Should You Increase Sodium the Night Before a Race? Here’s What Experts Say
Endurance athletes have been leaning on salt tablets and electrolyte powders for decades to stay hydrated when it matters most. That's because electrolytes, especially sodium, help your body absorb and retain fluid, which becomes critical when you’re sweating for hours on end. Research shows sodium can boost short-term fluid retention and support endurance performance, particularly in hot, humid conditions where dehydration risk climbs quickly.
Lately, ultra-salty hydration mixes like LMNT and Saltt have taken that concept mainstream, with some athletes swearing by them as a race-day secret weapon. That surge in popularity brings up an important question: Do you actually need to increase your sodium intake the night before a race to perform your best?
"Typically, no, there is no need for any dramatic sodium intakes the night before a race," says Zach Tacy, trainer and endurance coach at Life Time Walnut Creek in California. "As with meals, the two to three days before are the most important."
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The longer the race, the more crucial it is to pay attention to how you’re fueling in the days leading up. Increasing sodium intake is generally most useful for events that last over two hours, or races done in hot or humid weather conditions. In such situations, extra sodium helps the body retain fluid and can lower the risk of cramping.
"I typically increase my electrolyte intake leading up to a race by adding electrolyte packets to every three to four water bottles during the day," Tacy says. "I will also make sure to do this a couple [of] hours prior to a race, or the morning of."
On extra hot race days, Tacy suggests increasing electrolyte intake during the event with rehydration packets or salt tabs.
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