Sodium Significantly Impacts Your Body’s Hydration Levels—Here’s How, According to an RD

Staying properly hydrated is hugely a important part of feeling your best and ensuring your body functions properly. Drinking plenty of water is a great way to ensure you stay sufficiently hydrated, but have you ever chugged a ton of water only to feel more thirsty? The reason for that is often due to sodium.

“Sodium is a mineral that our body needs for [proper] fluid balance, muscle function, and nerve function,” shares Breanna Cecil, MS, RDN, LN, a board-certified registered dietitian nutritionist that specializes in working with athletes. “Sodium also helps transport nutrients into our cells, like amino acids and vitamins, and controls the amount of water that goes in and out of cells.” It can be naturally found in various foods, but is also often consumed as sodium chloride (aka table salt)—whether by way of food processing or when added as a seasoning.

The relationship between sodium and our body’s hydration levels can be pretty confusing. After all, one minute you may have been told to be mindful of your sodium consumption to avoid dehydration, the next, TikTok videos suggesting you add salt to smoothies for hydration are flooding your For You Page and that one friend who swears by chugging pickle juice after a long run is messing with your head. What’s most important to keep in mind, says Cecil, is that what our bodies needs to rehydrate can vary, depending on the situation. Sometimes, you may need a glass of water, while other times, you may need an electrolyte like sodium to replenish lost fluids.

In an effort to make matters less confusing, we asked Cecil to further unpack how sodium impacts hydration in the body, including how to know when you need more of it—and when to dial back.

How sodium impacts hydration levels

The ultimate detail to remember when thinking about hydration is that your body needs both water and sodium for proper fluid balance, so having more or less of either can impact your hydration levels. In most cases, Cecil affirms your overall consumption of sodium can affect how often you need to rehydrate with beverages containing sodium. However, it’s still important to properly rehydrate if you’re constantly active or an athlete. According to Cecil, the 2020-2025 Dietary Guidelines for Americans recommend that individuals intake less than 2,300 mg or less than a teaspoon of sodium per day.

“Most individuals in the general population need less than 2,300 mg of sodium per day, [but] sodium needs are higher for active individuals and athletes,” says Cecil. “[When] we sweat, the main electrolyte lost is sodium, so when athletes are continually losing sodium through their sweat while at practice or games, they need to replenish what they lost.” She adds that not adding sodium through either snacks or a hydration powder can increase the chances of muscle cramps along with other unfavorable effects. “When a person is just one percent dehydrated, there is a decrease in cognitive functioning. At just a two percent dehydration, you can see a physical drop in performance, especially for athletes,” says Cecil.

“Most individuals in the general population need less than 2,300 mg of sodium per day, [but] sodium needs are higher for active individuals and athletes,” says Cecil.

If you’re unsure as to whether or not your body needs sodium to hydrate, Cecil suggests paying attention to symptoms associated with hyponatremia—a condition when your sodium levels are too low and often caused by taking in too much fluid without sufficient sodium. She adds, “in early stages of hyponatremia, there can be symptoms of nausea, headache, cramps or just feeling more tired than usual. When there is a more serious case of hyponatremia, it can lead to seizures and loss of consciousness. ”

So what are ways to combat this to ensure you properly rehydrate when sweating more than usual? “I always tell my clients to listen to their bodies, because they know themselves best. If you think back on your day and notice you have had little sodium intake through your diet, maybe an electrolyte powder or beverage may be beneficial,” says Cecil. She also suggests having salty snacks, such as trail mix, or incorporating a hydration powder such as Liquid IV.

“The American College of Sports Medicine (ACSM) recommends a sodium intake of 300 to 600 mg/hour of prolonged exercise,” Cecil says. Most individuals generally get more than enough sodium through their diet, but Cecil advises highly active folks and athletes to increase their sodium levels at an amount specific to them, their diet, the climate, and their sweat rate. Before increasing or reducing the amount of sodium in your diet, be sure to talk with your doctor, as every individual is different.

Most individuals generally get more than enough sodium through their diet, but Cecil advises highly active folks and athletes to increase their sodium levels at an amount specific to them, their diet, the climate, and their sweat rate.

Is too much sodium always bad for you?

Consuming too much sodium has been linked to high blood pressure, heart disease, and stroke, so it’s very important to be mindful of your overall consumption. “If someone who has hypertension consumes too much sodium, [this] can cause a negative effect by increasing blood pressure and therefore decreasing the flow of blood and oxygen to your heart,” Cecil says. “When it comes to people that sweat in excess or athletes, they may need a higher amount of sodium due to the losses in their sweat.”

Again, Cecil underscores that too much sodium impacts everyone differently.

3 tips for hydrating properly

If water isn’t doing the job of quenching your thirst, then Cecil shares three ways to help you properly rehydrate—especially after sweating a ton.

Consider incorporating some salty snacks: “Salty snacks, such as trail mix or pretzels, are beneficial not just for the sodium, but the carbohydrates facilitate sodium and water absorption,” Cecil says.

Electrolyte beverages that include sodium: One tip Cecil shares in navigating the electrolyte aisle is to look at the label to ensure it includes the necessary components for hydration. “If you look at the label, [ensure] there are minimal amounts of sodium, which is the main electrolyte we lose in our sweat,” she says.

Add salt to coconut water: Despite the common belief that coconut water is great for hydration, Cecil points out how that’s not the case. “Coconut water has a great amount of potassium but lacks the amount of sodium needed to rehydrate you, especially if you are an athlete.” She advises adding salt, such as Celtic sea salt, to it to compensate for the lack of sodium if coconut water is your favorite hydration beverage.

The bottom line? Sodium plays a vital role in maintaining proper fluid balance, especially in the case of excessive sweat loss due to physical activity or hot temperatures. If you’ve had a salty snack and are feeling parched, drinking water to balance your hydration may be beneficial. On the other hand, if water alone isn’t doing the trick, you may need a salty snack or an electrolyte beverage to rehydrate properly.