A 2002 study, compared water, coconut water, and standard sports beverages to determine which beverage was best for post-exercise hydration. The eight subjects exercised in the heat and then were rehydrated with either water, coconut water, or a sports drink. Researchers found that there was no difference in sodium levels, urine output, or fluid balance between the three beverages, meaning all three beverages were equally hydrating, but there was significantly less nausea or fullness with the coconut water allowing the participants to drink more of the beverage.