Electrolytes for Runners: Sodium per Hour and 8 Products Compared

Reviewed by Sarah Law, Dip CNM, Naturopathic Nutritionist

Published 1 November 2026. Every LMNT, Precision Fuel & Hydration, SaltStick, Nuun, Liquid I.V. and Tailwind figure on this page comes from the brand's own website or nutrition panel (read 29 October to 1 November 2026), with prices rechecked on 1 November 2026; our own prices were read live from our UK and US stores on 6 November 2026.

Ultimate Electrolytes: 500 mg sodium, 500 mg potassium and 150 mg magnesium per 500 ml serving, zero sugar, sweetened with stevia, six flavours including Unflavoured.

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Best electrolytes for runners: the comparison table

The table compares one serving of eight electrolyte products runners commonly use, as each brand tells you to take it. Every figure for the other brands was read from the brand's own product page or nutrition panel; prices are each brand's standard one-off price for its usual pack on its own store, before subscription discounts, checked between 29 October and 1 November 2026. Where a brand's UK store price could be read from our checks it is shown too.

Sources: drinklmnt.com, precisionhydration.com (PH 1000 per-litre panel halved for one tablet in 500 ml, as the brand directs; price from its US store), aletenutrition.com (SaltStick), nuunlife.com, liquid-iv.com and liquid-iv.co.uk, and tailwindnutrition.com (Mandarin panel), read 29 October to 1 November 2026 (references 18 to 23). Our figures are from our printed labels (Watermelon is a 4 g serving and Unflavoured 3.2 g, with the same mineral amounts) and our live store prices. We have not converted any currency. Price per serving is pack price divided by servings.

Two things the table does not show at a glance. First, the water. Per litre as mixed, by our arithmetic from each label, Liquid I.V. comes to about 1,060 mg of sodium, PH 1000 and ours to 1,000 mg, and Nuun Sport to about 630 mg. The ACSM position stand suggests drinks used during exercise carry roughly 20 to 30 mmol of sodium per litre, which is about 460 to 690 mg; the stronger mixes suit heavy or salty sweaters, or runners who drink less fluid.³ Second, the carbohydrate: only Tailwind is a fuel. Everything else, ours included, is for minerals and fluid, so on a marathon you would pair it with gels, chews or food.

Which electrolyte gives the most sodium for the money?

SaltStick capsules win on cost per milligram of sodium by a distance; most sachets and tablets cost about two to three times as much for the same sodium. The table below divides each price per serving by its sodium to give the cost of 1,000 mg, the amount in one LMNT stick or two servings of ours.

Our arithmetic from the prices in the first table, rounded to the nearest cent or penny. Tailwind's cost includes its carbohydrate, so it is not a like-for-like sodium price. No currency has been converted.

If sodium is all you want, a capsule is the cheapest way to get it. What a drink adds is the fluid itself, plus, in our case, the most potassium and magnesium per serving of anything in the table. Magnesium contributes to electrolyte balance and to normal muscle function, and potassium contributes to normal muscle function; both are authorised claims on the GB nutrition and health claims register.¹⁷ Sodium has no authorised claim of its own.

Do runners need electrolytes?

Not for every run. For a typical easy run of under an hour, sweat losses are small enough that water, and the salt in your normal meals, cover them. The ACSM's fluid position stand says drinks containing electrolytes and carbohydrates "can provide benefits over water alone under certain circumstances", and advises customised plans because sweat rates and sweat sodium vary so much between people.³ In practice, those circumstances are long runs, heat and humidity, and heavy sweating.

Carbohydrate amounts from the 2016 joint position statement of the ACSM, the Academy of Nutrition and Dietetics and Dietitians of Canada (ref 4); sodium per litre from the 2007 ACSM fluid position stand (ref 3). These are general starting points for healthy adults, not personal advice.

How much sodium do runners need per hour?

There is no single figure, because both sweat rate and sweat saltiness differ from runner to runner. The largest published dataset, 1,303 athletes tested by the Gatorade Sports Science Institute between 2000 and 2017, found endurance athletes sweated 1.28 litres an hour on average (plus or minus 0.57) and lost 51.7 mmol of sodium an hour (plus or minus 27.8).¹ At 23 mg per mmol, that is about 1,190 mg an hour on average, and roughly 550 to 1,830 mg an hour for the middle two thirds of athletes. Sweat testing methods themselves vary, and a 2017 review notes that intensity, heat, acclimatisation, body size and diet all shift the numbers.²

You do not have to replace every milligram during a run. What matters most is not drinking far more than you sweat, and taking some sodium in what you do drink on long efforts. To find your own starting point:

1. Weigh yourself with minimal clothing before and after a typical one-hour run at race effort, without a toilet stop in between.
2. Note what you drank. Weight lost (1 kg is about 1 litre) plus fluid drunk is your sweat rate for those conditions. The ACSM recommends keeping losses under about 2% of body weight.³
3. Look at your kit. White salt marks on a dark top or a gritty face after a long run suggest saltier sweat, and a stronger mix such as 1,000 mg of sodium per litre may suit you better.
4. Repeat in different weather, because a warm day can double what you lose.

"With runners, I start with a simple sweat check before choosing any product: weigh before and after a typical hour, note what you drank, and look for salt marks on your kit. That gives us a sensible starting point, and we adjust it on long runs rather than copying someone else's numbers."

Sarah Law, Naturopathic Nutritionist | Optimised Female

Salt tablets vs electrolyte drinks for runners

Salt capsules give sodium without fluid; electrolyte drinks give sodium in fluid. Capsules such as SaltStick (215 mg sodium, suggested one every 30 to 60 minutes of exercise) or Precision Fuel & Hydration's capsules (250 mg) suit runners who take plain water from aid stations or who do not like flavoured drinks. A drink mix suits training runs from your own bottle or vest, and is easier to dose with fluid you will actually drink.

The trade-off is control. With capsules it is easy to take sodium on a schedule while drinking very little, or the reverse. A study of 26 triathletes found that a salt supplement (113 mmol of sodium, taken before and during a half-ironman) left blood sodium higher and gave a faster total race time than a placebo, though it was a small single trial.¹⁰ In 161 km runners, by contrast, the rate of sodium taken in supplements made little difference to who developed low blood sodium: drinking too much did.⁷ Whichever you choose, sodium supports the fluid you drink; it does not replace drinking to thirst.

Should you take electrolytes before, during or after a run?

All three have a place on long or hot days. Before: the ACSM advises drinking slowly at least four hours before exercise (about 5 to 7 ml per kg of body weight), noting that sodium in a drink or a salty snack helps you keep that fluid.³ One serving of an electrolyte drink with breakfast before a long run does that job. During: on runs beyond 60 to 90 minutes, sip to thirst from a mix with sodium in it, and take carbohydrate alongside if you are running hard. After: replace what you lost with fluid plus sodium; a normal salted meal often does this on its own, and an electrolyte drink is a convenient bridge if the meal is a while away.

For a daily routine rather than race prep, see our guide on how to take electrolytes, and if you also take creatine, whether you can mix creatine and electrolytes in one drink.

Do electrolytes stop cramps when running?

Probably not, for most runners. The idea that cramps come from salt loss is popular, but the research in runners does not support it well. Among 161 km ultramarathon runners, 14.3% reported cramping and 26.8% near-cramping; weight change, use of sodium supplements, the rate of sodium intake and post-race blood sodium did not differ between those with and without cramps. What did differ was a prior history of cramping and higher blood creatine kinase, a marker of muscle damage.⁹

That points to muscular demand: running further or faster than your training supports. Pacing, specific long-run training and fuelling well are the levers with better evidence. Magnesium is often suggested too; we looked at the trials in best magnesium for leg cramps, which are mostly about night cramps rather than running. If cramps come with dizziness, confusion or vomiting, stop and get medical help.

Can runners drink too much water?

Yes, and on race day it is the more serious risk. Drinking far beyond sweat losses dilutes blood sodium, a condition called exercise-associated hyponatraemia. At the 2002 Boston Marathon, 13% of 488 finishers who gave blood had low sodium and 0.6% had critically low levels. It was linked to weight gain during the race, finish times over four hours and body-weight extremes; the type of fluid drunk was not a factor.⁶ In the 161 km Western States race, 6.6% of finishers tested had low blood sodium even though 93.9% used sodium supplements, and overhydration was the main feature of those affected.⁷

The 2015 international consensus statement on exercise-associated hyponatraemia names drinking beyond thirst as the main cause and advises using thirst to guide drinking.⁸ Sports Dietitians Australia's position on exercise in heat makes the same point from both sides: plan fluid to avoid significant under- or overconsumption.⁵ Electrolyte drinks do not make overdrinking safe; they are no substitute for drinking to thirst and checking your weight in training.

"For most of my clients running under an hour, water and their normal meals cover it. Where I do suggest an electrolyte drink is for long or hot sessions, and I always pair it with the advice to drink to thirst. More fluid is not better, and on race day that matters as much as what is in the bottle."

Sarah Law, Naturopathic Nutritionist | Optimised Female

Electrolytes for marathon runners: do not forget carbohydrate

For a marathon, carbohydrate matters more to performance than electrolytes. The 2016 joint position statement of the ACSM, the Academy of Nutrition and Dietetics and Dietitians of Canada recommends 30 to 60 g of carbohydrate an hour for exercise lasting one to two and a half hours, and up to 90 g an hour beyond that for athletes who have practised it.⁴ A zero-sugar electrolyte drink such as ours, LMNT or PH 1000 provides almost none of that, so you would add gels, chews or food. A carbohydrate-electrolyte drink like Tailwind does both jobs at once: three scoops an hour would give 75 g of carbohydrate and 930 mg of sodium by our arithmetic from its panel.

Under GB and EU rules, only carbohydrate-electrolyte drinks that meet set conditions on energy, sodium and concentration may claim to help maintain endurance performance during prolonged exercise; a mineral-only drink such as ours does not meet them and we make no such claim. Practise your race-day drink and fuel on long runs, never on the day itself. If you are building a training block, our guide to creatine for runners covers the other supplement runners ask us about most.

How much sodium, potassium and magnesium do you need a day?

One serving of our powder sits well inside both countries' guidance. The UK and the US frame reference intakes differently, so we show both, each under its own name.

Sources: NHS salt and other vitamins and minerals pages; UK NRVs from retained Regulation (EU) 1169/2011, Annex XIII; NIH Office of Dietary Supplements potassium and magnesium fact sheets; FDA sodium guidance (references 11 to 16). Runners who sweat heavily lose more sodium than sedentary adults, which is why sports bodies give separate advice on sodium during long exercise, apart from everyday salt targets; if you have been told to limit salt, ask your doctor first.

How we test Ultimate Electrolytes

Our labels carry a code that links to independent lab results. For lot 33447931 (Orange and Lime), Certified Group in Tustin, California, an ISO/IEC 17025:2017 accredited laboratory, measured the following per 5 g serving (report 25-660895):

Lead is below the 3.0 mg/kg maximum for food supplements in retained Regulation (EC) 1881/2006. Scan the code on the tub to see the lab results for your batch; more on our methods on our testing procedures page.

Where Love Life Supplements is not the best choice

• If you want the most sodium per serving, LMNT has 1,000 mg against our 500 mg.
• If you want the cheapest sodium, salt capsules such as SaltStick cost about half as much per milligram.
• If you want fuel and electrolytes in one bottle, a carbohydrate drink such as Tailwind is built for that; ours has no carbohydrate.
• If you want single-serve sticks or tablets for a race belt, LMNT, Nuun, Liquid I.V. and PH 1000 come in sachets or tubes; ours is a tub with a scoop.
• If your runs are under an hour in cool weather, you may not need any of these products.

For more side-by-side comparisons, see LMNT vs Liquid I.V. vs Ultimate Electrolytes and our best sugar-free electrolyte powder guide.

Who should check with a doctor before using electrolytes?

Most healthy adults can use an electrolyte drink around long runs. Check with your doctor or pharmacist first if you have been told to cut down on salt, have high blood pressure, kidney or heart problems, or take medicines that affect potassium or fluid balance, such as some blood pressure tablets (ACE inhibitors, ARBs), potassium-sparing diuretics or other diuretics. The NIH notes that supplemental magnesium above 350 mg a day can cause loose stools; one serving of ours provides 150 mg.¹⁴ Ask a healthcare professional before starting any supplement if you are pregnant or breastfeeding.

Frequently asked questions

About the Reviewer: Sarah Law, Dip CNM

Sarah Law is a Certified Naturopathic Nutritionist and Functional Practitioner specialising in hormonal health, gut health, and evidence-based nutrition. She holds a Diploma in Naturopathic Nutrition from the College of Naturopathic Medicine (CNM, London) and is a Certified Functional Health Coach. Sarah combines naturopathic principles with modern functional nutrition science to help her clients make informed health decisions.

Learn more about Sarah.

About the Author: Ben Law

Ben Law is the founder of Love Life Supplements and host of the Optimised Health Show. He is a qualified Advanced Dietary Supplement Advisor and Primal Blueprint Certified Expert, and has spent 14 years building transparent, research-led formulations manufactured to GMP and BRC standards. He wrote this guide from the published sweat, hydration and endurance-nutrition research, the ACSM and consensus position statements, NHS and NIH guidance, each brand's own product pages and nutrition panels, and our own label and lab data.

LMNT, Precision Fuel & Hydration, SaltStick, Nuun, Liquid I.V. and Tailwind are trademarks of their respective owners and are not affiliated with Love Life Supplements. Learn more about Ben.