Effect of Various Hydration Strategies on Work Intensity and Selected Physiological Indices in Young Male Athletes during Prolonged Physical Exercise at High Ambient Temperatures

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Dear authors,

I found this paper very interesting. Congratulations for your good work. The aim of the study was to investigate the effectiveness of different hydration strategies applied during exercise in high temperature and humidity and the impact of these strategies on work intensity assessment and selected physiological indicators in young males. Although it is a good work, I believe that some minor changes are necessary before accepting this work. I explained below the changes:

• Introduction: The introduction explains the importance of proper hydration during exercise in hot environments, and reviews the existing literature on the topic. It also states the objective and hypothesis of the study, and justifies its relevance and novelty. The introduction is well structured and grounded, but it could be improved by expanding a bit more on the theoretical framework and the conceptual bases of the research. For example, you could explain the physiological mechanisms of dehydration and thermoregulation, and the factors that influence them, such as exercise intensity, duration, and type, as well as environmental conditions, individual characteristics, and fluid composition.
• Materials and methods: This section describes in detail the design of the study, the participants, the measures and the procedures used to evaluate the effect of the different hydration strategies on physical performance and physiological indicators. It also specifies the statistical analyses performed and the ethical and pragmatic aspects of the research. This section is well written and organized, and allows to replicate the study with ease. However, it could be improved by including a table or a diagram that summarizes the design of the study and the variables measured, to facilitate the understanding of the reader.
• Results: This section presents the results obtained in the study, using tables, figures and text. It reports the mean values and the statistically significant differences of the variables studied, according to the hydration strategy, the test order and their interaction. This section is well elaborated and shows the results in a clear and precise way, but it could be improved by using more attractive and explanatory graphics, and avoiding unnecessary repetition of data between the text and the tables or figures. In my opinion, there are some tables that are too long and many figures, so you should check the norms of the journal.
• Discussion: This section discusses the results obtained in the study, comparing them with those of other similar studies and explaining the possible causes and consequences of the findings. It also points out the limitations of the study and draws the conclusions and practical implications of the research. This section is well argued and contextualized, but it could be improved by making a more integrative synthesis and highlighting the original contributions and recommendations for future research.

Author Response

Dear Reviewer,

Thank you very much for your time and valuable comments, which all have been considered and incorporated. The entire manuscript has been further linguistically revised by a native speaker. The detailed list of responses is given below. We hope that the modifications and explanation will be acceptable for you.

Yours sincerely,

Rydzik, corresponding author

I found this paper very interesting. Congratulations for your good work. The aim of the study was to investigate the effectiveness of different hydration strategies applied during exercise in high temperature and humidity and the impact of these strategies on work intensity assessment and selected physiological indicators in young males. Although it is a good work, I believe that some minor changes are necessary before accepting this work. I explained below the changes:

• Introduction: The introduction explains the importance of proper hydration during exercise in hot environments, and reviews the existing literature on the topic. It also states the objective and hypothesis of the study, and justifies its relevance and novelty. The introduction is well structured and grounded, but it could be improved by expanding a bit more on the theoretical framework and the conceptual bases of the research. For example, you could explain the physiological mechanisms of dehydration and thermoregulation, and the factors that influence them, such as exercise intensity, duration, and type, as well as environmental conditions, individual characteristics, and fluid composition.

The task of achieving and maintaining an ideal state of hydration during physical activity becomes increasingly challenging, depending on the type of sport, the nature of the activity, and the accessibility of the fluids. While optimal hydration is influenced by various factors, it can generally be described as the prevention of losses exceeding 2–3% of body mass during exercise, while also avoiding excessive fluid intake [McDermot]. survey of the performance of physical work in the heat showed that the best performance during prolonged work was achieved by replacing fluids equal to those lost in sweat (Pitts).

• Materials and methods: This section describes in detail the design of the study, the participants, the measures and the procedures used to evaluate the effect of the different hydration strategies on physical performance and physiological indicators. It also specifies the statistical analyses performed and the ethical and pragmatic aspects of the research. This section is well written and organized, and allows to replicate the study with ease. However, it could be improved by including a table or a diagram that summarizes the design of the study and the variables measured, to facilitate the understanding of the reader.

Thank you very much. This section has been modified.

• Results: This section presents the results obtained in the study, using tables, figures and text. It reports the mean values and the statistically significant differences of the variables studied, according to the hydration strategy, the test order and their interaction. This section is well elaborated and shows the results in a clear and precise way, but it could be improved by using more attractive and explanatory graphics, and avoiding unnecessary repetition of data between the text and the tables or figures. In my opinion, there are some tables that are too long and many figures, so you should check the norms of the journal.

Thank you very much. This section has been modified.

• Discussion: This section discusses the results obtained in the study, comparing them with those of other similar studies and explaining the possible causes and consequences of the findings. It also points out the limitations of the study and draws the conclusions and practical implications of the research. This section is well argued and contextualized, but it could be improved by making a more integrative synthesis and highlighting the original contributions and recommendations for future research.

Thank you very much. This section has been modified.

 

Reference:

McDermott, B.P.; Anderson, S.A.; Armstrong, L.E.; Casa, D.J.; Cheuvront, S.N.; Cooper, L.; Kenney, W.L.; O’Connor, F.G.; Roberts, W.O. National athletic trainers’ association position statement: Fluid replacement for the physically active. J. Athl. Train. 2017, 52, 877–895

Pitts, GC, Johnson, RE, and Consolazio, FC. Work in the heat as affected by intake of water, salt, and glucose. Am J Phys 142: 253–259, 1944. 30.

Reviewer 2 Report

Comments and Suggestions for Authors

Thank you for the opportunity to revise the current MS. Please find my comments and suggestions below, line by line.

Line 31: Typo, please amend.

Line 45: I don’t understand this phrase, please give this MS to a native ENG speaker.

Line 78: Same as above.

Line 90: This was defined years ago. Please remove this sentence.

Lines 103-4: Again, I understood your point, but not sure if this would be also true for somebody else reading your work. Therefore, please give this MS to a native speaker.

Line 115: Please develop a study hypothesis here.

Line 118: Again, here, ENG amended is needed as well.

Line 158: A test cannot determine anything, while a person running the test can. Poor ENG lang. skills.

Also, VO2 should be presented as V̇O₂, as this is the correct way to indicate flow, here and throughout the MS.

Why only VT2 and not VT1 ? Please explain

Line 280: Same here, this is not the level of ENG language suitable for peer rew. Journal.

Line 283: Redundant, its quite clear from the existing literature (e.g., Wingate application). Please remove.

Tables look outdated, do you really need to separate columns and rows ?

Formatting of the figures does not look good; picture resolution is poor. You need 300 dpi resolution at least.

Line 443: Typo, please amend.

In general, the discussion section could be shortened and main findings should be highlighted and compared to previous findings in a more elaborate way. Also, my advice to the authors is, please try to answer these two questions in your discussion: What is new and interesting about your study? Work your way around this to improve your discussion section.

Line 606: Ok, but by how much ? Your conclusions seem to be a bit vague, please support them with actual numbers you collected here.

 

Comments on the Quality of English Language

Please give this MS to a native ENG speaker. 

Author Response

Dear Reviewer,

Thank you very much for your time and valuable comments, which all have been considered and incorporated. The entire manuscript has been further linguistically revised by a native speaker. The detailed list of responses is given below. We hope that the modifications and explanation will be acceptable for you.

Yours sincerely,

Rydzik, corresponding author

 

Line 31: Typo, please amend.

Statistically significant differences in HR were observed between the no-hydration and water groups.

Line 45: I don’t understand this phrase, please give this MS to a native ENG speaker.

People who engage in sustained physical effort increase the excretion of water and electrolytes through sweat, which can affect heart and muscle function.

Line 78: Same as above.

Hydration of the body can be done by oral intake of fluids that are absorbed according to the tonic, volume and composition. The rehydration strategy should be continued after exercise, as the replacement of lost water and electrolytes is important in maintaining athletic performance. One of the main factors affecting the rehydration process after exercise is the composition and volume of liquid consumed

Line 90: This was defined years ago. Please remove this sentence.

Removed.

Lines 103-4: Again, I understood your point, but not sure if this would be also true for somebody else reading your work. Therefore, please give this MS to a native speaker.

The science of nutrition remains a complex subject that is constantly evolving and sometimes contradictory.

Line 115: Please develop a study hypothesis here.

It was assumed that isotonic hydration has a greater effect than water on physiological factors.

Line 118: Again, here, ENG amended is needed as well.

 

Line 158: A test cannot determine anything, while a person running the test can. Poor ENG lang. skills.

Physiological indicators were checked at the level of the second threshold of ventilation (VT2) and at the level of maximal oxygen uptake (VO2max).

Also, VO2 should be presented as V̇O2, as this is the correct way to indicate flow, here and throughout the MS.

Modified.

Why only VT2 and not VT1 ? Please explain

Line 280: Same here, this is not the level of ENG language suitable for peer rew. Journal.

The VO2 value was 49.7 ± 6.7 ml/min/kg.

Line 283: Redundant, its quite clear from the existing literature (e.g., Wingate application). Please remove.

Removed.

Tables look outdated, do you really need to separate columns and rows ?

Modified.

Formatting of the figures does not look good; picture resolution is poor. You need 300 dpi resolution at least.

Modified.

 

Line 443: Typo, please amend.

A slight increase was observed with water consumption compared to lack of hydration, and the lowest increase was with isotonic drinks.

In general, the discussion section could be shortened and main findings should be highlighted and compared to previous findings in a more elaborate way. Also, my advice to the authors is, please try to answer these two questions in your discussion: What is new and interesting about your study? Work your way around this to improve your discussion section.

 

Line 606: Ok, but by how much ? Your conclusions seem to be a bit vague, please support them with actual numbers you collected here.

 

Modified.

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

I would like to thank the authors for following my suggestions and comments. 

Comments on the Quality of English Language

I would like to thank the authors for following my suggestions and comments.