Hammer Gel, Water, and Osmolality

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Hammer Gel, Water, and Osmolality

Postby mandohack » Fri Feb 15, 2013 7:47 am

The latest Athlete Education Series (AES 1.13) recommends mixing water with Hammer Gel in a Hammer Flask to reduce waste by not using single serving Gel packs.

How does mixing Hammer Gel, particularly smaller servings, with water affect the osmolality of the solution? According to Solutions for Endurance Performance (, "Osmolality is determined by the concentration of specific dissolved substance per unit of fluid."

I'd imagine one serving of Gel with the rest of the flask filled with water having a negative impact on absorption of the Gel due to a significant reduction in Gel concentration. On the other end, five servings of Gel without water would be too concentrated?

Thank you,
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Re: Hammer Gel, Water, and Osmolality

Postby steve-born » Mon Feb 18, 2013 10:34 am

Hello Ian -

The main purpose of mixing a little water in with Hammer Gel in the flask is simply to lower the viscosity of the mix... some athletes don't care for the Hammer Gel's thickness so they can mix some water in there to make it a little less thick.

That said, you're still going to need to drink more fluid to maintain adequate hydration status and ensure efficient digestion of Hammer Gel (by maintaining the balance of fuel and fluid). Our general recommendation is 20-25 ounces/hour, plus or minus 3-4 ounces on either end (the amount will be dependent on a number of factors).

As you alluded to, this is even more important when you consuming Hammer Gel "as is"/undiluted; you definitely need to make sure you're drinking an appropriate amount of fluid to maintain optimal osmolality of 280 - 303 mOsm.

I hope I've answered your question!

Sincerely -

Steve Born
Fueling Expert
Event Sponsorship Coordinator
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Re: Hammer Gel, Water, and Osmolality

Postby mandohack » Mon Feb 18, 2013 6:22 pm

Thanks, Steve, that helps.
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