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Drinking GoodSport

3 min read time


Do Alcohol and Caffeine Affect Hydration?

Two frequently asked questions we hear related to hydration are, “What is the relationship between alcohol and hydration?” and, “What is the relationship between caffeine and hydration?” At GoodSport, we keep an eye on all of the latest research related to proper hydration and best hydration strategies. Learn more about the relationships between alcohol and hydration and caffeine and hydration below. 

Alcohol is dehydrating.

Alcoholic beverages have a diuretic effect, meaning alcohol increases fluid loss via increased production of urine.  Increased fluid loss via urination increases the time required to completely rehydrate and can be problematic particularly when the time to fully rehydrate is short.  Alcohol consumption appears to be less detrimental when there are 24 hours or more available to rehydrate. However, binge drinking of large volumes of alcohol is always problematic for hydration status.  Alcohol is also a central nervous system depressant and will impair physical and cognitive performance, so avoiding it when training or competing is advised.

Reasonable amounts of caffeine will not dehydrate you.

Most caffeinated beverages do not contain enough caffeine to impede rehydration after exercise or during the day, especially when consumed with foods containing sodium and other electrolytes.

Caffeine has a mild diuretic effect in caffeine-naive or caffeine-starved people. Those who ingest caffeine on a regular basis are less likely to experience caffeine-induced diuresis. Also, it is unusual for people to consume large amounts of caffeine without also consuming food, which offsets the diuretic impact of caffeine. Exceptions to this generalization include ingesting multiple energy drinks or energy shots in the absence of food intake. Bottom line:  research indicates that when caffeine consumption is less than 250 - 300 mg/day, the diuretic impact of caffeine is negligible.

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