Most wrestlers know the basics about how to be hydrated for the skinfold certification.
Drink lots of water, monitor urine color, and avoid caffeine. Unfortunately this may not be enough to guarantee a wrestler has fully re-hydrated from hard workouts. Guzzle a large bottle of fluids and then go hours before drinking again. This floods the body with fluids and turns on the kidneys to filter out the excess water. The athlete goes to the bathroom about 60-90 minutes later.