Electrolytes: when you actually need them

The electrolyte drink category is exploding. Liquid IV, LMNT, Element, Drip Drop, Nuun. Most ads suggest you need them daily. Most people don't. The exceptions are real.

What electrolytes actually are

The minerals in your body fluids that conduct electricity and regulate fluid balance:

• Sodium (Na+). The big one. Lost most via sweat.
• Chloride (Cl-). Comes with sodium.
• Potassium (K+). Intracellular; less lost via sweat.
• Magnesium (Mg2+). Small amounts; less critical for acute hydration.
• Calcium (Ca2+). Same.

For practical purposes, "electrolyte" supplementation usually means sodium with smaller amounts of potassium and magnesium.

When you actually need supplementation

1. Endurance exercise lasting over 60–90 minutes, especially in heat.

A typical adult sweats 0.5–2 L/hour during moderate-to-hard exercise. That sweat contains 200–700 mg sodium per liter. A 2-hour run in heat can lose 1–3 g of sodium.

Replacement during the activity: 300–700 mg sodium/hour, depending on sweat rate.

2. Working in extreme heat for hours.

Construction, agriculture, military, kitchens. Same physiology as endurance athletes.

3. Vomiting, diarrhea, or severe illness.

Acute fluid + electrolyte loss. Pedialyte or oral rehydration solutions are the right tool. (Adult versions exist; flavor preference aside, a child Pedialyte works for adults.)

4. Adapting to hot climate (early days only).

The body adapts to consistent heat exposure within 7–14 days, sweating less and conserving more sodium. During the adaptation period, electrolyte support helps.

5. The first 1–2 weeks of a low-carb / keto diet.

Carbohydrate restriction causes the kidneys to excrete more sodium and water. The "keto flu" is largely a sodium-and-electrolyte issue. 1–3g supplemental sodium/day during transition substantially reduces symptoms.

6. People taking diuretics.

Under medical guidance only.

When you almost certainly don't need them

• Daily moderate exercise (under 60 min)
• Office workers in air-conditioned environments
• Anyone eating a normal salt-containing diet and drinking when thirsty
• "Hangover prevention" (the evidence here is weak; mostly water and sleep)
• "Brain fog" / general wellness use

For these populations, your normal diet contains far more sodium than you need, and supplemental electrolytes are at best harmless and at worst contributing to hypertension over time.

The product landscape

LMNT. 1,000mg sodium, 200mg potassium, 60mg magnesium per packet. The "high-sodium" outlier; matches endurance athlete needs. Expensive ($1.50/packet).

Liquid IV. 500mg sodium, 380mg potassium per packet, plus added sugar (~12g). Marketed for general hydration; the sugar is real and uneeded for most use cases. Mid-priced.

Nuun. 360mg sodium, 100mg potassium, with mixed sweeteners. Marketed for endurance; mid-low sodium content makes it better for shorter sessions or general hot-weather use.

Drip Drop. 330mg sodium, 185mg potassium, 7g sugar. Originally formulated for medical rehydration (cholera, etc). Tastes the most like Pedialyte (which is the point).

Pedialyte (regular or pro). 245mg sodium, 180mg potassium, 6g sugar per 8oz. Designed for clinical use; works.

Salt + water + a squeeze of lemon. Free. Roughly 1g of salt = 400mg sodium. For most low-stakes electrolyte needs, this is the right answer.

DIY electrolyte drink

For endurance use:

• 16 oz water
• 1/4 tsp table salt (~575mg sodium)
• 1/4 tsp lite salt or potassium chloride (~300mg potassium)
• Juice of half a lemon
• 1 tbsp honey or maple (optional, for carb fueling)

Cost: ~$0.10. Effective.

The sodium-blood-pressure asterisk

Adding 1–3g of supplemental sodium during exercise is fine for healthy adults. The same dose daily for sedentary adults can elevate blood pressure in salt-sensitive individuals over time.

The right framing: extra sodium when you're losing it (exercise, heat, illness). Don't make it a daily habit if you're not losing it.

How to know your sweat sodium loss

If you're a serious endurance athlete, two options:

Sweat patches. Companies like Levelen and Precision Hydration offer mail-in sweat tests ($150–250). Tells you your specific sweat sodium concentration.

Self-experimentation. Add electrolytes to one long workout, skip them on another (similar conditions). If you feel notably better with them, you probably benefit; if no difference, your sodium losses are modest.

For most non-athletes, no testing is needed.

What to do during a typical workout

• Under 60 min, normal temps: water only
• 60–90 min, normal temps: water + small electrolyte boost
• 90+ min OR hot conditions: electrolytes (300–700mg sodium/hr) + carbs as needed

A reasonable household setup

For most people:

• A box of LMNT or similar for hot-weather days, long workouts, sick days
• A bottle of Pedialyte in the fridge for stomach bug days
• A salt shaker (which you already have)

Total cost: ~$30, lasts months.

Electrolytes are a tool. Tools used the wrong day cost more than they help.