Pickle juice has suddenly become the “supplement” of the autumn. Before the Chicago Marathon on 11 October, McDonald's bottled the brine from its signature pickles in 2-ounce bottles (about 60 ml) under the name Pickle Boost and gave them away free for three days — two per person, to runners and spectators alike. Eight days earlier, on 3 October, at the run leg of IRONSTAR Sirius (a Russian triathlon series), the team of Russian coach Suren set up an anti-cramp station where brine with and without vinegar was handed out in random order — for their own study.

Where did the idea of drinking pickle juice for a cramp come from, and what do we actually know about it?

The key experiment: 49 seconds

Almost everything the “pickle juice” theory rests on was done by Kevin Miller's group (USA) in 2009–2015.

In the key study (Medicine & Science in Sports & Exercise, 2010), men were first dehydrated by about 3% of body mass, and then a cramp was induced in a foot muscle by electrically stimulating the nerve. Right after the cramp began, participants drank 1 ml per kg of body mass (on average 74 ml) of pickle juice or distilled water.

After water the cramp lasted 133.7 seconds, after pickle juice 84.6 seconds: 49 seconds (about 37%) shorter.
Plasma composition in the 5 minutes after the sip did not change in either group.

Hence the authors' main conclusion: pickle juice works not as a source of salt. It simply doesn't have time to be absorbed. It appears that the sour, salty taste triggers a reflex in the oropharynx that “switches off” the overexcited motor neurons of the cramping muscle.

The salt never reaches the blood: three checks and one caveat

60 minutes, no change. In 9 men at rest, 1 ml/kg of pickle juice did not shift plasma sodium, potassium, magnesium or osmolality (Journal of Athletic Training, 2009).
After two hours in the heat. Participants lost about 2 l of fluid and 97 mmol of sodium in sweat, drank about 79 ml of pickle juice (roughly 1.5 g of sodium) — and again nothing changed in the blood over an hour (2014).
Two doses during exercise. Even a double dose on a cycle ergometer in the heat produced neither extra sodium nor hyperkalaemia (2015).
The stomach “stalls”. If you drink a lot — 7 ml/kg, which for a 75 kg person is more than half a litre — pickle juice stops emptying from the stomach after just 5 minutes: the acidity and high osmolality get in the way (2010).

The last point matters on the course: a small sip is a tool, a large serving is a risk of a heavy stomach.

Vinegar or salt

This is exactly the question tested at IRONSTAR Sirius. The reflex hypothesis puts its money on acetic acid: in an analysis of products athletes use to treat cramps (Journal of Strength and Conditioning Research, 2020), notable amounts of acetic acid were found in pickle brines, yellow mustard and special “pickle shots”, but not in sports drinks. There is still no direct comparison of “brine with vinegar versus brine without vinegar” in people with cramps in the peer-reviewed literature — so a randomised aid station at a race may give a first signal, though it won't replace a peer-reviewed study.

What happens in the real world

In patients with cirrhosis — the only RCT on real cramps rather than electrically induced ones (American Journal of Gastroenterology, 2022). 82 patients drank a sip of pickle brine or water at the start of each cramp; over 28 days cramp severity on a 10-point scale fell by 2.25 points versus 0.36 with water. These are not athletes, and the dose here is a sip, not millilitres per kilogram.
In swimmers — a University of Stirling press release about a student project: 10 national-level swimmers, a crossover design, 10 ml of pickle juice per 10 kg of body mass. The work was circulated by a maker of pickle-juice drinks, and we found no peer-reviewed publication — treat it as a signal, not as evidence.

Who is actually at risk of cramping

A fresh systematic review by Brazilian authors (Muscle & Nerve, online since 3 September 2026) pooled 9 prospective studies and 11,274 participants and ran 36 meta-analyses of possible risk factors. Only three turned out to be significant:

A history of cramps — the odds of a recurrence are about 4.4 times higher (strong level of evidence).
Higher blood potassium and magnesium after the race (moderate and limited level) — in other words, not a “deficiency”, rather the opposite.

By contrast, age, weight and height are not associated with cramps, and no consistent association was found with hydration, sodium, training volume or pace either.

This fits well with pickle juice: if a cramp is a neuromuscular glitch rather than a salt deficit, then what helps is a reflex, not topping up electrolytes. More on the “it cramped, so you lacked salt” myth in a separate article.

How to apply this

The dose is a sip, not a bottle. In cramp experiments and safety checks it is about 1 ml per kg: 60–80 ml for an adult. A Pickle Boost bottle is exactly that size.
It's first aid, not prevention. There is no evidence for drinking pickle juice in advance “so you don't cramp”. It works at the moment a cramp has started or is about to.
First, ease off and stretch the muscle. Stretching the cramping muscle remains the first move; pickle juice may speed up the release.
Test your stomach in training. A sour, salty shot at kilometre 35 is not the best time to try it for the first time.
If your cramps keep coming back — that is the strongest risk factor. Plan ahead: at the first signs, slow down, stretch the muscle and take a sip. The race planner will help you work out a realistic race pace.
Hypertension and kidney disease. A shot contains about 1–1.5 g of sodium. As a one-off that's not much, but if you are on a salt restriction, check with your doctor. Mustard is not a salt-free alternative: in the 2014 study its portion was matched for sodium.

The bottom line

In a lab experiment, a sip of pickle juice (1 ml/kg) shortened a cramp by 49 seconds — to 84.6 versus 133.7 with water.
Nothing changes in the blood in the hour after pickle juice: the mechanism is a reflex from the oropharynx, not salt replacement.
A fresh meta-analysis (11,274 participants): the main predictor of cramps is a history of cramps (×4.4), not dehydration; potassium and magnesium in those who cramped were, if anything, higher rather than lower.
Vinegar versus salt is an open question; on 3 October coach Suren's team tested it at IRONSTAR, and there are no results yet.

Sources: Miller K.C. et al. “Reflex inhibition of electrically induced muscle cramps in hypohydrated humans”. Med Sci Sports Exerc, 2010;42(5):953–961. DOI: 10.1249/MSS.0b013e3181c0647e · Miller K.C. et al. J Athl Train, 2009;44(5):454–461. DOI: 10.4085/1062-6050-44.5.454 · Miller K.C. J Athl Train, 2014;49(3):360–367. DOI: 10.4085/1062-6050-49.2.23 · McKenney M.A. et al. J Athl Train, 2015;50(2):141–146. DOI: 10.4085/1062-6050-50.2.07 · Miller K.C. et al. “Gastric emptying after pickle-juice ingestion”. J Athl Train, 2010;45(6):601–608. DOI: 10.4085/1062-6050-45.6.601 · Hooper Marosek S.E. et al. J Strength Cond Res, 2020;34(6):1539–1546. DOI: 10.1519/JSC.0000000000003595 · Tapper E.B. et al. “The PICCLES Randomized Controlled Trial”. Am J Gastroenterol, 2022;117(6):895–901. DOI: 10.14309/ajg.0000000000001781 · Costa L.D.S. et al. “Risk Factors for Exercise-Associated Muscle Cramps: A Systematic Review With Meta-Analysis”. Muscle Nerve, 2026;74(5):1375–1386. DOI: 10.1002/mus.70389