I hope this link idea works... https://www.meetanostomate.org/discussion-forum/viewtopic.php?t=9460&highlight=
If it did scroll, to my last post and you will see a hernia support belt. This is the style I thought I would get via the Oz government supply but then I discovered that no belt with a hole in it is endorsed in Oz as they risk a hernia developing through the hole.
So I got an endorsed belt that is 21 cm wide and 100 cm long. It locks with velcro. When positioned over the stoma the belt almost covers the whole of the bag. I mean just the tap pokes out from under the belt. When I asked the Stoma Nurse how does the stoma manage to output when it is firmly covered by a broad belt she said, it just does. She was right of course.
I have been wearing this belt for 2 weeks (because I have a slight parastomal hernia) and nothing has changed in my daily functions. When it comes to bag draining time I roll up the belt maybe 5 cm expose the bag more fully.
The reason I am talking about a hernia belt is I think it would give you 100% support for any active sport. No bag flopping about. Coraline has the same idea.