Confluence Running · Nutrition education
Build a fluid plan from your conditions and training experience. Add sodium deliberately and keep it separate from carbohydrate.
Evidence → explanation → your plan
Fluid replaces water losses. Sodium contributes to electrolyte replacement. Drinking more than you need risks low blood sodium, even when you take salt. Your plan needs individual fluid decisions, not a universal tablet schedule.
Read the evidence ↗Drink to thirst or use a plan established during similar training. Fluid needs vary with weather, effort, clothing, and the athlete. Avoid forcing fluid beyond your needs. Sodium supplements do not prevent exercise-associated hyponatremia if you continue overdrinking.
Use comparable pre- and post-session body mass, measured with dry minimal clothing, plus fluid consumed and any urine produced. A one-kilogram mass change is approximately one liter of water for this practical estimate.
Example: 70.0 kg before, 69.5 kg after, 0.5 L drunk, no urine, one hour. Estimated sweat loss = 1.0 L per hour. Your drinking plan still depends on thirst, tolerance, conditions, and access. Avoid gaining body mass from excessive drinking.
Use the sodium line on each label. Drinks, gels, food, and capsules all contribute. Sweat sodium varies, so a universal number of tablets per hour does not fit everyone. A qualified practitioner helps interpret sweat testing and medical considerations.
| Illustrative intake | Calculation | Sodium |
|---|---|---|
| 0.5 L of a drink containing 600 mg sodium per liter | 0.5 × 600 | 300 mg |
| One food serving labeled 100 mg sodium | 1 × 100 | 100 mg |
| Combined example for that hour | 300 + 100 | 400 mg total |
This is arithmetic, not a recommended sodium target. Do not confuse milligrams of salt, total electrolytes, or tablet weight with milligrams of sodium.
nuun, ZYM, Hüma Hydration, Tailwind Rapid Hydration, SaltStick, and Salis belong in a hydration discussion. They do not replace a carbohydrate plan. Tailwind Endurance Fuel and Maurten Drink Mix provide substantial carbohydrate as well. Read the selected product rather than treating every drink powder as equivalent.
Confusion, collapse, or severe illness during or after an event needs immediate medical attention. Do not assume the cause is dehydration and keep forcing water. If you have kidney or heart disease, take medicines affecting fluid balance, or follow a sodium restriction, arrange your plan with your clinician.
nuun | Sport | Single TubeCheck the selected flavor, serving size, caffeine, ingredients, and live availability.
Salt Stick | Caps | Buffered Electrolyte Salts | 30 CapsulesCheck the selected flavor, serving size, caffeine, ingredients, and live availability.
Tailwind Nutrition | Rapid Hydration | Single Serving PacketCheck the selected flavor, serving size, caffeine, ingredients, and live availability.
Sweat-rate estimates describe water loss. They do not measure sweat sodium concentration. A salty shirt alone does not establish a precise sodium prescription. Record drink volume, sodium from every product, conditions, and your response.
Do not use salt to justify drinking beyond your needs. A product claim about extended release or cramp prevention does not establish individual dosing or independent race-performance benefit.
Source: Wilderness Medical Society. Exercise-associated hyponatremia guideline, 2019 update, published 2020.
