 Considering the fact that higher alpha-amylase levels indicate sympathetic nervous system activation and parasympathetic inhibition we can speculate that rhythmic steady-state warm-up activity resulted in increased parasympathetic activity, reducing athletes' stress and decreasing alpha-amylase levels.

Since higher alpha-amylase levels indicate sympathetic nervous system activation and parasympathetic inhibition, it can be speculated that the rhythmic steady-state warm-up activity resulted in increased parasympathetic activity, reduced stress in the athletes, and decreased alpha-amylase levels

Comment: Thank You very much for Your suggestion. We have updated the text and it now reads:” Since higher alpha-amylase levels indicate sympathetic nervous system activation and parasympathetic inhibition, it can be speculated that the rhythmic steady-state warm-up activity resulted in increased parasympathetic activity, reduced stress in the athletes, and decreased alpha-amylase levels”.

 

Line 187 Taking into consideration different physiological backgrounds among the variables, we can infer that the 6 km rowing ergometer race triggered 188 different hormonal and metabolic responses.

Considering the different physiological backgrounds among the variables, it could be concluded that the 6 km rowing ergometer race elicited different hormonal and metabolic responses.

Comment: Thank You very much for your comment. The text now reads: “Considering the different physiological backgrounds among the variables, it could be concluded that the 6 km rowing ergometer race elicited different hormonal and metabolic responses”.

 

Line 247-253 This text changes without We in a sentence

Limitations of this study come from the fact that we didn’t collect any data about athletes’ anabolic response in terms of measuring salivary testosterone as we did with cortisol and alpha-amylase. We also didn’t include any data regarding athletes’ psychological responses measuring their state of anxiety or self-confidence before the race to evidence possible influence on biomarker levels. Finally, baseline values are absent for studied biomarkers from the “non-race” days, although we measured baseline salivary and blood biomarker values at the time of arrival.

The limitations of this study include the absence of data on athletes' anabolic response, as salivary testosterone was not measured, unlike cortisol and alpha-amylase. Additionally, there is a lack of data regarding athletes' psychological responses, such as anxiety or self-confidence before the race, which could potentially influence biomarker levels. Furthermore, baseline values for the studied biomarkers on non-race days were not included, despite baseline salivary and blood biomarker values being measured upon arrival.

Comment: Thank You very much for Your comment. We have updated the text and it now reads:” The limitations of this study include the absence of data on athletes' anabolic response, as salivary testosterone was not measured, unlike cortisol and alpha-amylase. Additionally, there is a lack of data regarding athletes' psychological responses, such as anxiety or self-confidence before the race, which could potentially influence biomarker levels. Furthermore, baseline values for the studied biomarkers on non-race days were not included, despite baseline salivary and blood biomarker values being measured upon arrival”.