April 29, 2026, 8:59 am | Read time: 5 minutes
Magnesium is one of the most important minerals we consume through food. Athletes, in particular, should ensure they get enough. But when should it be taken–before or after a workout? FITBOOK consulted nutrition experts and diabetologist Dr. Matthias Riedl on this topic.
How Much Magnesium Do You Need Daily?
Magnesium is not only crucial for muscles, the nervous system, and energy metabolism, but it also ensures strong bones and teeth. Those who experience a lot of stress, engage in intense sports, or frequently consume alcohol, which leads to dehydration, need sufficient magnesium.
To stay healthy, the German Nutrition Society (DGE) recommends that adult men consume 350 milligrams of magnesium daily. Adult women need about 300 milligrams.1 To achieve these levels, the DGE suggests frequently consuming the following foods2:
Legumes such as beans, peas, and lentils, green leafy vegetables, as well as fish and seafood, are also good sources of magnesium. Even dark chocolate with a high cocoa content is recommended in this regard and is preferable to milk chocolate. However, if these foods are rarely on your menu, you might be deficient in this mineral. Only a blood test by your doctor can confirm if this is the case.
These symptoms can also indicate a magnesium deficiency:
- Persistent fatigue
- Frequent muscle cramps and twitches (e.g., in the calves)
- Digestive issues
- Restlessness
- Heart palpitations
- Headaches
- Irritability
Also interesting: Magnesium L-Threonate–a natural performance booster?
When to Take Magnesium
According to Dr. Matthias Riedl, the exact time of day–morning or evening, before or after exercise–is not crucial for magnesium intake. “Evening hours are recommended, as this can prevent possible nighttime muscle cramps,” the expert notes. Taking magnesium supplements in the evening or after exercise optimally supports muscle recovery and promotes good sleep.
Exception: In endurance sports, supplementation during the activity is advisable, as magnesium loss through sweat is increased, says the expert.
Who Should Consider Magnesium Supplements?
Those who rarely consume magnesium-rich foods or have an increased need (such as due to frequent exercise) can supplement with magnesium. However, it should not be overdone, as an overdose can lead to unwanted effects like diarrhea and gastrointestinal issues, according to the Consumer Center.3 Therefore, the additional daily dose of 250 milligrams of magnesium recommended by the Federal Institute for Risk Assessment should not be exceeded. Higher-dosed supplements are discouraged unless prescribed by a doctor due to a deficiency.
“Magnesium supplementation can be beneficial for athletes, as their needs increase by ten to twenty percent compared to rest,” explains Dr. Riedl. According to the expert, supplementing over several weeks can improve physical performance, such as jumping ability.
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Magnesium–Capsules or Effervescent Tablets?
When choosing a supplement, there are several factors to consider, as Dr. Riedl explains: “It is more sensible to opt for capsules instead of effervescent tablets, as the latter often contain many additives. These could be glycerol, sweeteners, or citric acid. Capsules, on the other hand, contain only pure magnesium.”
The type of magnesium compound is also important. The body can better absorb organic compounds like magnesium citrate or so-called chelate through the mucous membrane. Cheaper magnesium supplements are often made from inferior inorganic magnesium salts like magnesium carbonate or magnesium oxide, which our intestines cannot absorb as well.
What Else Is Important When Taking Magnesium?
It is crucial to take it regularly and daily over a longer period. Therefore, it is best to develop a routine. “It is recommended to supplement magnesium for several weeks to fully realize its effects,” says the diabetologist.
For example, a study with 130 migraine patients found that taking a magnesium supplement reduced the frequency of migraines.4 During the three-month intake period, participants reported fewer migraine days than before. Another study with 46 older patients with sleep problems showed that taking 500 milligrams of magnesium daily for eight weeks improved their sleep quality.5
Take Magnesium with a Meal
To avoid digestive issues like diarrhea and to better tolerate magnesium, it is recommended to take it with a meal.6 “If you tend to feel nauseous, the magnesium supplement should not be taken on an empty stomach but with a meal,” explains the nutrition expert.
Whether to take magnesium before or after exercise also depends on whether you prefer to train on an empty stomach. In the first case, consuming magnesium can quickly lead to digestive problems during the workout.
Consider Possible Interactions with Other Medications
Interactions with medications should also be considered. Those taking antibiotics or HIV medications should ask their doctor whether or at what interval magnesium can be taken. According to Dr. Riedl, a time gap of at least two hours should be maintained. Even other supplements like calcium, iron, zinc, vitamin E, and protein can inhibit magnesium absorption.
Therefore, anyone planning to take magnesium long-term should consult their doctor to determine if it is advisable in their specific case and to avoid any potential interactions.