Now the dust has settled and sanity has appears to have returned to the listing I add my contribution to the subject of handlbars !.
I have always used both wide and narrow depending on which bike I consider they suit best .Whilst selecting different machines , changes in frame size , their geometry it all adds up to personel choice whether I use either. Another thought is the bars bends and reach and depth plus the raised randonee type all important choices in pleasure and competative riding. I never given a thought to breathing side of the debate but always considered taking care of my arms, back and neck regions.
To take another view beyond the choice for which bar to use, another consideration must be the length and height of stem and added to this not forgetting the other important positioning of the saddle in conjunction with the front end dimensions. Nothing in my view can be more important that these adjustments should be left to the individual person and the machine they ride!
Safe riding and always keep your heads up on those rides.
Doug Smith
North Dorset
UK