Do bananas help with leg cramps?

Probably not, and nobody has put the banana itself to the test. A 2026 meta-analysis of 13 randomized or quasi-randomized trials of electrolyte supplements for cramps and muscle pain found that potassium, the mineral bananas are famous for, lacked supportive evidence. We found no randomized trial and no systematic review of bananas for cramps. The one study that fed bananas to men after exercise, 9 of them after an hour of cycling in the heat, found plasma potassium an hour later at 4.6 mmol/L after two servings, against 4.4 with none. Its authors concluded bananas are unlikely to relieve exercise cramps that way, and cramps themselves were not measured.

Myth. The story goes that cramps come from running low on potassium and a banana tops it up. Both halves have been looked at. Potassium supplements lacked supportive evidence across randomized trials. In ultra-distance runners, those who cramped had no clinically significant difference in blood electrolytes from those who did not. A banana may still be a fine snack. As a cramp remedy it has no evidence behind it.

What the trials found

There is no trial of bananas for cramps to report. What exists is evidence around the edges of the question, and it all points the same way.

The banana study that measured potassium

Nine healthy men without a history of exercise cramps cycled for an hour in the heat and then ate no banana, one serving or two, on separate days. An hour after eating, plasma potassium was only slightly higher than with no banana and stayed in the normal range. The rise in potassium and glucose came too slowly to treat a cramp that starts during exercise, the authors wrote, especially one that develops near the end of a race. The abstract does not say the order of the three days was randomized, which is part of why this is weak evidence.

Potassium and other electrolytes as supplements

The 2026 meta-analysis pooled 13 randomized or quasi-randomized trials of magnesium, sodium, calcium and potassium for cramps or muscle pain, published between 1995 and August 2025. Calcium and potassium lacked supportive evidence. Sodium-based solutions did reduce cramp susceptibility, in exercise and in liver cirrhosis. These were supplements, and the abstract does not say how many of the 13 trials tested potassium.

Magnesium, the banana's other mineral

A 2020 Cochrane review found that magnesium did not reduce idiopathic leg cramps in people who were mostly older adults, presumed to have night cramps. Across 5 trials with 307 people the difference was 0.18 fewer cramps a week, with a confidence interval from 0.84 fewer to 0.49 more, on moderate-certainty evidence. The same review found no randomized trial at all of magnesium for cramps that come on during exercise. That is the exact situation in which bananas are most often recommended. Our magnesium and cramps review covers this in more detail.

Do cramping runners actually run low on electrolytes

In a prospective cohort at an ultra-distance road race, researchers compared 21 runners who had acute exercise cramps with 22 who did not. They found no clinically significant differences in serum electrolytes and no difference in hydration. This is observational and potassium was not reported separately in the abstract, but it removes some of the premise behind eating a banana for cramps.

Bananas as fuel

Bananas do work as a carbohydrate source. In a randomized crossover trial of 14 trained cyclists, eating bananas during a 75 km time trial gave similar performance and blood glucose to a 6 percent carbohydrate drink. Cramps were not an outcome of that trial, so it says nothing about them.

Who should be careful

Not for everyone. According to the NIH Office of Dietary Supplements, people with chronic kidney disease, or taking ACE inhibitors or potassium-sparing diuretics, can develop high blood potassium even from food intakes below the adequate intake. ACE inhibitors and angiotensin receptor blockers reduce how much potassium the kidneys excrete, and the fact sheet advises monitoring potassium in people taking them. If that is you, how many bananas fit your diet is a question for the person treating you.

Banana is an infrequent cause of anaphylaxis. A 2023 case report describes one patient whose reaction was linked to eating banana and exercising, and notes it had previously been reported in only one other patient. It is rare, and it matters here because bananas are usually eaten around exercise.

What expert bodies say

We found no statement from a body on our trusted list about bananas and cramps. The NIH Office of Dietary Supplements potassium fact sheet speaks to safety, quoted above, and not to cramps. A family medicine clinical inquiry on magnesium for cramps was left out because it is a secondary source that overlaps the Cochrane review.

How we searched

What would change this answer

• A randomized trial of bananas in people who actually get cramps, with cramps as the outcome. None exists, and none is registered on ClinicalTrials.gov.
• A peer-reviewed version of the cramp-threshold study of bananas, which we could find only as an unpublished thesis.
• Trials of potassium specifically for exercise cramps. The 2026 meta-analysis does not say in its abstract how many potassium trials it had, so the negative finding may rest on very few.

For what a banana does provide, see the banana page. For how much potassium you need and where else to get it, see the potassium guide.

Sources

1. ev-bmc-01 · Observational data · crossover feeding study (randomization not stated in abstract) · n = 9
   The effect of banana ingestion on EAMCs is unknown; however, these data suggested bananas are unlikely to relieve EAMCs by increasing extracellular [K(+)] or [glucose](p).
   
   Who: nine euhydrated men without exercise-associated muscle cramps, 0 g, 150 g or 11 oz (300 g) of bananas after 60 minutes of cycling in the heat
   Effect: plasma K+ at 60 min: 4.6 (2 servings) vs 4.5 (1 serving) vs 4.4 mmol/L (0 servings), P < .05; within normal clinical values; cramp outcome not studied
   Certainty: The only direct study of banana; cramps were not measured, participants not prone to cramps; randomization is not named in the abstract, hence C.
   J Athl Train, 2012, Plasma potassium concentration and content changes after banana ingestion in exercised men · checked 2026-10-06 · we read the abstract
2. ev-bmc-02 · Observational data · crossover feeding study (randomization not stated in abstract) · n = 9
   The changes in [K(+)](p), plasma K(+) content, and [glucose](p) do not occur quickly enough to treat acute EAMCs, especially if they develop near the end of competition.
   
   Who: nine euhydrated men, blood sampled 3 to 60 minutes after eating 0, 1 or 2 servings of banana
   Effect: K+ content rose only at 30 and 60 min after 2 servings (+4.4% and +5.8%)
   Certainty: The conclusion on speed is from plasma dynamics, not from cramps.
   J Athl Train, 2012, Plasma potassium concentration and content changes after banana ingestion in exercised men · checked 2026-10-06 · we read the abstract
3. ev-bmc-03 · Meta-analysis or systematic review · systematic review and meta-analysis of randomized trials · n = 13 trials
   Sodium-based solutions reduced cramp susceptibility in exercise and cirrhosis, while calcium and potassium lacked supportive evidence.
   
   Who: randomized or quasi-randomized trials of magnesium, sodium, calcium or potassium supplementation for cramps or myalgia, 1995 to August 2025
   Effect: calcium and potassium lacked supportive evidence; sodium-based solutions reduced cramp susceptibility in exercise and cirrhosis
   Certainty: Supplements, not food; the number of potassium RCTs is not named in the abstract.
   Int Dent J, 2026 · checked 2026-10-06 · we read the abstract
4. ev-bmc-04 · Meta-analysis or systematic review · Cochrane systematic review and meta-analysis of RCTs · n = 307
   This includes the primary endpoint, percentage change from baseline in the number of cramps per week at four weeks (mean difference (MD) -9.59%, 95% confidence interval (CI) -23.14% to 3.97%; 3 studies, 177 participants; moderate-certainty evidence); and the difference in the number of cramps per week at four weeks (MD -0.18 cramps/week, 95% CI -0.84 to 0.49; 5 studies, 307 participants; moderate-certainty evidence).
   
   Who: people with idiopathic cramps, largely older adults (mean age 61.6 to 69.3 years) presumed to have nocturnal leg cramps
   Effect: MD -0.18 cramps/week (95% CI -0.84 to 0.49) at four weeks; moderate-certainty evidence
   Certainty: We carry over only as no effect even from a supplement.
   Cochrane Database Syst Rev, 2020 · checked 2026-10-06 · we read the abstract
5. ev-bmc-05 · Meta-analysis or systematic review · Cochrane systematic review · n = 11 trials, 735 participants
   We found no RCTs evaluating magnesium for exercise-associated muscle cramps or disease-state-associated muscle cramps (for example amyotrophic lateral sclerosis/motor neuron disease)
   
   Who: RCTs of magnesium supplementation for skeletal muscle cramps, searched to September 2019
   Effect: 0 RCTs for exercise-associated muscle cramps
   Certainty: A gap precisely where banana is most often recommended.
   Cochrane Database Syst Rev, 2020 · checked 2026-10-06 · we read the abstract
6. ev-bmc-06 · Observational data · prospective cohort study · n = 43 of 72 followed
   There are no clinically significant alterations in serum electrolyte concentrations and there is no alteration in hydration status in runners with EAMC participating in an ultra-distance race.
   
   Who: runners in an ultra-distance road race, 21 with acute exercise-associated muscle cramping and 22 controls
   Effect: no clinically significant electrolyte or hydration differences; post-race sodium 139.8 vs 142.3 mmol/L
   Certainty: Potassium is not singled out in the results; observational.
   Br J Sports Med, 2004 · checked 2026-10-06 · we read the abstract
7. ev-bmc-07 · Randomized controlled trial(s) · randomized crossover trial · n = 14
   BAN and CHO ingestion during 75-km cycling resulted in similar performance, blood glucose, inflammation, oxidative stress, and innate immune levels.
   
   Who: trained cyclists, bananas or 6% carbohydrate drink at 0.2 g/kg carbohydrate every 15 minutes during 75-km cycling
   Effect: time 2.41 vs 2.36 h, P = 0.258; similar blood glucose
   Certainty: About fuel, not cramps.
   PLoS One, 2012 · checked 2026-10-06 · we read the abstract
8. ev-bmc-08 · Position of an expert body · government fact sheet · n = —
   However, in people with impaired urinary potassium excretion due to chronic kidney disease or the use of certain medications, such as angiotensin converting enzyme (ACE) inhibitors or potassium-sparing diuretics, even dietary potassium intakes below the AI can cause hyperkalemia [11].
   
   Who: people with impaired urinary potassium excretion
   Effect: no UL for potassium in healthy people; hyperkalemia risk with CKD, ACE inhibitors, potassium-sparing diuretics
   Certainty: For an ordinary person a banana is safe; caution applies to risk groups.
   NIH Office of Dietary Supplements, Potassium Fact Sheet for Health Professionals · checked 2026-10-06 · we read the section
9. ev-bmc-09 · Position of an expert body · government fact sheet · n = —
   These medications reduce urinary potassium excretion, which can lead to hyperkalemia.
   
   Who: people taking ACE inhibitors or ARBs, especially with impaired kidney function
   Effect: reduced urinary potassium excretion; risk of hyperkalemia
   NIH Office of Dietary Supplements, Potassium Fact Sheet for Health Professionals · checked 2026-10-06 · we read the section
10. ev-bmc-10 · Laboratory or animal data · case report · n = 1
    Banana is an infrequent cause of anaphylaxis, which has been previously reported in combination with postprandial exercise in only 1 patient.
    
    Who: one patient with probable preprandial food-dependent exercise-induced anaphylaxis to banana
    Effect: anaphylaxis after banana plus exercise; previously reported with postprandial exercise in only 1 patient
    Certainty: Rare; relevant because banana is advised precisely during exercise.
    Asia Pac Allergy, 2023 · checked 2026-10-06 · we read the abstract