You know that moment during a workout when a muscle suddenly contracts and forces you to stop immediately? Muscle cramps are one of the most common complaints among athletes, whether beginners or experienced. The good news is that they are often preventable. And electrolytes are at the heart of the solution.
What exactly is a muscle cramp?
A cramp is an involuntary, sudden, and painful contraction of a muscle or group of muscles. It can last from a few seconds to several minutes and most often occurs in the calves, thighs, feet, or abdominals.
During exercise, cramps generally have two main causes: neuromuscular fatigue (the nerves controlling the muscles go haywire) and electrolyte imbalance. These two mechanisms are linked and worsen each other when you are not well hydrated.
The central role of electrolytes in muscle contraction
What electrolytes are
Electrolytes are electrically charged minerals: sodium, potassium, magnesium, calcium, and chloride. They circulate in the blood and inside cells, regulating an impressive number of biological functions, including muscle contraction.
Every time a muscle contracts, it is an exchange of sodium and potassium between the inside and outside of the muscle cell that triggers the contraction. When this balance is disturbed by sweating or insufficient hydration, muscles become unpredictable.
Potassium: the anti-cramp mineral
Potassium is probably the electrolyte most directly linked to muscle cramps. It regulates the polarization of muscle cell membranes. A potassium deficiency (hypokalemia) quickly results in cramps, muscle weakness, and palpitations.
Athletes who sweat a lot can lose between 200 and 600 mg of potassium per hour. Bananas are known for their potassium, but with only 370 mg per 100 g, they do not always compensate for losses during an intense session.
Magnesium: the muscle tension reliever
Magnesium is essential for muscle relaxation. After contraction, it allows the muscle to relax. Without sufficient magnesium, the muscle remains tense, promoting spasms and cramps.
Magnesium is involved in more than 300 enzymatic reactions in the human body, including energy production (ATP). Its deficiency is very common among athletes, especially those practicing endurance sports.
Sodium: the guardian of hydration
Sodium regulates water distribution in cells. It is also the main electrolyte lost in sweat (up to 1,000 mg per liter of sweat depending on intensity and heat). Without enough sodium, the water you drink does not stay in the cells and does not fulfill its hydrating role.
That’s why drinking only water during a long effort can paradoxically worsen cramps: you dilute the remaining electrolytes without replenishing them.
When do cramps most often occur?
Electrolyte-related cramps most often occur in specific situations: at the end of a long session (marathon, trail, 90-minute match), in hot and humid weather when sweating is heavy, after a sudden change in intensity or training volume, or when the diet is low in minerals.
A dehydration of only 2% of body weight is enough to significantly increase the risk of cramps and reduce athletic performance. This is a very small margin that many athletes exceed without realizing it.
How to prevent cramps with electrolytes?
Before exercise: stock up
Start hydrating well before putting on your shoes. In the 2 to 3 hours before an intense session, drink 400 to 600 ml of water. If the session lasts more than 60 minutes or it’s hot, add a source of electrolytes: enriched water, a hydration drink, or a powder supplement.
During exercise: don’t wait for thirst
Thirst is a late sign of dehydration. At this stage, electrolyte deficiency is already established. For efforts longer than 45 minutes, drink 150 to 200 ml every 15 to 20 minutes. For long sessions, favor a drink containing sodium, potassium, and magnesium rather than plain water alone.
After exercise: replenish reserves
Recovery starts right after the session ends. Drinking quickly helps replenish lost electrolytes and reduce nighttime cramps, which are common among athletes who do not hydrate enough after exercise.
The Buddy hydration drinks based on coconut water are specifically formulated for this recovery: they combine potassium (300 mg), magnesium (56 mg), and sodium (252 mg) in a ready-to-drink format, with no added sugar or artificial additives.
Electrolyte-rich foods to include daily
Beyond sports drinks, daily nutrition is the first line of defense against cramps. Here are the most interesting food sources for each key electrolyte:
For potassium: banana, avocado, sweet potato, spinach, coconut water. For magnesium: Brazil nuts, pumpkin seeds, dark chocolate, legumes, whole grains. For sodium: unrefined sea salt (in moderation), olives, aged cheeses.
A varied, plant-rich diet largely covers electrolyte needs at rest. But during and after exercise, losses through sweat require active compensation, especially in summer or during intense sessions.
FAQ: your questions about cramps and electrolytes
Why do I get cramps at night after sports?
Post-exercise nighttime cramps often indicate an uncorrected magnesium and potassium deficiency after the session. The body continues to eliminate electrolytes for several hours after exercise, and if reserves are not replenished, muscles contract uncontrollably at night. Good post-session hydration and a mineral-rich dinner significantly reduce this phenomenon.
Is drinking more water enough to prevent cramps?
No. Drinking only water during a long effort can even worsen electrolyte imbalances by diluting blood sodium. This is called exercise-associated hyponatremia. To effectively prevent cramps, you need to hydrate with a drink containing electrolytes, not just water.
How much magnesium should I take to avoid cramps?
The recommended daily intake of magnesium is 375 mg for an adult. Athletes may have slightly higher needs. In case of frequent cramps, supplementation of 200 to 300 mg per day (in the form of magnesium glycinate or citrate, which are better absorbed) can help, alongside hydration adapted to exercise.
Can cramps have causes other than electrolyte imbalance?
Yes. Muscle fatigue, neurological disorders, nerve compression, or certain medications can also cause cramps. If they are very frequent, intense, or occur at rest outside any sports context, it is advisable to consult a doctor.
Is there a difference between a cramp and muscle soreness?
Yes, completely. A cramp is an involuntary and sudden contraction, often during or just after exercise. Muscle soreness is a diffuse muscle pain that appears 24 to 48 hours after exercise, caused by micro-tears in muscle fibers. Both can be reduced by good hydration and electrolyte intake, but their mechanisms are different.
In summary
Muscle cramps are not inevitable for athletes. In most cases, they signal an electrolyte imbalance that can be prevented with a hydration strategy adapted before, during, and after exercise. Sodium, potassium, and magnesium are your best allies to keep your muscles in good shape, session after session.
