Despite conventional wisdom, actual research on coffee, iced coffee, and its derivatives as a workout drink may just surprise you

Photo by Valeriia Miller/Unsplash

Last week, as the calendar moved from August to September and the autumn season started looming over the northern hemisphere, the Washington State Department of Natural Resources tweeted something funny:

I'm begging you all to remember that a venti PSL isn't adequate hydration on the trail.
— Washington State Dept. of Natural Resources (@waDNR) August 30, 2022

There’s some justification (but not the entire truth) to this hilarious warning. Coffee is well-known as a diuretic, which means it’s a substance that causes you to pee a lot. It was thought that urinating a lot would leave you dehydrated, especially in the hot weather, which can actually kill you if you’re doing some physical activity outdoors like hiking.

So the conventional wisdom was that if you’re exercising or doing anything physical, just drink water. Maybe a sports drink if you’re going more than a little harder. If you’re going to have coffee, take it before your workout for the caffeine boost to your physical and mental performance, not as a water replacement.

That’s what we all thought, though. Coffee fans would be pleasantly surprised to find out that it’s totally okay to chug down coffee during your workout. A study from 2014 showed that coffee does not dehydrate you—in fact, it gets you all fine and hydrated as any water-based drink would, on top of energizing you for whatever you’re about to do. Another study from a few years ago corroborates that it isn’t caffeine that could dehydrate you.

It’s even better as a post-workout drink, as all the iced coffee you’re sipping can replenish all the water you’ve sweated out during the session. Taking in all that coffee is a much easier way to drink a lot of your daily water requirement.

If anything, the actual downside to drinking a lot of iced coffee is that most drinks pack a lot of sugar. The calories from a super sweet and tall cup of iced coffee can completely wreck your diet. Just be careful with that—unless you’re not really watching your weight for sports performance then by all means, chug down that venti during your workout.