theory goes : in 'normals' joints are held in their place by the ligaments- in us due to ligaments being stretchier/longer the muscles have to take on part/or all of that job=they have to work more/harder=they get quicker/easier fatigued and sore
it's also thought that it's poss that apart from being more prone to noticable obvious injuries, we might be prone to 'plentiful micro injuries' (things like tiny tiny strains/tears etc that arent obvious) which then also cause soreness/pain and of course need repair/healing time
it's also thought poss that with time these 'plentiful micro injuries' may be/or be part of what leads to the malfunctioning of the pain signaling system=the chronic pain syndromes that so many of us suffer
I am not aware of any scientific studies that have been done to prove these 'theories'- but I heard them from prof g who has spent his life dealing with HMS/EDS-
so taking his decades of experience and my personal experience into account...
me thinks you'd better think twice/thrice if you really want to continue full contact boxing
ps : 'depleted collagen'- although the exact problem with our collagen isnt known as yet- thinking is that it's more likely a case of "faulty collagen" or "wrong ratio between collagen and other "building fibres/materials"