Effects of Exercise Type and Gameplay Mode on Physical Activity in Exergame

Round 1

Reviewer 1 Report

Summary: The paper presents an exergame aimed to investigate the effect of exercise type and gameplay mode physical activity performance. Different physical activities (e.g., Rest, Walk) were measured using Kinect and ECG. Why the study is interesting, the research design and data analysis fall short of standard analysis. The study is not well-motivated, the results and main takeaway are not well-presented, and the main contributions articulated. For example, the plots can be re-presented in a better and more understandable form. The repeated-measure ANOVA should involve all exercise types at once (Rest, Walk, Run, Tennis Single, Tennis Cooperation, Tennis Competition) since each participant performed all of them to prevent family-wise errors. Moreover, as part of the ANOVA, measurement method (Kinect vs ECG) should be a variable (factor). Hence, we would like to see F-values, p-values, degree of freedom (DF), main effects, and interactions in the overall and further ANOVAs. Below are some suggestions to improve the paper.

 

1. There is a need for proper copyediting of the paper, as some of the sentences are not well, correctly, or clearly worded.

2. In the literaure review (related work), you should identify the gaps in the existing studies and which of them your current work aims to address.

3. Was the study submitted and approved by an ethics board? Information about this should be in the paper.

4. “This experiment is a within-subject design in which one participant performed all types of exercises. All participants performed four types of single-person exergame (Rest, Walk, Run and Tennis) and additional two-people Tennis (Cooperation and Competition mode) with the random order.” What is the rationale for choosing the types of exercise and persuasive strategies (cooperation and competition).

5. “(Walk, Run, Tennis Single, Tennis Cooperation, Tennis Competition x 2 minutes relax and 3 minutes exercise x 2 times = 50 min) …”  The information conveyed here is not clear. Could you rewrite the sentence in a clearer form?

6. Could you provide the numerical values that indicate intensity of each exercise, e.g., Metabolic Equivalent (MET) coefficient value? For exampl, that of walk is about 4. In that regard, numerical analysis can be carried out, e.g., correlation between intensity and HR.

7. In Figure 4 and Figure 5, why are we using continuous lines to connect the variables on the X axis. What is the relationship between the X variables? Does their numerical value increase as we move from left to right along the X xis? I suspect bar chart may better suit the plot.

8. The conclusion is too long and looks/sounds like another background/introduction. You should make it short, e.g., a maximum of half a page. Moreover, it should focus on the main findings, their implications, and future work.

9. In Table 2, what does the bold numbers indicate. There should be a note at the bottom or top of the table indicating the meaning. Moreover, use the standard *, **, *** stars to indicate significance levels for p<0.05, p<0.01, and p<0.001, respectively. One star (p<0.1) should not be regarded as statistically significant.

10. What is the rationale for including the mean value of only Rest in Table 2 and Table 3, while omiting those of the other exercise types?

11. It is difficult to uncover the main takeaway of the paper. I will recommend that the authors enumerate the main takeway (finding) of the paper.

12. What are the limiations of the study and what are the contributions to knowledge.

 

Comment related to sentences

1. Exercise games, exergames, which combine both exercise and video gaming, train people in a fun and competitive manner to lead a healthy lifestyle. “exergames” should be in bracket – something like this: Exercise games (exergames).

2. “For example, when performing aerobics exercise in a group with an actual partner, the duration of exercise and satisfaction with exercise and willingness were high [8,9].” “Willingness” should be written in full: “willingness to exercise”.

3. “In this paper, we aims at evaluating the exercise effects according to the type of exer- 54 game and gameplay mode.” Should be “we aim to evaluate…”

4. “First, IRB explanation and consent form (5 minutes)…” Spell out “IRB” in full the first time you use it.

5. “Figure 1. Single subject playing Walk, Run, and Tennis.” Do you mean “Figure 1. Single subject playing Walk, Run, and Tennis games”? because Walk/Run as an activity or exercise cannot be played.

6. “To evaluate the exercise effect of the subjects…” Do you mean “To evaluate the effect of exercise type on the performance of subjects”? Kindly make it clearer.

7. “The sampling rate was once every 0.00039 seconds on the basis of measuring 2560(? = 2560) times per second. ” Why is 2560 repeated twice; isn’t it redundant? Same with “outputs 5400 ? = 5400) frames for each exercise session.”

8. “The method of evaluating heart rate variability with the ECG sensor can be divided into the time domain analysis and the frequency domain analysis. In the time domain, standard deviation of all NN intervals (SDNN), the square root of the mean of the sum of the squares of differences between adjacent NN intervals (RMSSD), Mean heart rate (Mean HR), and Max heart rate (Max HR), and in the frequency domain, power in low frequency range in normalized units (LF), power in high frequency range in normalized units (HF), and the ratio of absolute LF to absolute HF power (LF/HF ratio) were used. The description of the measured variables is as follows.” Can you spell out each acronym when first used, e.g., “NN”?

 

Author Response

Authors appreciate the reviewer's constructive comments and the associate editor's favorable decision. Please find the changes in the revision which are marked with colored letters.

Author Response File: Author Response.pdf

Reviewer 2 Report

Literature review is very limited: 10.3389/fpsyg.2022.829432; 10.1155/2022/2095514; 10.1007/s00520-021-06559-1; 10.1186/s13673-020-00256-4

10.3390/s22093531; 10.15758/ajk.2022.24.2.2; 10.1007/978-3-031-11438-0_18

 

Because comparable methods exist, the novelty should be better described. Furthermore, the text is severely lacking in technical specifics on how the system performed categorization, processing, what algorithms were used, and so on. In 3.3 and 3.4, just minimal information was presented, which appeared to be rather general.

 

The experiments could be adequately contextualized (the reader should not be left to assume that they will get their own conclusions). The experiments should be reported in greater detail (e.g. set up and carry out process, results in raw format, etc.). How was the model's accuracy assessed? By what standards? Expert understanding? Include a thorough statistical reliability study to demonstrate that the rebuilt model is accurate. Include complete exercise performance metrics. Add measure in overall effectiveness (read here: 10.1016/j.psychsport.2022.102266). Increase the computing performance in FLOPS.

 

Author Response

Authors appreciate the reviewer's constructive comments and the associate editor's favorable decision. Please find the changes in the revision which are marked with colored letters.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Still a very low number of references (only 21). You're missing a lot of works in your state of the art review.

I think it would be also benefitial to compare existing skeletal frameworks and models too.

For the other parts - the paper is now much improved. However, there is still no statistical validity analysis. Add proofs that results are statistically significant.

Also add more illustrations of the actual results (e.g figures 2, 3 and 4 as seen by your algorithm). Also illustrate ground troughts.

Paper does not say how you combated noise.

Author Response

Authors appreciate the reviewer's constructive comments and the associate editor's favorable decision. Please find the changes in the revision2 which are marked with blue colored letters.

Author Response File: Author Response.pdf

Round 3

Reviewer 2 Report

Thank you for reacting to my remarks. IMO the paper can now be accepted although I would still recommend adding more depth to the literature review. Also I would recommend getting MDPI's proof read services as there are some mistakes left in the language. No need to send for re-review.

Author Response

Authors appreciate the reviewer’s constructive comments and the associate editor’s favorable decision. 

According to the reviewer’s comments, we used MDPI’s proof read service and the proofread final version is uploaded.