By: Jesse - M.S. Health and Human Performance

A 2016 study from St. Andrews University in Scotland tested 13 typical beverages to find their impact on hydration over a four-hour period. 

 The results:

1: Skim milk

2: Oral rehydration solution (such as Pedialyte)

3: Full fat milk

4: Orange juice

5: Cola

6: Diet Cola

7:Cold tea

8: Tea

9: Sports drink (Powerade was used in the study)

10: Still water

11: Sparkling water

12: Lager (3.7 ABV)

13: Coffee

So what makes a drink hydrating?  Electrolytes, sugar (but not too much), and some calories.  Just drinking plain water often is devoid of electrolytes: such as sodium, potassium, magnesium, and chloride, which in turn dilutes the sodium-potassium pump. 

Does this mean that orange juice and diet Cola are healthier than plain water? The short answer is no.  However, when looking to maximally hydrate oneself during activity (such as bike riding), there are many better beverages besides plain water, and starting with a quality oral rehydration solution is a good place.