The Honest Answer
The FDA's 2,300 mg daily ceiling was written for sedentary adults eating heavily processed food in air-conditioned environments. It was never meant for athletes, low-carb eaters, or anyone sweating in heat. If you're any of those, your real number is meaningfully higher.
Your Sodium Needs by Profile
| Profile | Daily sodium target |
|---|---|
| Sedentary adult | 2,300 mg |
| Active adult (3-5 workouts/week) | 3,000-3,500 mg |
| Athlete (daily training) | 4,000-5,000 mg |
| Low-carb / Keto eater | +1,000 mg above baseline |
| Hot climate / heavy sweater | +500-1,500 mg |
| Endurance event (marathon, triathlon) | 5,000-7,000 mg on race day |
Why Athletes Under-Replace
Sweat sodium concentration ranges from 200 to 2,000 mg per liter. The average is about 950 mg per liter. That means a typical hour of training in moderate conditions can drain 500-1,000 mg of sodium — and most "everyday" hydration products give you 80-250 mg per serving.
The math doesn't work. You can't replace an hour of sweat with a Gatorade and expect to feel sharp the next day.
Why Keto Needs Extra
When you cut carbs, insulin stays low. Low insulin means your kidneys stop reabsorbing as much sodium. You pee it out. The symptoms — headache, fatigue, irritability, brain fog — are universally called "keto flu" but it's almost entirely a sodium-and-potassium deficit. Add 1,000 mg of sodium per day and most keto flu disappears in 24-48 hours.
Where Smart People Get It Wrong
Most adults look at the 2,300 mg number and try to eat low-sodium foods. They end up tired, foggy, and craving salty snacks. The fix isn't avoiding salt — it's getting most of it from real food (salted nuts, broth, olives, real cheese) and using a high-sodium hydration mix to cover training and heat.
Calculate your real sodium target → Shop 300mg-sodium electrolyte sticks →