[Discussion] Belly band holsters?

I wear exclusively athletic pants, so traditional holsters seem out of the questions for me. How I currently carry is by wearing high-waisted spandex shorts under my pants and keeping my handgun (micro-compact) in the waistband of those, but I can't run well with that setup.

If you or someone you know have used a belly band holster, is there a brand you'd recommend? (Or suggest avoiding?)

Are they as practical as they seem?