Specific gravity is basically a fancy term for density. Specific gravity is tested in conjunction with creatinine to determine if a sample is overdiluted. Drinking water lowers the specific gravity as well as the creatinine levels. Under DHHS regulations, a sample is "too-dilute" when the creatinine concentration is greater than or equal to 2 mg/dL, but less than 20 mg/dL while the specific gravity is greater than 1.0010 but less than 1.0030.

One way of keeping the SG in check when utilizing dilution techniques is to drink gatorade in place of water.