Review for 10.1186/s12876-019-0936-x (2019)

Reviewer ’s report  
 
Title: High -intensity interval training and moderate -intensity continuous training in adults with 
Crohn’s disease: a pilot  randomised controlled trial  
 
Version: 0 Date: 05 Nov 2018  
 
Reviewer: Whitney Duff  
 
Reviewer's repo rt: 
 
Overall Comments:  
 
Exercise trials are desperately needed in individuals with IBD. It is interesting that the authors 
chose HIIT, considering the general recommendation for those with IBD to avoid high -intensity 
exercise (due t o potential for adverse gastrointestinal effects). However, without trials we have 
no evidence for or against these potential effects.  
 
It would be more acceptable to publish blood markers of inflammation in a separate manuscript 
if there were many signif icant differences found within that data. However, since no hypothesis 
testing was completed, and data is only represented as means (SD), this is obviously not the case. 
This data should be included in the current manuscript.  
 
Specific Comments:  
Line 62: This reference is about exercise for rheumatoid arthritis. Yes, an inflammatory disease - 
however, is otherwise not applicable as it is not an inflammatory disease that effects the 
gastrointestinal system. What are the most current guidelines/reco mmendations for IBD?  
 
Line 78: Why did you choose to exclude individuals with ulcerative colitis?  
 
Line 91: Please state with certification/designation of the individual's in charge of 
supervising/training  
 
Line 128: I see that RPE and %HRmax are reported  and appear to be in line with 'moderate -
intensity', but I am having a hard time believing that 35% Wpeak (50 -54W) elicited a 'moderate -
intensity' effort.  
 
Line 157: This seems like a contrived way of defining success. If I'm understanding this 
correctly,  success was 67% of the participants completed 67% of the sessions. What was this 
decision based on? Wouldn't 80% be typically more acceptable?  
 
Line 170: Although somewhat redundant with questionnaire name, list the outcomes measured 
via these questionna ires (i.e. QOL, fatigue, depression, anxiety), like how you did for disease 
status (via CDAI) above in Line 166.  
 
Line 182: Were participants blinded to the hypothesis (i.e. that the HIIT would be superior to 
MICT exercise on outcomes)? If so, please state  here. If not, please consider doing so for future 
trial. 
 
Line 224: Was the participant that started aerobic/strength training 3 -4d/wk excluded from 
outcome assessment?  
 
Line 234: Why were those with RA excluded, but not this participant with ankylosing 
spondylitis?  
 
Line 259: Please clarify what percentage of the 'illness' category was disease related illness.  
 
Line 332: Valuable feedback! Emphasize this when seeking funding for future studies.  
 
Line 356 -363: I am slightly confused by the planned future t rial intervention. It appears you 
wanted to do a combo intervention of HIIT/MCIT for a well -rounded aerobic intervention and 
then a control exercise group (i.e. flexibility). But then it's mentioned the intervention would 
include  a combination of aerobic,  resistance, balance and flexibility exercises in a 2 -arm trial 
(also discussed in Additional File 3). So, what is the other arm in the 2 -arm trial if flexibility is 
included in the intervention? Regardless, I would suggest doing a 3 -arm trial: Arm 1 = Aer obic 
combo of HIIT and MCIT (e.g. 2 days of HIIT and 1 of MCIT); Arm 2 = Strength combo of 
HIIT and lower intensity circuit (e.g. 2 days of HIIT strength and 1 lower intensity circuit); Arm 
3 = Flexibility and balance (e.g. combo of both 3 days per week, a s control/sham exercise 
group). Then expand inclusion criteria to include patients with CD and ulcerative colitis to assist 
with fulfilling the greater recruitment needs.  
 
Line 381 -382: Here is sounds as though the flexibility exercise is placebo, but pre vious statement 
it does not. Please clarify.  
 
Line 383: Consider including individuals with UC, which would increase recruitment potential.  
 
Are the methods appropriate and well described?  
If not, please specify what is required in your comments to the authors.  
 
Yes 
 
Does the work include the necessary controls?  
If not, please specify which controls are required in your comments to the authors.  
 
Yes 
 
Are the conclusions drawn adequately supported by the data shown?  
If not, please explain in your comments to the authors.  
 
Yes 
 
Are you able to assess any statistics in the manuscript or would you recommend an  
additional statistical review?  
If an add itional statistical review is recommended, please specify what aspects require further  
assessment in your comments to the editors.  
 
Not relevant to this manuscript  
 
Quality of written English  
Please indicate the quality of language in the manuscript:  
 
Acceptable  
 
Declaration of competing interests  
Please complete a declaration of competing interests, considering the following questions:  
 
1. Have you in the past five years received reimbursements, fees, funding, or salary from an  
organisation that may in any way ga in or lose financially from the publication of this  
manuscript, either now or in the future?  
 
2. Do you hold any stocks or shares in an organisation that may in any way gain or lose  
financially from the publication of this manuscript, either now or in the f uture?  
 
3. Do you hold or are you currently applying for any patents relating to the content of the  
manuscript?  
 
4. Have you received reimbursements, fees, funding, or salary from an organization that 
holds  or has applied for patents relating to the content of the manuscript?  
 
5. Do you have any other financial competing interests?  
 
6. Do you have any non -financial competing interests in relation to this paper?  
 
If you can answer no to all of the above, write 'I  declare that I have no competing interests' 
below.  If your reply is yes to any, please give details below.  
 
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