Effects of Exercise Intensity Differences in Forest Therapy Programs on Immunoglobulin A and Dehydroepiandrosterone Levels in Older Adults

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Good clear abstract, well written submission. Clearly laid-out reasoning for this study focus and demographic group in the Intro.  Good description of the included measures and criteria for separating MFEG and HFEG. A thorough write-up and good design.  There are some minor recommendations to improve the manuscript for acceptance:

1.     It is not clear what the scope is of reference #1.  Is this 84.1%/54.9% only in Korea.  Please clarify what ref 1 refers to.

2.     Provide reference for the sentence “The rise in 33 the number of older adults with chronic diseases is predicted to cause an increase in na- 34 tional healthcare expenditure and the social burden”

3.     Provide references for the section “Exercise acts as an exogenous stressor. The body responds to these external stimuli 51 to activate functions for maintaining homeostasis, and through this process, anti-aging 52 and immune functions improve. However, over-exercising can have adverse effects; thus, 53 regulating exercise intensity according to individual physical ability is of paramount im- 54 portance. Elite athletes, in some cases, exercise at an intensity that exceeds their limit of 55 ability to improve their performance skills.”

4.     Provide references for “Adults secrete approx- 100 imately 2 g of IgA daily, and IgA deficiency is more likely to cause respiratory infections. 101 Older adults are considered a high-risk group for infectious diseases as they are suscepti- 102 ble to infectious diseases because of a decrease in mucosal immune defense.”

5.     ALSO, is there a rationale presented why IgA might be a useful marker for measuring impact/efficacy of MFEG/HFEG?  Reference….

6.     Similarly, it is curious that IgA and DHEA were selected as outcomes, instead of more traditional markers of benefit of physical activity, e.g. Cardiovascular markers such as heart rate, blood pressure, HRV, etc… especially when the literature shows significant data regarding the positive impact on these of Forest Therapy.  Recommend acknowledging these other biomarkers in your Introduction and then (possibly) explaining that IgA and DHEA are less frequently utilized markers that need more study (hence your submission..)

7.     The sentence “Exercise intensity measurements for five sessions from sessions 11 to 20 and the av- 197 erage value“ is unclear.  Please clairify (for reproducability purposes)what determination was made to include which of the five sessions between sessions 11 to 20.

8.     IgA changes are reported well, however it is curious that MFEG was the only group with significant IgA changes when beginning at such a significantly lower level (24.50) compared to the other groups (38.59, 40.34).  This could be included in the limitations section as a potential alternative explanation for the reported data.

9.     Description of the experimental variable’s effect on outcomes seems to rely primarily/solely on the physical exertion/uphill slope of the terrain experienced.  There does not appear to be any mention of the typical therapeutic/restorative aspects of Forest Therapy (i.e. biophilia, stress reductions, phytoncides, mindfulness, shinrin-yoku, etc….) and their effect on IgA and DHEA.   Are these aspects purposefully not included in the current manuscript and if so, is there a reason for this.  Otherwise, is it useful to include these aspects in sections of the manuscript such as Introduction or Discussion? Otherwise this experiment seems to be describing more about the effects of Exercise Intensity in general on outcome measures, rather than the effects of “Forest Therapy”.

10.  The section ”Moreover, continuous forest exercise over 360 20 sessions helps maintain the elevated levels of IgA and DHEA without a rapid decline. 361 Based on these results, we recommend a moderate-intensity forest exercise for 120 362 minutes of forest exercise activities, conducted twice per week, to facilitate changes in IgA 363 and DHEA in older adults. Further, if a long-term forest therapy regimen is used, we rec- 364 ommend incorporating adequate relaxation regiments as well. “ seems more like a study conclusion than discussion.  Consider moving to Conclusion. 

11.  Recommend including some reference material on “Green Exercise” e.g. Jules Pretty, Jo Barton, etc…

12. There is not much discussion of the potential impact of the other Forest Therapy aspects (i.e. Breathing Training, Cognitive Enhancement program, etc...) on outcome measures.  May not matter since these aspects were present in both the MFEG and HFEG groups, but it would be appropriate to acknowledge their contributions to IgA & DHEA (compared to the DAG) group), rather than assign all outcome data on just the Physical Activity aspect of the experimental groups.

Comments for author File: Comments.pdf

Author Response

1. It is not clear what the scope is of reference #1. Is this 84.1%/54.9% only in Korea. Please clarify what ref 1 refers to.

Response: Please note that this is a situation in Korea. However in Korea, 84.1% of older adults have a chronic disease, and 54.9% have two or more chronic diseases [1]

2. Provide reference for the sentence “The rise in 33 the number of older adults with chronic diseases is predicted to cause an increase in na- 34 tional healthcare expenditure and the social burden”

Response: [2-3]Reference materials are provided

3. Provide references for the section “Exercise acts as an exogenous stressor. The body responds to these external stimuli 51 to activate functions for maintaining homeostasis, and through this process, anti-aging 52 and immune functions improve. However, over-exercising can have adverse effects; thus, 53 regulating exercise intensity according to individual physical ability is of paramount im- 54 portance. Elite athletes, in some cases, exercise at an intensity that exceeds their limit of 55 ability to improve their performance skills.”

Response: [10],[11],[12] Reference materials are provided

4. Provide references for “Adults secrete approx- 100 imately 2 g of IgA daily, and IgA deficiency is more likely to cause respiratory infections. 101 Older adults are considered a high-risk group for infectious diseases as they are suscepti- 102 ble to infectious diseases because of a decrease in mucosal immune defense.”

Response: [29].[30]Reference materials are provided.

5. ALSO, is there a rationale presented why IgA might be a useful marker for measuring impact/efficacy of MFEG/HFEG? Reference….

Response: IgA is the most abundant immunoglobulin among antibodies secreted from the mucous membrane [28]. Intensive exercise means weakening immune function by reducing immunoglobulins, so strategic forest exercise management is necessary to prevent im-munosuppression caused by exercise [29].

6. Similarly, it is curious that IgA and DHEA were selected as outcomes, instead of more traditional markers of benefit of physical activity, e.g. Cardiovascular markers such as heart rate, blood pressure, HRV, etc… especially when the literature shows significant data regarding the positive impact on these of Forest Therapy. Recommend acknowledging these other biomarkers in your Introduction and then (possibly) explaining that IgA and DHEA are less frequently utilized markers that need more study (hence your submission..)

Response: Meanwhile, cardiovascular indicators such as HRV, blood pressure, heart rate, and Co-tisol have been usefully used as biomarkers to reveal the benefits of forest treatment. IgA and DHEA are less used biomarkers in forest therapy research. However, as an ac-tive forest therapy activity, forest walking exercise needs to reveal the benefits of forest therapy by evaluating its impact on more diverse biomarkers. The use of saliva is preferred in various studies because it can be collected safely and easily in a non-invasive way without requiring specialized skills.

 

7. The sentence “Exercise intensity measurements for five sessions from sessions 11 to 20 and the av- 197 erage value“ is unclear. Please clairify (for reproducability purposes)what determination was made to include which of the five sessions between sessions 11 to 20.

Response: There were participants who took five measurements during odd-numbered sessions and some who took five measurements during even-numbered sessions. The exercise intensity was the average of 5 sessions. Average exercise intensity was defined as the average intensity of all activities performed during 120 minutes.

8. 8. IgA changes are reported well, however it is curious that MFEG was the only group with significant IgA changes when beginning at such a significantly lower level (24.50) compared to the other groups (38.59, 40.34). This could be included in the limitations section as a potential alternative explanation for the reported data.

Response: We've included it in the limitations section

9. Description of the experimental variable’s effect on outcomes seems to rely primarily/solely on the physical exertion/uphill slope of the terrain experienced. There does not appear to be any mention of the typical therapeutic/restorative aspects of Forest Therapy (i.e. biophilia, stress reductions, phytoncides, mindfulness, shinrin-yoku, etc….) and their effect on IgA and DHEA. Are these aspects purposefully not included in the current manuscript and if so, is there a reason for this.  Otherwise, is it useful to include these aspects in sections of the manuscript such as Introduction or Discussion? Otherwise this experiment seems to be describing more about the effects of Exercise Intensity in general on outcome measures, rather than the effects of “Forest Therapy”.

Response: The slope of a forest is a unique healing factor that only a forest can provide, as every place is unique and not the same. This special feature provides a special exercise experience to those walking in the forest. I believe that the uniqueness of the forest movement is the effect of forest therapy, which is as important as any other factor in the forest. Therefore, we evaluated the impact of the topographical factors of the forest, excluding other forest healing factors (plant factors, climatic factors, phytoncides, social factors, sounds, etc.).

10. The section ”Moreover, continuous forest exercise over 360 20 sessions helps maintain the elevated levels of IgA and DHEA without a rapid decline. 361 Based on these results, we recommend a moderate-intensity forest exercise for 120 362 minutes of forest exercise activities, conducted twice per week, to facilitate changes in IgA 363 and DHEA in older adults. Further, if a long-term forest therapy regimen is used, we rec- 364 ommend incorporating adequate relaxation regiments as well. “ seems more like a study conclusion than discussion. Consider moving to Conclusion.

Response: We have moved to the conclusion.

11. Recommend including some reference material on “Green Exercise” e.g. Jules Pretty, Jo Barton, etc…

Response: We found out that Jules Pretty and Jo Barton were conducting a lot of research on the green movement, and We received a lot of help from them.

12. There is not much discussion of the potential impact of the other Forest Therapy aspects (i.e. Breathing Training, Cognitive Enhancement program, etc...) on outcome measures. May not matter since these aspects were present in both the MFEG and HFEG groups, but it would be appropriate to acknowledge their contributions to IgA & DHEA (compared to the DAG) group), rather than assign all outcome data on just the Physical Activity aspect of the experimental groups.

Response: Lastly, various healing factors such as the abundance of oxygen in the forest, pleasant climate, indirect sunlight, and plant essential oil, as well as social and psychological positive factors composed of forests, affect physiological changes. Future studies are expected to reflect the influence of forest healing factors and expand to studies on the effects of psychological factors on changes in IgA and DHEA.

Reviewer 2 Report

Comments and Suggestions for Authors

This paper is good, with strong methodology and relevant analyses and their interpretations. I would like to suggest some ideas how to improve the paper.

1. Please add more keywords for better indexing.

2. Please add references, lines 38, 60-65, 68-74, 86-89, etc. Please justify your ideas.

3. Please indicate when the study was conducted.

4. Please provide relevant information in Data Availability Statement, Funding. In the Acknowledgments, you could thank participants of this study.

5. Table 1: Please indicate between what groups (1 and 2 and/or 3) there were differences.

6. Table 1: Theme 1 should be also described in the paper.

7. Lines 134-136: When did you provide these sessions? In the morning? What time? And when: Period of the year (Spring? Summer etc)?

8. Please use zeroes before full stops in figures. See published papers in this journal and how they used zeroes

9. Figure 6: Please indicate periods in weeks in each step.

10. Please indicate effect size of all analyses (where applicable).

11. Table 6: a<b, a<c etc. are not understandable. Please reconsider. Do not provide abbreviations you can omit them. a,b,c should be replaced by Baseline, 5 weeks, End. Occam's razor: "Entities must not be multiplied beyond necessity".

12. Figure 7 and 8: Time 1-3 should be deciphered.

13. Table 7: you have no here results of p < 0.01**. Thus, "p < 0.01**" should be deleted. Please recheck all tables.

14. Discussion: Long paragraphs are unwanted, and one-sentence paragraphs are also undesirable. You could also provide subsections here, and separate Practical Implications or Recommendations, Limitations of the Study.

15. As for limitations and future directions, I believe that mentioning of psychological variables would be beneficial.

Author Response

1. Please add more keywords for better indexing.

Response: IgA, DHEA keywords have been added.

2. Please add references, lines 38, 60-65, 68-74, 86-89, etc. Please justify your ideas.

Response:  References [15].[17].[18] have been added

3. Please indicate when the study was conducted.

Response: Therefore, in this study, a regular forest exercise program was designed for older adults with 2 sessions per week for 10 weeks in urban forests in 2020.

4. Please provide relevant information in Data Availability Statement, Funding. In the Acknowledgments, you could thank participants of this study.

Response: This research was supported by the Korea Forestry Promotion Institute (grant no. 2018124A00-1920-AB01) funded by the Korea Forest Service

5. Table 1: Please indicate between what groups (1 and 2 and/or 3) there were differences.

Response: Differences between groups are shown in the table.

6. Table 1: Theme 1 should be also described in the paper.

Response: The average age of participants was DAG=78.89, MFEG=76.84, and HFEG=73.75. There was a difference between groups (p=.010) between DAG and HFEG in average age. Regarding gender, 4 women and 13 men were recruited for DAG, 4 women and 9 men for MFEG, and 6 women and 6 men for HFEG. The average height between groups was DAG=151.86, MFEG=154.54, and HFEG=160.85, and there was a difference between DAG and HFEG (p=.036). Body weight was DAG=57.55, MFEG=59.09, HFEG=64.94, and there was no difference between groups. BMI, which indicates obesity, was DAG=25.34, MFEG=24.83, and HFEG=24.89, and there was no difference between groups. Table 1 presents the physical development status of the participants. Table 1 presents the Physical Development Indicators of participants.

7. Lines 134-136: When did you provide these sessions? In the morning? What time? And when: Period of the year (Spring? Summer etc)?

Response: The forest exercise program included breathing exercises, walking exercises, strength exercises, and cognitive strengthening programs in the forest from September to November. It was conducted twice a week for 10 weeks, from 10:00 AM to 12:00 PM, for 120 to 130 minutes

8. Please use zeroes before full stops in figures. See published papers in this journal and how they used zeroes

Response: I'm sorry, but I didn't understand.

9. Figure 6: Please indicate periods in weeks in each step.

Response: The modified design was entered into Figure 6

10. Please indicate effect size of all analyses (where applicable)

Response: All effect sizes were entered

11. Table 6: a<b, a<c etc. are not understandable. Please reconsider. Do not provide abbreviations you can omit them. a,b,c should be replaced by Baseline, 5 weeks, End. Occam's razor: "Entities must not be multiplied beyond necessity".

Response: We replaced it with baseline, week 5, and end

12. Figure 7 and 8: Time 1-3 should be deciphered.

Response: We replaced it with baseline, week 5, and end

13. Table 7: you have no here results of p < 0.01**. Thus, "p < 0.01**" should be deleted. Please recheck all tables.

Response: Confirmed after completion of deletion

14. Discussion: Long paragraphs are unwanted, and one-sentence paragraphs are also undesirable. You could also provide subsections here, and separate Practical Implications or Recommendations, Limitations of the Study

Response: Thank you for your detailed guidance.

15. As for limitations and future directions, I believe that mentioning of psychological variables would be beneficial.

Response: Lastly, various healing factors such as the abundance of oxygen in the forest, pleasant climate, indirect sunlight, and plant essential oil, as well as social and psychological positive factors composed of forests, affect physiological changes. Future studies are expected to reflect the influence of forest healing factors and expand to studies on the effects of psychological factors on changes in IgA and DHEA

Reviewer 3 Report

Comments and Suggestions for Authors

Please expand on the literature in the introduction.  The introduction lacks items from the literature that relate to the positive effects of walking in the forest, e.g., by different age groups, in different parts of the world, or concerning different types of activities in forest areas. 

Figure 2: Please leave a gap between photos to make them more readable. 

 

The methodology and results are clearly written.

In the discussion in the first paragraph, please remove the repetition from the methodology. Please focus on the specifics that came out in the author's study and compare them with studies by other researchers. 

Author Response

1. Please expand on the literature in the introduction. The introduction lacks items from the literature that relate to the positive effects of walking in the forest, e.g., by different age groups, in different parts of the world, or concerning different types of activities in forest areas.

Response:  Unlike exercise on flat ground, the irregular incline of the uphill slope of the mountain forest improves not only aerobic exercise but also anaerobic capacity[8]. The uphill slope of the mountain forest generates muscle resistance, increases the range of joint movement, and greatly affects muscle contraction and elasticity. It improves body flexibility and balance strength in elderly people [9]. This therapeutic effect occurs as a result of walking on forested terrain, and forest exercise is expected to improve health and play a preventive role against disease.

2. 2. Figure 2: Please leave a gap between photos to make them more readable.

Response: The photo spacing has been corrected

3. The methodology and results are clearly written.

Response: Thank you very much.

4. In the discussion in the first paragraph, please remove the repetition from the methodology. Please focus on the specifics that came out in the author's study and compare them with studies by other researchers.

Response: Repeated methodologies were eliminated and summarized in the conclusion.

Reviewer 4 Report

Comments and Suggestions for Authors

The article is highly relevant from the point of view of attracting older people to systematic physical exercise. This is one of the most topical issues in view of the high rate of ageing in various countries. The use of modern methods to analyse the effects of physical activity on the human body, based on the assessment of changes in salivary hormone levels, is impressive.

The article would be more scientifically valuable if the details of the exercise sessions were described for possible use in other studies. The change in heart rate under the influence of exercise should be specified as an additional criterion for analysis. The study should have been extended to include more analysis of the exercise experience of older people and other outdoor populations. Add data from the last five years.

- It is not desirable to use abbreviated words in the abstract.

- The abstract does not sufficiently disclose the results and conclusions of the article.

- line 62 indicate exactly in which studies the question of the influence of load on professional athletes was studied.

- line 71 - 74 should provide information whether these conclusions were made by the authors themselves or whether these conclusions were confirmed by other researchers.

- It is necessary to agree the purpose of the work line 11 -12, 90 - 92, 111 - 113.

- In the introduction it is necessary to disclose the existing experience of other researchers on the organisation of forest walks for people of different ages, to indicate the directions to be considered in the article.

- «Table 1.  Physical characteristics of participants»  the title of the table should be corrected, this table reflects physical development indicators

- It is necessary to indicate who approved the research programme. 

- There is a question of increasing the physical load in the high-intensity exercise group, both in terms of distance and height.

- Figure 5. can be omitted

- Missing reference to the description of the saliva analysis method, Karvononen method

- line 339-344 the duration of high intensity exercise should be harmonised with table 2.

- The description should be supplemented with information on how the physical activity parameters changed during the exercise in each group.

- It was necessary to provide information about the motor experience of the participants before the start of the study. How the fitness level of the study participants was taken into account in determining the appropriate level of physical activity. Indicate whether the participants were at risk of cardiovascular disease.

- In the conclusions write the recommended parameters of physical activity (line 418 - 419). It is more complete to present the results on the dynamics of the studied parameters in different groups of study participants.

- It was rational to present the dynamics of heart rate at each type of load. To present the recommended values of heart rate at load and rest.

- The description of activities (forest walk exercises) should be supplemented with information about the nature of physical activity, for example, interval or uniform.

- The references to sources No. 1 should be clarified, and the need to use the reference to source No. 8 in the context of the study should be clarified.

- refine the presentation of mean and standard deviation data for samples that do not follow the normal distribution law.

Author Response

1. The article would be more scientifically valuable if the details of the exercise sessions were described for possible use in other studies. The change in heart rate under the influence of exercise should be specified as an additional criterion for analysis. The study should have been extended to include more analysis of the exercise experience of older people and other outdoor populations. Add data from the last five years.

Response: Have attached details of the exercise session and references on forest walking.

2 It is not desirable to use abbreviated words in the abstract.

Response: Abbreviations have been removed

3. The abstract does not sufficiently disclose the results and conclusions of the article.

Response:  The abstract has been supplemented.

4. line 62 indicate exactly in which studies the question of the influence of load on professional athletes was studied.

Response: [15] References are provided.

5. line 71 - 74 should provide information whether these conclusions were made by the authors themselves or whether these conclusions were confirmed by other researchers.

Response: [18] References are provided.

6. It is necessary to agree the purpose of the work line 11 -12, 90 - 92, 111 - 113.

Response: Thank you very much.

7. In the introduction it is necessary to disclose the existing experience of other researchers on the organisation of forest walks for people of different ages, to indicate the directions to be considered in the article.

Response:  Content has been modified: The form of forest exercise was more effective in increasing SOD for removing blood lipids and free oxygen related to cardiovascular disease than indoor exercise, and melatonin related to antioxidants and immunity of physiological functions [22]. Middle-aged men's 12-week forest walking exercise showed physiological stabilization of blood pressure and nervous system function, reduction of lipid peroxides, and increase of antioxidants, and psychological stability of emotional state and recovery of depression [23]. The forest walking movement can play a role in reducing the cost of the healthcare system while also helping to increase the welfare of participants. [24]. Working out in the forest can increase nerve cells, protecting the nerves and recovering from brain diseases [25].

8. Table 1.  Physical characteristics of participants»  the title of the table should be corrected, this table reflects physical development indicators

Response: Table 1. title changed; Physical Development Indicators of participants

9. It is necessary to indicate who approved the research programme.

Response: The research approval number has been entered in the Institutional Review Board Statement.

10. There is a question of increasing the physical load in the high-intensity exercise group, both in terms of distance and height.
11. Missing reference to the description of the saliva analysis method, Karvononen method

Response:  I modified the content Analysis was performed on an ELISAReader (BioTek, VT, USA) device using ELISA Kit (DRG, NJ, USA) reagents. Saliva samples were analyzed using enzyme-linked immunosorbent assay, a method of measuring antigen or antibody levels using an antigen–antibody reaction with an enzyme as a marker.

 

The DAG did not undergo any treatment, and thus, exercise intensity was not measured. Exercise intensity in the experimental group was measured using Polar430 (Polar Electro Oy, Finland). Pola430 calculates exercise intensity by measuring the subject's heart rate. Pola430 inputs the subject's date of birth, gender, height, and weight and measures the individual's exercise intensity. The formula for calculating maximum heart rate is to subtract the subject's age from 220 (220 - subject's age).

12. line 339-344 the duration of high intensity exercise should be harmonised with table 2

Response: (such that the high-intensity exercise regimen was shorter than the moderate-intensity exercise regimen. With the amount of exercise set at equivalent levels, moderate-intensity (55% VO2R) and high-intensity (70% VO2R) were effective on DHEA levels)=> This is an analysis of another author's research method. This part reveals that there are differences in the authors and methods of this study, and that this led to different results. Please note that it cannot be harmonized with Table 2.

13. The description should be supplemented with information on how the physical activity parameters changed during the exercise in each group.

Response: Unfortunately, no post-hoc measurements were made for physical variables

14. It was necessary to provide information about the motor experience of the participants before the start of the study. How the fitness level of the study participants was taken into account in determining the appropriate level of physical activity. Indicate whether the participants were at risk of cardiovascular disease.

Response: Before starting the study, we did not obtain information about the participants' exercise experience, and only their experience of participating in the forest healing program was reviewed. Participants self-examined their individual physical abilities while walking in the forest, and during the 1 to 5 sessions of exercise control during the program, they were guided to adapt to forest walking. We acknowledge our failure to review participants' risk for cardiovascular disease.

15. 15. In the conclusions write the recommended parameters of physical activity (line 418 - 419). It is more complete to present the results on the dynamics of the studied parameters in different groups of study participants.

Response: We present guidelines for adjusting the daily exercise time to 30-60 minutes, 3-5 a Week with exercise at medium intensity (60HRmax) starting at low intensity (40-50HRmax) and gradually increasing forest exercise programs for the elderly. If you proceed with high intensity exercise(70HRmax), it is recommended to include 20 to 30 minutes of daily exercise time and sufficient rest and recovery period so that the body can more comfortably adapt to the physical needs of the exercise. The findings of this study provide important insights on how to advance forest therapy programs specifically designed for the elderly population.

16. It was rational to present the dynamics of heart rate at each type of load. To present the recommended values of heart rate at load and rest.

Response: Thank you for your detailed guidance. In the conclusion, the appropriate heart rate and amount of exercise for elderly people are suggested.

17. The description of activities (forest walk exercises) should be supplemented with information about the nature of physical activity, for example, interval or uniform.

Response: The forest exercise program included breathing exercises, walking exercises, strength exercises, and cognitive strengthening programs in the forest from September to November. It was conducted twice a week for 10 weeks, from 10:00 AM to 12:00 PM, for 120 to 130 minutes. Participants learned breathing training methods from sessions 1 to 5, and a forest healing instructor conducted a light forest walk to help participants adapt to forest walking. From sessions 6 to 10, participants were instructed to walk at a faster pace. From sessions 11 to 20, participants selected a forest walking path suited to their physical strength and did a walking exercise for 40 minutes. Muscular exer-cise (Band) was performed once from sessions 1 to 5, repeated twice from sessions 6 to 10, and repeated 3 times from sessions 11 to 20.

18. The references to sources No. 1 should be clarified, and the need to use the reference to source No. 8 in the context of the study should be clarified.

Response: Source number 8 has been changed to number 16, and is a paper referring to the definition of aging.

19. 19. refine the presentation of mean and standard deviation data for samples that do not follow the normal distribution law.

Response: The mean and standard deviation have been corrected

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

Thank you for reconsidering the paper. As many comments were taken into account, however, some of them still remain. Therefore, I invite the authors to reconsider the paper according to the previous and new comments, which are described below.

1. Section "2. Materials and Methods" should be included.

2. My previous comment: Please indicate effect size of all analyses (where applicable).

Response: All effect sizes were entered.

My new comment: The authors did not present the effect for all analyses (ANOVA, paired t-tests, etc.). I encourage the authors to reconsider this comment with more attention.

3. Zeros before full stops in numbers should be used. Please reconsider this one more time. E.g., not "p < .001", but use correct "p < 0.001".

4. Please use asterisks in tables correctly. Please check all the tables and reconsider. For example, Table 1 has asterisks (*), but in the notes these asterisks were not deciphered.

5. Additionally, I encourage the authors to thank the reviewers for their efforts in evaluating papers. Your responses to a reviewer were not started with "Thank you" or smth similar. Thanking reviewers is a sign of good scientific practice, which is especially relevant for high-quality journals such as Forests. A lack of thanking in responses can seems disrespectful and reviewers may treat this negatively. Therefore, it would be beneficial for the authors to include some thanksgiving comments to reviewers.

 

Author Response

We would like to appreciate the reviewer’s contribution and provide valuable comments on our manuscript. We have revised based on the comments from the reviewer and tried to improve the quality of the manuscript.

1. Section "2. Materials and Methods" should be included.

Response:  The subtitle "2. Materials and Methods" inserted.

2. The authors did not present the effect for all analyses (ANOVA, paired t-tests, etc.). I encourage the authors to reconsider this comment with more attention.

Response: We reanalyzed the data to obtain the Cohen's- d value and Anova's effect size η2, and inserted in the manuscript (Tables 5, 6, 7, 8).

3. Zeros before full stops in numbers should be used. Please reconsider this one more time. E.g., not "p < .001", but use correct "p < 0.001".

Response: Thank you for your thoughtful comments. I modified the table by putting zeros in all the tables.

4. Please use asterisks in tables correctly. Please check all the tables and reconsider. For example, Table 1 has asterisks (*), but in the notes these asterisks were not deciphered.

Response: Thank you for your thoughtful comments. We revised the table, and added note to decipher the asterisks.

Reviewer 3 Report

Comments and Suggestions for Authors

The work in its current form, after corrections, is suitable.

Author Response

We would like to appreciate the reviewer’s contribution and provide valuable comments on our manuscript. We have revised based on the comments from the other reviewers and tried to improve the quality of the manuscript.

Reviewer 4 Report

Comments and Suggestions for Authors

It is not desirable to use abbreviated words in the abstract (IgA, DHEA; line 23, 26, 28)

Analyse more research from the last five years. For example: https://www.mdpi.com/2413-8851/7/3/85 

 

Author Response

We would like to appreciate the reviewer’s contribution and provide valuable comments on our manuscript. We have revised based on the comments from the reviewer and tried to improve the quality of the manuscript.

1. It is not desirable to use abbreviated words in the abstract (IgA, DHEA; line 23, 26, 28)

Response: We replaced the abbreviation into full words.

2. Analyse more research from the last five years. For example: https://www.mdpi.com/2413-8851/7/3/85

Response:  We surveyed more research conducted in recent years included in Introduction (lines 104-114) in Discussion (lines 390-394).

Round 3

Reviewer 2 Report

Comments and Suggestions for Authors

Thanks for improvements. The paper seems good.

 

Please correct the use of abbreviations. For example, line 18: abbreviation of "dehydroepiandrosterone(DHEA)" was introduced, but below in line 26 this abbreviation was not used. This comment applies to all abbreviations, therefore, please check them. 

There are a lot of typos, e.g. a lack of spaces etc.

Author Response

We would like to appreciate your kind comments on our manuscript. We revised the followings based on the comments.

 

1. Please correct the use of abbreviations. For example, line 18: abbreviation of "dehydroepiandrosterone(DHEA)" was introduced, but below in line 26 this abbreviation was not used. This comment applies to all abbreviations, therefore, please check them. 

Response:  We introduced the full form and abbreviations at the first, then used abbreviations.

2. There are a lot of typos, e.g. a lack of spaces etc.

Response: We corrected spacing between the text, the reference entry number, and spacing between math symbols, letters, and numbers.

Reviewer 4 Report

Comments and Suggestions for Authors

Best wishes to the authors of the article. 

Author Response

We would like to appreciate your kind comments on our manuscript. Thank you for your contribution.

Round 4

Reviewer 2 Report

Comments and Suggestions for Authors

Thanks for improvements. The authors addressed my comments satisfactorily.