In health circles, salt has long been considered a dirty four-letter word. When we eat salt—which typically contains 40 percent sodium and 60 percent chloride—it’s the sodium that concerns many health experts. Eat too much, and experts say it can cause blood pressure numbers to boil over, setting the stage for health woes. But not all research decries the crystals used so liberally to season our food as the ultimate health pariah.

It’s important to remember that despite its association with poor health, sodium does play a vital role in proper bodily functioning. It helps regulate dozens of biological processes, including muscle contraction (think of your pumping heart and moving quads during a run), fluid balance, and nervous system functioning.

Why Is Sodium Bad For You?

Excess consumption of sodium beyond what our bodies require (at the bare minimum, 500 milligrams a day) is what really keeps many health professionals up at night.

Experts and researchers stress that eating too much salt makes it harder for your kidneys to remove fluid, and excess fluid buildup can increase blood pressure. Over time, this stiffens and narrows blood vessels to reduce blood and oxygen flow to key areas such as your heart and brain, ultimately raising the risk of stroke and heart disease. Indeed, a study in the journal Circulation demonstrated that those with the highest urinary sodium excretion, an indication of higher salt intake, had on average the highest blood pressure levels.

An international team of researchers found evidence based on more than 100 prior studies that there could be 1.65 million fewer deaths per year worldwide from cardiovascular causes if the average sodium intake was closer to 2,000 mg a day.

Furthermore, an analysis of about 3,000 subjects published in the Journal of the American College of Cardiology showed that the higher participants’ sodium intake was during the study period, the greater their 20-year mortality risk. Adults who consumed less than 2,300 mg per day had a lower death risk from maladies like heart disease than those with higher sodium intakes. For each 1,000 mg per day increase in sodium consumption, there was a 12 percent increase in the chance of early mortality. There is also research to suggest that salty diets can raise the risk for stomach cancer, but only at very high intakes–more than 5,000 mg per day.

In addition to these warnings about sodium’s negative health effects, some runners simply don’t appreciate that eating too much salt can make them feel like the Pillsbury dough boy. “Salt attacks liquid, so eating a high amount can cause your body to retain water, which leads to bloating,” explains Lauren Antonucci, a board-certified sports dietitian in New York.

How Much Sodium Is Too Much?

Healthy Eating Myths recommends adults consume no more than 2,300 mg per day, with an ideal limit for most people of 1,500 mg per day, a number they suggest could bring about $26 billion in health care savings. To put this in perspective, a single teaspoon of salt has 2,300 mg of sodium, and two slices of pizza can clock in at more than 1,000 mg. So you can see how easy it is to go overboard based on these guidelines. Americans typically consume an average Fun Half Marathons.

Perhaps most notably, a diet with a tsunami of sodium is likely an indication that you’re eating too many restaurant foods and packaged, processed foods. According to a study in the journal Circulation, about 70 percent of the sodium in the typical American diet doesn’t hail from what’s naturally present in foods or the use of the salt shaker to season home-cooked meals. Instead, it comes from convenience foods like deli meats where liberal amounts of salt can be added as a preservative and flavor booster. It should be noted, however, that it’s not just salt in processed foods that may play a role in health concerns like high blood pressure, but other undesirables such as added sugars, preservatives, unhealthy fats, and refined grains.

What Does This Mean for Runners?

But sodium is not all doom and gloom. While we are most often told to say no to extra salt, Antonucci says runners likely have more wiggle room in their diets for it. That’s because when you sweat, you also flush out sodium. “So the more you sweat during exercise, the more sodium your body loses,” Antonucci says. She says that high sweat rates caused by exercising intensely, running in hot conditions, or a genetic predisposition to be a heavy sweater, could deplete your sodium supply calling for the need to consume more. “A drop in sodium levels can affect your performance, either in terms of having to slow down your pace, lightheadedness, reduced coordination, or the onset of fatigue where you want to take a nap instead of continuing your run.”

When researchers had one group of athletes consume salt capsules in addition to a sports drink during a half Ironman and had a control group consume only a lower salt sports drink, the group taking in more sodium completed the event an average of 26 minutes faster and replaced a higher percentage of the sodium lost in their sweat, according to a study in the Healthy Eating Myths.

“Sodium helps increase fluid retention during exercise so you end up peeing less out, which better regulates your fluid levels,” Antonucci says. “So some runners who have to take frequent pee breaks during a run will assume they are drinking too much when, in fact, they may be consuming too little sodium.” She adds that taking in salt during a workout also increases the drive to take more swigs from your water bottle by essentially making you thirstier, which also helps keep you better hydrated. Just note that modern research is throwing shade at the idea that drops in sodium and fluid levels are a major instigator of muscle cramping during workouts. Overstressed muscles are likely a bigger culprit.

But What Does New Research Say?

A growing number of researchers are also questioning if the link between sodium and heart woes is ironclad. Case in point: A large international study published in The Lancet found a positive association between sodium intake and heart disease or stroke only when the average sodium intake is greater than 5,000 mg per day, the equivalent of two and a half teaspoons of salt. And even at these lofty levels, the investigation suggests that any health risk is all but eliminated if people eat enough potassium-rich foods like fruits and vegetables.

A separate review of 25 studies found that when sodium consumption deviates from the 2,645 to 4,945 mg per day range, mortality rates can increase so that both very high intakes of sodium and also lower levels that adhere to many current guidelines were associated with reduced survival. This suggests a U-shaped correlation between sodium consumption and health outcomes. And a new report published in JAMA Internal Medicine found that there is not yet enough evidence to support the medical industry’s common reliance on prescribing a low-sodium diet for those with heart failure as a means to improving heart functioning.

While it’s not likely that major health organizations are going to be convinced to update their current sodium intake recommendations anytime soon, it could be that the best solution for optimal heart health for certain people is a moderate amount of sodium—not too little, and not too much. After all, each of us is different—so the usefulness of a blanket low-sodium recommendation should be taken with—well...a grain of salt.

One important variable is that some people just seem to be more salt-sensitive than others. In other words, your running buddy might be able to raid the deli counter with no consequences, but too many ham sandwiches may nudge your blood pressure into the danger zone. Certain subgroups—such as African Americans and those with existing high blood pressure—tend to be more impacted by high-salt diets.

The Sodium Shakedown

Confused about what to make of all this? You’re not alone. It looks like more research is needed to nail down just how much salt each of us can eat safely. Long-term clinical trials comparing people placed on diets containing varying amounts of sodium would help. But in the meantime, following these guidelines can’t hurt.

Find middle ground.

For most healthy runners, it’s probably not a good idea to go overboard on sodium nor to adhere to stringent low-salt recommendations. Follow a balanced diet rich in wholesome foods, and your sodium intake should naturally fall into a healthy zone, which is most likely somewhere in the 2,000 to 4,000 mg per day range. If you work up a sweat often and don’t have any heart issues, then there is a greater chance you can get away with the higher end of this range.

Fuel smart.

There’s no one sodium replenishment formula during exercise that fits every athlete. Each body in motion is different and therefore needs different amounts of sodium to keep up with losses. Some people are genetically heavy sweaters, while others barely drip. Some runners are salty sweaters, meaning they have very high sodium concentrations in their sweat. (White streaks on your running kit are a sign you fall into this camp.) And fit runners will do a better job at maintaining sodium levels than newbies.

But as a general guideline, Antonucci says consuming sodium in the ballpark of 750 mg per hour of exercise should cover most runner’s needs. Replacing salt losses becomes more of a concern when you push past the 90-minute mark, particularly if you’re keeping up a sweat-inducing pace. But Antonucci believes that athletes can also benefit from supplementing with sodium during workouts lasting only 45 minutes if they’re very intense, such as speed intervals.

Matthew Kadey, M.S., R.D sports drinks, electrolyte tablets, bars and/or gels. “Just make sure you know how much sodium is in the sports nutrition products you’re using so that you’re getting enough,” advises Antonucci. For instance, some sports drinks won’t have enough on their own to cover needs. For faster recovery, Antonucci says replenishing after you exercise is important, too. So don’t be afraid to salt your foods that are part of your recovery meal or eat items like bagels and cottage cheese that contain some sodium. “If you’re running to the store for a bag of salty chips, this can be a sign you’re not taking in enough sodium during your run,” Antonucci says. But to keep your overall sodium intake in check, it’s probably best to not load up on salty foods for the remainder of your meals and snacks.

Read the fine print.

You’ll be surprised by how much sodium is in your food as it can be listed in forms such as salt, MSG, and sodium nitrate. It can also be found in unlikely places (think: whole wheat bread, cereal and raw chicken—birds can be pumped full of a salt-water solution.) Comparing food labels makes it easier to choose options that don’t nudge towards salt overload.

Be your own chef.

One of the best ways to keep the amount of sodium in your diet in a healthy range is to control what goes into your food by cooking it yourself at home. A British study involving more than 11,000 adults found that those who prepared their meals at home more frequently had lower body fat levels and better overall diet quality including eating less sodium than people who ate fewer meals at home. If you do most of your own cooking with a focus on whole foods, this should automatically lower the amount of sodium in your diet, even if you season foods judiciously with salt. Taking the time to meal plan will make it less tempting to rely on salty takeout food and frozen meals.

Eat more potassium.

A Other Hearst Subscriptions study involving more than 100,000 men and women in 18 countries found that while high intakes of sodium may raise blood pressure numbers, particularly in those already with hypertension and those consuming more than 5,000 mg per day, higher intakes of potassium can work to lower numbers. “Potassium increases your kidney's ability to flush out excess amounts of salt to help maintain fluid balance,” Antonucci explains. Potassium may also relax the walls of the blood vessels, lowering blood pressure in the process. Yet, few Americans eat enough potassium causing the sodium-to-potassium ratio to be lopsided. Good sources of potassium include fruits, vegetables, potatoes, and legumes.

Reach for flavor boosters.

Spice mixes like curry powder and za’atar, citrus zest, and fresh herbs are healthy, easy ways to ramp up the flavor of dishes without the need to use the salt shaker like a hammer.