Short answer: if you cramp during hard exercise, the evidence for magnesium is thin and the evidence for pickle juice is more interesting. A 2020 Cochrane review found magnesium supplements are unlikely to meaningfully reduce cramps, and there are no trials at all in exercise-associated cramp. Pickle juice, on the other hand, has a proper mechanism behind it: a fast neural reflex triggered by the sour brine hitting the back of your throat. They are not really competing on the same pitch.
Every cramp-prone athlete has been told the same thing: take magnesium. It is the default advice, repeated so often that nobody questions it. But when you actually dig into the science, the magnesium story gets shaky fast, and a 50ml shot of sour pineapple pickle brine starts to look a lot smarter. Here is the honest head to head.
Does magnesium actually stop muscle cramps?
This is the awkward bit. In 2020, the Cochrane Collaboration, which is about as gold-standard as evidence reviews get, looked at every decent randomised trial on magnesium for cramps. Their conclusion for older adults with regular idiopathic cramps was blunt: magnesium is "unlikely" to provide any clinically meaningful benefit, with barely any difference between magnesium and a placebo (Garrison et al., 2020).
And for exercise-associated cramps, the kind you get at mile 20 or deep in the third set? They found zero randomised controlled trials. None. The entire "take magnesium for cramp" industry, as it applies to athletes, is built on an evidence base that does not exist yet. The same review also noted that oral magnesium gives roughly 11 to 37 percent of people gut trouble, think diarrhoea and nausea, which is the last thing you want on race morning.
None of this means magnesium is useless. It is an essential mineral and you absolutely need enough of it. Under UK and EU rules, the one authorised claim is clear and worth stating properly: magnesium contributes to normal muscle function. That is a real, approved statement about the nutrient. It is just not the same thing as a proven cramp cure, and the Cochrane data is the reason for the gap.
Why do athletes get cramp in the first place?
For decades the story was dehydration and lost electrolytes. Sweat buckets, lose salt, cramp up. Simple. Except it does not hold up. The problem is that this old model never explained why cramp usually hits one specific muscle you have been hammering, rather than your whole sweaty body at once.
The better-supported explanation is the altered neuromuscular control theory, first properly laid out by Schwellnus and colleagues (1997). The idea is that when a muscle fatigues, the balance between the excitatory and inhibitory signals feeding your motor neurons goes haywire. The excitatory drive ramps up, the inhibitory brake fades, and the muscle locks into that involuntary, screaming contraction. Cramp is a nervous system fault, not a plumbing problem. That single shift in understanding is why the whole "just replace electrolytes" approach keeps letting people down, and it is exactly where pickle juice comes in.
How does pickle juice work differently to magnesium?
Here is the clever part. If cramp is a neural misfire, you fix it at the nerve, not the muscle. And that is what the brine appears to do.
The landmark study is Miller et al. (2010), published in Medicine & Science in Sports & Exercise. Researchers electrically induced cramp in dehydrated volunteers, then gave them either water or pickle juice. Water did basically nothing. Pickle juice cut cramp duration to about 85 seconds, roughly 37 percent faster than water, and crucially it worked within about a minute and a half, far too quickly for anything to have been absorbed and reached the muscle. The relief came before the fluid had even left the stomach.
The researchers concluded it was a "neurally mediated reflex". The sharp, sour hit of acetic acid on receptors in your mouth and throat fires a signal that appears to reset the overexcited nerves and quiet the cramp. Magnesium, a slow-absorbing mineral you swallow and wait on, is playing a completely different, and much slower, game.
Pickle juice vs magnesium for cramps: the head to head
Line them up and it is not close on the mechanism front:
- Speed: Pickle juice acts via a throat reflex in one to two minutes (Miller et al., 2010). Magnesium supplements take days to weeks to shift blood levels.
- Evidence in athletes: Pickle juice has a specific, published mechanism in exercise cramp. Magnesium has no randomised trials in exercise-associated cramp at all (Garrison et al., 2020).
- Targets the actual cause: Pickle juice hits the nervous system, which is where the fault sits. Magnesium targets muscle biochemistry, which the neuromuscular model says is not the trigger.
- Gut comfort mid-effort: A 50ml shot is easy. Loading magnesium risks the exact stomach upset you cannot afford on race day.
To be fair to magnesium, it plays a genuine role in your baseline nutrition, and being deficient in anything is bad news for performance. But as an acute answer to a cramp that has just seized your calf, the reflex mechanism is the one with the science behind it.
What is actually in the PickleUp Pro Cramp Shot?
The PickleUp Pro Cramp Shot is built around that acetic acid mechanism rather than the electrolyte myth. Each 50ml pineapple shot contains 1,411mg of acetic acid, the active sour compound behind the reflex, alongside 363mg of sodium and 21.4g of fast carbohydrates for working muscles. It also delivers 31.5mg of magnesium, and, as noted, magnesium contributes to normal muscle function. It is the sharp, no-faff format that athletes reach for courtside, mid-marathon and on the bike, precisely because you can neck it in seconds when it matters.
Want the full mechanism explained from the ground up? Read our pillar guide, Pickle Juice for Cramps, or go straight to the PickleUp Pro Cramp Shot.
Frequently asked questions
Is pickle juice better than magnesium for cramps?
They work differently. Magnesium is a slow-absorbing mineral with, per the 2020 Cochrane review, little proven benefit for cramps and no trials in exercise cramp. Pickle juice works through a fast throat reflex shown to shorten cramp duration in Miller et al. (2010). For acute, exercise-driven cramp, the reflex mechanism has the stronger evidence.
Can I take magnesium and use pickle juice together?
Yes. They are not mutually exclusive. Magnesium is an essential mineral that contributes to normal muscle function as part of a balanced diet, while a pickle juice shot is an acute, in-the-moment tool athletes use during hard sessions. Many people keep their magnesium intake sensible and reach for a shot when cramp threatens.
How fast does pickle juice work compared to magnesium?
Fast. In Miller et al. (2010), cramp relief came in around 85 seconds, well before the fluid could be digested, pointing to a neural reflex. Magnesium supplements, by contrast, take days to weeks to change your blood levels, so they are a background strategy, not an emergency one.
Why does the sour taste matter?
Because the current science says the relief is triggered in the mouth and throat, not the muscle. The strong acetic acid hit is thought to stimulate sensory receptors that fire a reflex to calm the overexcited motor neurons behind the cramp. No sour kick, no reflex, which is why a bland electrolyte drink does not do the same job.
References
- Miller, K.C., Mack, G.W., Knight, K.L., et al. (2010). Reflex inhibition of electrically induced muscle cramps in hypohydrated humans. Medicine & Science in Sports & Exercise, 42(5), 953-961.
- Garrison, S.R., Korownyk, C.S., Kolber, M.R., et al. (2020). Magnesium for skeletal muscle cramps. Cochrane Database of Systematic Reviews, Issue 9, CD009402.
- Schwellnus, M.P., Derman, E.W., Noakes, T.D. (1997). Aetiology of skeletal muscle cramps during exercise: a novel hypothesis. Journal of Sports Sciences, 15(3), 277-285.
- Johnston, C.S., Kim, C.M., Buller, A.J. (2004). Vinegar improves insulin sensitivity to a high-carbohydrate meal in subjects with insulin resistance or type 2 diabetes. Diabetes Care, 27(1), 281-282.
