If you are holding some water in your abdominal region and you have a contest/show the following day, last minute tip, get some Preparation H, rub it all over the abdominals, obliques, and lower back, sit in a tanning bed, and watch the water come right out. When your tanning session is done you'll see a puddle of water on your stomach. That should get that last bit of water out from below the epidermal layer. Good luck!

Dani