CJinNM,
A little humor helps to keep us sane!

We have to be able to laugh at ourselves.
Re the diapers, in some brands the absorbent mat is better bonded to the back sheet and less prone to separate or fragment. Tena Slip and Dry 24/7 are two such diapers. I was going to recommend the Tena Slip Maxi for exercise (I still have a stock of the plastic-backed ones), as well as the Unique Wellness Superio Signature (not the original Wellness diaper). Interesting that these two diapers gave you a trail of fluff. You must be working out very strenuously indeed. In cool weather I have used the Dry 24/7.
If forced to exercise while wearing a diaper with a cloth-like backing, I have found the Seni Quatro and Seni Super Plus to do better than most other breathables (of course, I have not tried them all).
I routinely double tape all diapers used for exercise.
PUL pants should catch the fluff as well as normal leaks!
Again, compression pants enhance the efficiency of the diaper by keeping the diaper close to the skin, holding the leg gathers in place, reducing sag, and also reducing friction. There is no way any diaper fluff will get past my UnderArmour compression pants!!
This topic is of interest to many of us, so please keep providing comments about what works well and what does not.
--John