In reply to DaveHK:
If you want a running vest style, then check the UD Adventure Vest. It's 16L, I've got the Mountain Vest, which is the size down at 12L and it's excellent, including easy to use bungees on the front that hold poles, one either side. Loads of pockets, and comes with 2 soft flasks
https://ultimatedirection.com/adventure-vest-4-0/
You might find a version 3 at a decent discount, and plenty reviews that explain the small differences