SODIUM INTAKE BEFORE, DURING AND AFTER EXERCISE.

I’m always talking with the athletes at The Journey 100 about sodium. I try to build their protocols, we run tests, I tell them “try water with salt,” and some of them look at me like it’s some kind of ancient ritual.

Well, it turns out we’re not that far from science.

I read the recent review by Alan J. McCubbin on sodium intake before, during, and after exercise, and I pulled out the most useful and practical points for me and my athletes. Here’s the essential part, explained simply—just the way you like it:

1. According to the research, there is no clear evidence that athletes need more sodium on a daily basis than the general population when looking at long-term balance; the body regulates losses through the kidneys and sweat. This breaks a myth that gets repeated all over social media: “I need to supplement sodium every day.” The article reviews population data and studies on athletes and concludes that a higher daily requirement is not proven in the absence of intense exercise.
2. Another important point is how sodium should be consumed and the importance of the sodium–fluid relationship. In simple terms: what matters for health and performance is how the sodium and the fluid you drink interact and affect extracellular osmolality. That influences thirst, fluid retention, and how fluids are distributed in the body. That’s why your sodium strategy should always be planned together with your fluid strategy.
3. Pre-exercise, sodium can help retain fluid or stimulate thirst if you start dehydrated, but the evidence is mixed depending on the dose and the form (food, solution, capsules). In other words: it can be useful if you start low on fluids and have time and resources to drink, but it’s not a universal recipe.
4. During exercise, there are many beliefs, but practical evidence is limited. Some studies look at sodium concentration in drinks and its effect on water or carbohydrate absorption, and overall there’s no strong evidence saying “this exact concentration is ideal” for everyone. What does appear clearly is that mismatches between sodium and water (for example, drinking a lot without sodium) can cause problems—from GI discomfort to risk of hyponatremia.
5. After exercise, sodium can help with rehydration, partly because it can increase voluntary fluid intake and improve retention of what you drink. However, the response varies between individuals and depends on what you already eat and drink during recovery.

In summary

The review shows that yes, sodium matters more than other electrolytes in several practical ways, but science still can’t give you a “magic number” for every runner. There are nuances, and individual variability is large.

Why this matters for us as runners (and why I prioritize sodium)

In long races, we typically see three common issues: nausea/GI distress, muscle cramping or “tightness” sensations, and rare but serious cases of hyponatremia. The review makes it clear that many of these problems don’t come from a total lack of sodium, but from imbalances between how much fluid you drink and how much sodium you consume.

Put simply: if you drink liters of water without adjusting sodium, you can dilute your plasma and increase your risk of problems. If instead you maintain a more consistent sodium–fluid relationship (and test it beforehand), you reduce those risks significantly.

What NOT to do: common mistakes I see (and the review also criticizes)

• Don’t jump on the “daily sodium supplement” trend without a reason. The author shows that at rest and outside of exercise, many athletes already consume more sodium than they think through their normal diet.

• Don’t try new strategies on race day. The study emphasizes the need for testing and rehearsal.

The practical side: how I translate this for my athletes

1. Evaluate your starting point
   Notice if you start long sessions feeling thirsty, with very concentrated urine, or with a sense of heaviness early on. If so, review how you’re hydrating in the hours before. The study suggests pre-exercise sodium can help if you start dehydrated, but it’s not necessary for everyone.
2. Train the sodium + fluid combination
   During long runs, test adding a sodium source (sports drink, homemade salted drink, capsules, or salty foods) in the same session where you control how much fluid you drink. The goal is that the drink feels good and doesn’t cause GI issues. If the drink tastes bad, reduce the concentration or change the format. The review shows palatability matters, and very salty drinks can reduce intake.
3. During exercise, avoid “drinking blindly”
   If you drink a lot of fluid and little sodium, you risk diluting plasma; if you sweat a lot and don’t replace sodium, you increase the risk of discomfort. Adjust sodium intake to your perception and to how much fluid you’re actually consuming.
4. After the session, include sodium as part of full recovery
   Don’t think only about a “sports drink.” Many common foods (soups, broths, bread, some processed foods in moderation) provide sodium and help rehydration. The review shows that after exercise, sodium can increase voluntary fluid intake and improve retention—but again, with individual variability.
5. Always have a Plan B
   If you experience nausea or discomfort during training, dilute the drink, slow down intake, and prioritize small sips. Use mild salty foods if drinks don’t sit well. The study emphasizes individual variability: what works for someone else might not work for you.

How we apply this at The Journey 100

With our athletes, we approach this methodically:

• Sweat testing to estimate fluid and sodium losses

• Testing pre-intake, drinks, and foods during long runs

• Tracking fluid intake per hour, sodium intake, and carbohydrate intake

• Adjusting based on athlete feedback until we find the comfort and performance sweet spot

All of this aligns with what the review recommends: use evidence to design and test, not to follow rigid formulas.

Important limitations

• The evidence does not allow for a universal sodium number per hour/day

• There is high individual variability (age, sex, sweat rate, sweat composition)

• There are research gaps regarding sodium forms (NaCl vs citrate) and taste effects on intake

• The study calls for more research and replication in diverse populations

Everything I’m sharing here is meant to reduce risk—not to replace medical evaluation if your situation is more complex.

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If you want to read the original paper:
McCubbin AJ. Sodium intake for athletes before, during and after exercise: review and recommendations. Performance Nutrition, 2025.

And if you want to take this into a personalized plan and test it in real simulations with your pace and terrain, you know where to find me: at The Journey 100, we help you test, adjust, and refine your fueling just like the pros—tailored to you.

Leer este artículo en Español: Leí la review reciente de Alan J. McCubbin sobre INGESTA DE SODIO ANTES, DURANTE Y DESPUES DEL EJERCICIO.