During-effort fuel · electrolyte · reviewed 26 Aug 2026
Nuun Sport 37
The most widely available tablet here, with all four electrolytes present, but at $2.50 per 1000mg of sodium it's among the most expensive ways to that dose in this set.
Score breakdown
The overall score is the average of what's below, each measured against every other electrolyte we've reviewed.
37
Mixed
Sodium dose ?Sodium per serving, on a scale topping out at 1000 mg — a single dose covering the top of what's typically lost to sweat in an hour.30
Value (cost/1000mg Na) ?What it costs to get 1000 mg of sodium from this product. Not physiological -- a market-based scale from $3.00 (0) to $1.00 (100).25
Potassium ?Potassium per serving, on a scale topping out at 200 mg — roughly the upper end of typical hourly sweat loss.75
Calcium ?Calcium per serving. Weaker grounding than sodium/potassium -- sweat calcium loss is minor and not really a primary target during exercise; the 100 mg ceiling is this catalog's practical high end, not a physiological one.13
Magnesium ?Magnesium per serving, on a scale topping out at 60 mg, roughly matching cited hourly sweat-loss ranges.42
Cost per 1000mg sodium
$2.50/1000mg
Sodium per tablet
300mg
Comparison
5 of 11 electrolytes heldPrices per single sachet at the cheapest box size we track. Best in green, worst in red, across the gels shown.
| Measure | Nuun Nuun Sport | LMNT LMNT Citrus Salt | Precision Fuel & Hydration Precision Fuel & Hydration PH 1000 | Science in Sport SiS GO Hydro | 4Endurance 4Endurance Electrolytes |
|
|---|---|---|---|---|---|---|
| SodiumThe main electrolyte lost in sweat, and the biggest single driver of cramping and hyponatremia risk. | 300 mg | 1000 mg | 500 mg | 345 mg | 250 mg | |
| PotassiumWorks alongside sodium in muscle and nerve function. | 150 mg | 200 mg | 130 mg | 65 mg | 70 mg | |
| CalciumInvolved in muscle contraction; lost in far smaller amounts than sodium. | 13 mg | 0 mg | 20 mg | 102 mg | 10 mg | |
| MagnesiumSupports muscle and nerve function; some evidence it blunts cramping. | 25 mg | 60 mg | 10 mg | 8.1 mg | 50 mg | |
| CarbohydrateMinimal by design. This is a hydration product, not a fuel source. | 4 g | 0 g | 3 g | 0.9 g | 0 g | |
| Price per tabletWhat one tablet costs. | $0.75 | $1.50 | $1.20 | $0.75 | $0.27 | |
| Cost per 1000mg sodiumThe only price that compares across different sodium concentrations. | $2.50 | $1.50 | $2.40 | $2.17 | $1.08 |
Verdict
what it does · what it costsWhat it does well
- All four electrolytes declared: sodium, potassium, calcium, and magnesium.
- Widely stocked at retail, easy to find in stores rather than online-only.
- 4 g of carbohydrate provides a small amount of fuel alongside hydration.
What it costs you
- 300 mg of sodium is the lowest of the effervescent tablets here.
- $2.50 per 1000mg of sodium, among the most expensive ways to that dose in this set.
- 15 kcal and 4 g carbohydrate mean it isn't a zero-calorie option if that matters to you.
Where to buy
Prices and links as last checked.
Who this is for
the numbers, appliedThe field tells you what it is. This is who should act on it.
Worth the money if
- You want the most widely available option on a store shelf.
- You want a complete four-electrolyte profile without hunting for it.
Look elsewhere if
- You want the lowest cost per 1000mg of sodium.
- You want a zero-carbohydrate, zero-calorie product.