The short version
Capsules give you dose control; tablets give you sodium with the fluid. A capsule lets you add sodium without changing what is in your bottle, which matters when you are drinking plain water or eating real food. A dissolving tablet puts sodium into the drink, which is easier to keep track of and gentler on a stomach that is already unhappy. Neither is a substitute for knowing roughly what you lose, and sodium needs vary enormously between people.
Common questions
How much sodium do I actually need?
It varies hugely between individuals and with heat, and published sweat sodium concentrations span a wide range. Generic per-hour numbers are a starting point, not a prescription. Work out your own through long training runs in similar conditions, and if you have high blood pressure, kidney disease, or take medication affecting fluid balance, ask a doctor before loading sodium.
What are the signs I am getting this wrong?
Persistent nausea, a sloshing stomach, swollen fingers, headache and confusion late in a race are all worth taking seriously. Hyponatremia is a medical emergency and it looks like ordinary late-race misery until it does not. Get medical help rather than pushing through.
Can I just eat salty food?
Yes, and plenty of ultrarunners do. Broth, crisps, pickle juice and salted potatoes at aid stations are doing the same job with better palatability. The advantage of capsules and tablets is that you can carry them and know the dose.
At a glance
| SaltStick Electrolyte Capsules, 100 count | Nuun Sport Electrolyte Tablets, 4 pack | |
|---|---|---|
| Taken with | Any fluid | Dissolved in the bottle |
| Dose control | Precise, per capsule | Per bottle |
| Changes the taste of your water | No | Yes |
| Carries calories | No | Very few |
| Stomach tolerance | Can be harsh dry | Generally easier |
| Works with real food fuelling | Well | Less flexibly |
Choose the SaltStick Electrolyte Capsules, 100 count if…
You fuel with real food or plain water and want to add sodium separately. Capsules let you take more in heat and less when it is cool, without committing an entire bottle to a flavour you may not want at hour nine. Take them with fluid rather than dry, because a capsule sitting in an empty stomach is a good way to feel sick.
Check SaltStick Electrolyte Capsules, 100 count on Amazon
Choose the Nuun Sport Electrolyte Tablets, 4 pack if…
You want the simplest system and your stomach is the limiting factor. A tablet in the bottle means sodium arrives with every sip, which is easier to keep consistent than remembering capsules on a schedule. It also makes water more palatable in heat, which matters when the problem is that you have stopped wanting to drink.
Check Nuun Sport Electrolyte Tablets, 4 pack on Amazon
Related
Comparison based on published manufacturer specifications and the general consensus of owner reports. We have not tested these products side by side. Confirm current specifications and prices before buying. As an Amazon Associate we earn from qualifying purchases, at no extra cost to you.