Apple Puree as a Natural Fructose Source Provides an Effective Alternative to Artificial Fructose Sources for Fuelling Endurance Cycling Performance in Males

Round 1

Reviewer 1 Report

This paper compared apple puree to a glucose/fructose (2:1) solution as a source of carbohydrate supplementation during endurance exercise, using nine athletes and showing no difference between the two solutions in performance tests or in terms of gastrointestinal disturbances at a carbohydrate dose of 60 g/h. The study convincingly demonstrated that runners could utilize even natural foods such as apple puree for carbohydrate supplementation during exercise.

1) line 126: It states that the sample was placed in a 50mL syringe, but please state the dose volume per 15 minutes for the two solutions.

2) The experiment shows that there is no difference between the two solutions at 60 g/h. What results do you expect at 90 g/h?

 

Author Response

Comments and Suggestions for Authors

This paper compared apple puree to a glucose/fructose (2:1) solution as a source of carbohydrate supplementation during endurance exercise, using nine athletes and showing no difference between the two solutions in performance tests or in terms of gastrointestinal disturbances at a carbohydrate dose of 60 g/h. The study convincingly demonstrated that runners could utilize even natural foods such as apple puree for carbohydrate supplementation during exercise.

Thanks for your time reviewing our paper and comments to help improve our manuscript, which we feel is now much improved.

• line 126: It states that the sample was placed in a 50mL syringe, but please state the dose volume per 15 minutes for the two solutions.

Thanks for the comment. This information is now included line 145

2) The experiment shows that there is no difference between the two solutions at 60 g/h. What results do you expect at 90 g/h?

Thanks, we have added sentences into the discussion but based on previous study findings we would not expect a difference in performance, but GI symptoms may be elevated with the higher dosage.

Reviewer 2 Report

The paper “  Apple puree as a natural fructose source provides an effective  alternative to artificial fructose sources for fuelling endurance cycling performance in males” compared cycling performance and GI comfort of two different fructose sources (fruit and artificial) ingested during exercise. The text and results presented in the paper are interesting but have copious amount of flaws. So the manuscript is unacceptable in its present form

1.       Please add a paragraph of apple puree as a natural fructose source in introduction explaining concentration of fructose in apple puree and explaining its health benefits

2.       Please add novelty of your study at the end of introduction

3.       How do you select cyclist parameter like age, cycling hours and experience for your study

4.       Results in section 3.2 should be compared with other similar studies

5.       Please elaborate in detail that why there is no difference between different trials in  Fluid Balance Measures

6.       Section 3.6 you are giving simple explanation of your statistical software. You are not explaining your results neither you are comparing them with other studies

7.       Section 3.7 Please explain your results in detail

8.       Conclusion should contain the values of best results

9.       Some references should be added from journal of Nutraceuticals

1   Some references are old which needs to be updated

   There are many grammatical errors please revise it from native speaker

 

Author Response

artificial fructose sources for fuelling endurance cycling performance in males” compared cycling performance and GI comfort of two different fructose sources (fruit and artificial) ingested during exercise. The text and results presented in the paper are interesting but have copious amount of flaws. So the manuscript is unacceptable in its present form

Thanks for your time reviewing our paper and comments to help improve our manuscript, which we feel is now much improved.

1. Please add a paragraph of apple puree as a natural fructose source in introduction explaining concentration of fructose in apple puree and explaining its health benefits

Thanks for comment. We have added in additional information into the introduction.

2. Please add novelty of your study at the end of introduction

We have amended the last paragraph of the introduction to emphasise the novel aspects of the study.

3. How do you select cyclist parameter like age, cycling hours and experience for your study

18 to 45 years is the age range approved by Loughborough University Ethics Committee. We wanted participants who were regularly cycling each week to ensure they were able to complete 2h preload plus TT on the bike and that there would not be any training effects. For example, perform the TT faster in the second trial as they were fitter. Participants had to be used to consuming carbohydrate during exercise. This was to try and ensure the reported GI symptoms were not exacerbated due to participants not being used to consuming carbohydrate whilst exercising.

Lines 87-90 describe the study inclusion criteria and then lines 93-94 describe the participants who volunteered to participate in the study and demonstrating they have met the study inclusion criteria.  

4. Results in section 3.2 should be compared with other similar studies

“Results: Provide a concise and precise description of the experimental results, their interpretation as well as the experimental conclusions that can be drawn”

The author guidelines for the journal state (see above) results are to be descriptive. Comparisons with previous studies are contained in the discussion section.

5. Please elaborate in detail that why there is no difference between different trials in Fluid Balance Measures

There were no differences in sweat rate, dehydration accrued or thirst scores suggesting participants did not feel the need to drink more in one trial and therefore there were no differences in fluid balance. The exercise intensity was also the same between trials so we wouldn’t anticipate any changes.

We have added a sentence into the discussion to help with clarity.

6. Section 3.6 you are giving simple explanation of your statistical software. You are not explaining your results neither you are comparing them with other studies

Same response as point 4. Study comparison is included in the discussion (see para starting line 353)

7. Section 3.7 Please explain your results in detail

Thanks for the comment. We have added further information into the section.

8. Conclusion should contain the values of best results

Thanks, we have added in time trial performance data into the conclusion.

9. Some references should be added from journal of Nutraceuticals

Nutraceuticals does not have articles on carbohydrate sources and exercise performance or apple so there is nothing appropriate for us to cite. However, we are undertaking follow-up research (nearly completed) which will lead to rapid citations of this paper.

10.  Some references are old which needs to be updated

We have cited articles that support our statements or quoted original articles which will explain why there are some older articles. An old article is not necessarily a bad one. For example, the scales we use are from older articles, so we need to cite the original manuscripts. We also include the most up-to-date papers in the are too.

   There are many grammatical errors please revise it from native speaker

All authors are native English speakers, who combined have published >150 scientific articles in peer-reviewed journals. We are confused by this comment as we have proofread the manuscript again for errors and there are virtually none, in our opinion. Some amendments have been made. If you could highlight the specific sections that contain poor grammar we will happily attend to these. 

Round 2

Reviewer 2 Report

The Paper is revised well and is worthy of publication