Acute Effects of Overload Running on Physiological and Biomechanical Variables in Trained Trail Runners
, Alberto Rubio-Peirotén 1,*, Silvia Cardiel-Sánchez 1, Pablo Díez-Martínez 1, Luis Enrique Roche-Seruendo 1 and Diego Jaén-Carrillo 2
Round 1
Reviewer 1 Report
Comments and Suggestions for Authors
Review of the paper entitled: Acute effects of overload running on physiological and biomechanical variables in trained trail runners, submitted in Applied sciences (MDPI)
General comments:
The authors asked trail runners to perform 3 incremental tests until exhaustion wearing 3 different weights (0, 5 or 10% of body mass) in each of them and measured V02, power and the cost of transport, among other variables. They observed that adding weight decreases the speed achieved at a given relative metabolic intensity and tends to increase the cost of transport.
Overall, the paper is clearly written, but I have several comments.
Major.
It is not clear which participants and in what conditions the participants failed to reach a VO2 plateau.
Box plots do not look like depicting normally distributed values but the authors used parametric tests.
It is not clear how power was calculated using the Stryd device or whether this device is suitable for research purposes.
specific or minor:
L 60. what does “improving the muscular elastic component” means? Do you mean, improve the storage-restitution of elastic energy?
L 65-66. Not sure this subject is largely unexplored. The effect of load carriage is not unexplored per se, e.g.:
Teunissen et al. 2007. J Exp Biol (2007) 210 (24): 4418–4427.
Silder et al. (2015). J biomech. 48(6), 1003-1008.
Puthoff, et al. (2006). Medicine and science in sports and exercise, 38(4), 746-752.
Liew et al. (2016). Gait & posture, 47, 74-79.
Equation1: For me power is in Watt, not in ml per kg and per unit of time. I guess this was computed using the amount of oxygen consumed (in ml of O2?) but don’t you need a conversion between the amount of O2 consumed and the amount of energy (in Joules)? Given the units presented in table 2 (different from that presented in figure 2), i.e., Joules per kg and per meter, you wanted to build an index reflecting the amount of energy per unit of distance. It is up to some scaling factors but as it is presented, it seems wrong.
L145. What do you mean when you say that the variables were determined independently by one investigator. Of course, it is independent if he/she is alone. A “completely blinded” manner, here also it is not clear. In clinical research there is his notion of blindness but the reviewer is not sure this applies here, and completely mean what?
Section statistics. I don’t understand why power was computed using the coefficient of correlation as the effect size because you used ANOVAs.
Section results: please indicate the degrees of freedom for the F values. 3 digits is generally enough for the F value.
The terms “responses” in discussion does not seem appropriate. These are variables were measured, they quantify the work done, the amount of energy consumed, but they are not responses of the organism.
The conclusion says that “Running with a weighted vest is a requirement in trail running.” but I don’t think that the data allow to reach this conclusion. If you want to say that people usually run with a vest, please consider revising the sentence.
Table 2: a strange symbol appears instead of “mean”.
Tables 3. These are the p-values? (not indicated)
Figure 2. Why some data have no distribution? i.e., the Speed (noted v, but you could write speed entirely) at VT1. This is not consistent with the values given in table 2.
L 178. Space.
L 2018. is it “on ventilatory threshold” or “ on variables measured at ventilatory thresholds”?
L 230. these results should be in section result, as well as the description of the subjects and conditions in which the maximal VO2 values were not achieved.
Author Response
Dear reviewer, thank you very much for the time invested in reviewing our study, which has allowed us to improve its quality. Please find attached the document with the responses and corrections to all your comments.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsThe manuscript is logically coherent when read in its entirety, and the overall experimental design structure is relatively complete. However, there are still some issues.
When using the weight vest, did the author consider that this study is specifically targeted at running? Although similar weight vests are used in general running exercises, if each pocket has a capacity of 200g, then for a subject weighing 70kg to increase their weight by ten percent, at least 35 such pockets would be needed to carry the additional weight. Therefore, I am curious about the type of vest the author used. Furthermore, I also believe that this may not align well with practical situations.
How should we understand the term "voluntary exhaustion"? Each subject's level or physical capability is different. Can we use heart rate or muscle electrical signals as criteria for assessing this standard?
In the results section, the author needs to provide a more detailed description and summary of the results presented in the charts and tables.
Author Response
Dear reviewer, thank you very much for the time invested in reviewing our study, which has allowed us to improve its quality. Please find attached the document with the responses and corrections to all your comments.
Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for AuthorsThank you for the opportunity to review this paper. The aim of the study was to evaluate the impact of running with a weighted vest, loaded with 5% and 10% of body mass, on the physiological and mechanical variables of trained trail runners. It is mostly clear paper, there is, however, issues that must be resolved before the study can be accepted for publication.
Several comments and suggestions for the authors, please kindly consider the following points and revise them:
- In the abstract in the "background" section: the authors only stated the aim of the study without referring to this background.
- line 36: „Over the last 10 years the number of participants in this sport has doubled.” - In all of Europe or just in some countries? There is no specific information on this.
- Editorial note (does not affect the quality of the manuscript): do not use spaces between individual items in references, e.g. there is [3, 4], [11, 12], [6, 14, 15], [11, 16, 17] etc., there should be [3,4], [11,12], [6,14,15], [11,16,17] etc.
- Did the authors also specify exclusion criteria?
- Line 100: „The research protocol was authorized by the Local Ethics Committee.” - please provide the Ethics Committee approval numer.
- At the beginning of the discussion it is unnecessary to repeat the aim of the research.
- Apart from the limitations, the authors could have identified the strengths of the study.
- Research articles usually do not use the word „we” and regularly use passive verbs.
Author Response
Dear reviewer, thank you very much for the time invested in reviewing our study, which has allowed us to improve its quality. Please find attached the document with the responses and corrections to all your comments.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Comments and Suggestions for AuthorsI thank the reviewer for their answer. I still have a few comments.
”It is not clear which participants and in what conditions the participants failed to reach a VO2 plateau”; Your answer is that the measures were “performed independently by one investigator in a completely blinded manner”. If it means that you don’t know, I don’t understand how you can analyze your data. I believe the reader should be informed about which conditions of load the data are wrong.
You said that 3 participants were removed (15 – 3 = 12) that 60% of participants failed to reach the criteria (0.6*12 ≅ 7) but the degrees of freedom for the error are 28, which is for 15 participants in 3 conditions. There is something unclear.
Equation 1. The computation of metabolic power should be presented.
“The physiological thresholds was blinded as to which test he was evaluating. It has been rephrased in
the text.” I can’t see where?
Regarding the r as an effect size measure. “It has been changed in the corresponding section”. No, it hasn’t.
The significant results should be highlighted in figure 2.
Author Response
Please find attached the document with the responses to your comments. Thank you.
Author Response File: Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for Authorsnone
Author Response
Thank you for your comments that have allowed us to improve the manuscript.
Reviewer 3 Report
Comments and Suggestions for AuthorsDziękuję autorom za dokonanie poprawek manuskryptu. Nie mam więcej uwag.
Author Response
Thank you for your comments that have allowed us to improve the manuscript.
Round 3
Reviewer 1 Report
Comments and Suggestions for AuthorsDear authors, thank you for you answers. The comment below is not critical to understand the results, therefore I will recommend to accept the paper.
Minor. Regarding the computation of the sample size, I still don’t understand why you use the correlation value r (“15 subjects was required to observe an effect size of r = 0.6”). If you used some software to compute this, you should mention it.
Author Response
Dear reviewer, thank you for your comment. We thought that we had removed all references to "r" in the text, but you were correct. It has now been definitively corrected, and the reference to G*Power 3.1.9.7 (University of Düsseldorf, Düsseldorf, Germany) as the program used for the a priori calculation has been added to the corresponding section. Once again, thank you for helping us improve the manuscript, and we apologize for this oversight.
