Round 1

Reviewer 1 Report

It is well written review. It is easy to read. I don't have any comments. 

Author Response

Thank you for your review

Reviewer 2 Report

The authors have reviewed the literature on intradialytic cycling and its health benefits. The manuscript is well-written and interesting for the readers of the journal however it would be important to add the table with all the methods that has been used to increase physical activity in dialysis patients including wearing the pedometers or accelerometers, add a second table with a list of advantages and risks/limitations related to intradialytic cycling and modifications of this method. I would also appreciate the algorithm showing the practical approach (guideline) to dialysis patients aimed to increase his physical activity,  

Author Response

We have added a table (Table 1) which describes the primary types of exercise interventions that have been implemented in hemodialysis patients, including selected citations for each exercise mode and a brief comment on each. Please note that this is not meant to be an exhaustive list of every type of intervention that has been done but is a thorough summary of the major types of interventions, as well as a few novel intervention approaches. 

We have added a table as requested (Table 2) highlighting advantages and Disadvantages of different approaches to exercise that have been prescribed for dialysis patients.  Thank you for this suggestion.

We are unaware of any specific algorithms or guidelines that have been used to prescribe exercise in dialysis patients as you have requested.  Several guidelines regarding exercise in dialysis have been published, and we have referenced several of these in the manuscript.  These include recently published guidelines from the UK (42), Australia (29), and KDOQI (25).  Please note that these guidelines are roughly similar to physical activity guidelines for healthy adults and those with chronic disease that have been published elsewhere. 

Reviewer 3 Report

Review for the manuscript entitled “Next Steps for Intradialytic Cycling Research”.

This review summarizes issues related to the evidence for Intradialytic Cycling that are still insufficient. Its problem to be solved in the future appeared to be the creation of an environment for intervention by exercise professionals and life planners.

The content seems significant in a future where end-stage renal disease is increasing. On the other hand, the reviewer would like to see the following points added:

Exercise therapy may even be useful in dialysis patients. On the other hand, the reviewer thinks that the target group that would benefit from exercise therapy should be clarified. For example, the benefits of exercise therapy may differ depending on age, presence or absence of diabetes / cerebro-cardiovascular disease, etc. It should also describe the characteristics of dialysis patients for whom exercise is not recommended.

This review summarizes issues related to the evidence for Intradialytic Cycling that are still insufficient. Its problem to be solved in the future appeared to be the creation of an environment for intervention by exercise professionals and life planners.

The content seems significant in a future where end-stage renal disease is increasing. On the other hand, the reviewer would like to see the following points added:

Exercise therapy may even be useful in dialysis patients. On the other hand, the reviewer thinks that the target group that would benefit from exercise therapy should be clarified. For example, the benefits of exercise therapy may differ depending on age, presence or absence of diabetes / cerebro-cardiovascular disease, etc. It should also describe the characteristics of dialysis patients for whom exercise is not recommended.

Author Response

Thank you for this comment.  Indeed, there are several contraindications to exercise in dialysis patients that have been described in various guidelines.  These include electrolyte abnormalities, excessive IDWG, lung congestion and peripheral edema (references 23).   We have added a statement regarding these contraindications on lines 76-81.  Having said that, there is an abundance of data indicating that exercise is very safe for HD patients, even those with significant frailty or other comorbidities, as we also indicate in this section (references 25 – 27).   Indeed, this is one of the central discussion points in our manuscript.   Specifically, we are making the argument that a one-sized fits all approach, which is what intradialytic cycling for the most part, is inappropriate or ineffective.   As such, we have argued that more personalized “patient-centric” exercise prescriptions should be implemented, as they are more flexible and more thoroughly consider the limitations and characteristics (i.e., comorbidities) of each participant. 

Round 2

Reviewer 2 Report

My criticism has been addressed in the revised manuscript