One theory is that the strong, acidic taste of pickle juice activates nerves in the mouth and throat. That signal may temporarily reduce the overactive nerve activity causing the muscle to cramp. In other words, the sour taste itself may help interrupt the cramping reflex.

That doesn’t mean pickle juice prevents every type of cramp. Muscle cramps can happen for many reasons, including fatigue, strenuous exercise, dehydration, certain medications, or underlying health problems.

Pickle juice also contains a lot of sodium, so drinking large quantities isn’t a great idea—especially for people who have been advised to limit salt because of blood pressure, kidney, or heart concerns.

For an occasional exercise-related cramp, a small amount may be worth trying alongside gentle stretching and normal hydration.

So it isn’t exactly an old wives’ tale. There is real research behind it—but pickle juice is better viewed as a possible quick cramp remedy, not a cure for every muscle cramp.