Do you experience persistent fatigue despite your training sessions? Do nighttime cramps or tense muscles interfere with your performance? These warning signs may reveal a magnesium deficiency, a common problem among athletes that hinders recovery and overall well-being. In France, 70% of people are deficient in magnesium.
Magnesium is an essential mineral that actively participates in more than 300 enzymatic processes, particularly energy production, proper muscle function, and nervous system balance. For those who engage in intense physical activity, the importance of magnesium is increased tenfold: sustained exertion and sweating accelerate its elimination, which promotes the rapid onset of signs of magnesium deficiency.
The main causes of magnesium deficiency
Magnesium deficiency often results from a combination of factors that add up:
- The modern diet, depleted of minerals due to depleted soils and ultra-processed products, is one of the leading causes.
- Drinking water with too few minerals
- Chronic stress also increases requirements because it accelerates the elimination of magnesium through urine.
- Among athletes, losses related to sweating and repeated training further worsen the deficiency.
- Excessive consumption of coffee, tea, alcohol, or energy drinks interferes with absorption and accelerates the excretion of the mineral.
- Certain medical conditions, digestive disorders, use of diuretics, and poorly controlled diabetes also significantly reduce reserves.
- Finally, restrictive diets or diets low in vegetables, nuts and seeds, and whole grains contribute to insufficient intake.
Understanding these causes makes it possible to adopt a targeted strategy to quickly restore healthy magnesium levels.
How to recognize a magnesium deficiency
The symptoms of magnesium deficiency often develop insidiously: persistent fatigue, recurring muscle cramps (especially at night or during exercise), and unexpected muscle spasms. These symptoms reflect a disruption in the alternation between muscle contraction and relaxation, demonstrating how magnesium relaxes muscles and ensures harmonious muscle function.
Muscle stiffness and cramps
Persistent stiffness after exercise and abnormally long recovery times are also indicators of magnesium deficiency. The body then struggles to relax muscle fibers, causing muscle pain and increased nervousness. When the body lacks magnesium, the nervous system remains constantly hypervigilant.
Magnesium plays an active role in electrolyte balance, together with calcium, sodium and potassium. This balance is crucial for proper neuromuscular function and a regular heart rhythm. Magnesium acts as a regulator of the exchange of these minerals across cell membranes, ensuring a harmonious alternation between muscle contraction and relaxation. A deficiency can trigger cramps, muscle spasms and even cases of tetany.
- Prevent nighttime cramps: Adequate magnesium intake promotes muscle relaxation during the night and prevents sudden contractions.
- Regulate calcium: By controlling the entry of calcium into the muscles, magnesium reduces the risk of involuntary spasms.
- Protect the heart: A proper electrolyte balance reduces the risk of arrhythmia during prolonged exertion, especially in hot weather.
- Maintain hydration: Magnesium works with sodium and potassium to maintain proper cell hydration.
In severe cases, magnesium deficiency can lead to calcium and potassium imbalances (hypocalcemia and hypokalemia), which weaken the cardiovascular system. Endurance athletes, who lose a great deal of electrolytes through sweating, are particularly at risk. That is why it is important to obtain magnesium from different sources every day to preserve these vital functions.
Anxiety, stress, nervousness and lack of motivation
Older people and endurance athletes are particularly at risk, as their increased losses through sweating worsen the deficiency. Consequences: low mood, increased nervousness and reduced motivation, since magnesium contributes to the production of neurotransmitters involved in emotional balance.
Magnesium plays a key role because it facilitates the activation of GABA receptors (gamma-aminobutyric acid), the brain's primary inhibitory neurotransmitter. Its role is to slow neural activity, calm the mind, and reduce neuromuscular excitability. Both also help lower cortisol, the stress hormone.
Fatigue and lack of restorative sleep
Your body's magnesium level plays a direct role in the synthesis of ATP, the energy molecule in cells. A deficiency causes premature physical fatigue and a drop in power, while supplementation with magnesium bisglycinate, renowned for its optimal bioavailability, helps restore electrolyte balance and improve recovery.
Sleep is the key phase during which the body regenerates its tissues and restores its energy reserves. Sleep disorders—difficulty falling asleep or frequent awakenings—are among the most characteristic magnesium deficiency symptoms.
Because magnesium has a modulating role in the nervous system, insufficient levels maintain a state of hyperexcitability, prolong nervousness, and prevent complete muscle relaxation. Without sufficient magnesium, fatigue builds up, recovery stagnates, and performance declines.
Discover the complete list of symptoms of magnesium deficiency recognized by the medical community: neuromuscular hyperexcitability, tremors, fasciculations, muscle spasms, and heart rhythm disorders. These are all signs of magnesium deficiency that call for immediate correction.
Foods naturally rich in magnesium
One of the best ways to maintain optimal magnesium levels is to regularly include foods that are naturally rich in it. A varied diet consisting of green vegetables, nuts, seeds, and whole grains not only helps cover some of your daily needs.
Here are the most interesting sources for athletes, along with their approximate magnesium content and physiological benefits per 100 g:
- Pumpkin seeds: 530 mg
- Almonds: 270 mg
- Cashews: 260 mg
- 70% dark chocolate: 230 mg
- Cooked spinach: 80 mg
- Cooked quinoa: 60 mg
- Lentils: 35 mg -
- Avocado: 30 mg
- Banana: 27 mg
Why choose magnesium bisglycinate
Not all forms of magnesium are equal. Although magnesium citrate, oxide, and carbonate do provide this essential mineral, their absorption varies considerably and they can cause digestive discomfort. Thanks to its chelated formula, magnesium bisglycinate protects the mineral during digestion and facilitates its passage into the bloodstream.
Digestive tolerance and effectiveness
Magnesium bisglycinate (one magnesium atom for two molecules of lysine, an amino acid in the BCAA family) offers much better bioavailability than traditional forms. Its chelated structure with glycine forms a protective barrier around the mineral, thereby improving its intestinal absorption. This feature prevents undesirable chemical reactions that could reduce the effectiveness of the dietary supplement.
Result: excellent digestive tolerance. Unlike oxide or carbonate, which can have an inconvenient laxative effect, bisglycinate maintains pH and protects your digestive system while providing a regular magnesium supply without discomfort.
- Optimal absorption: the chelated structure easily passes through the intestinal wall to nourish the muscles and nervous system.
- Prolonged release: the mineral is released gradually, maintaining a stable blood level throughout the day.
- No side effects: no more digestive problems caused by other less well-tolerated forms.
- Endurance benefits: particularly suitable for intensive training, long sessions, or competition periods.
Vitamin B6 and absorption
Magnesium is generally combined with vitamin B6, which plays an essential role. It enables the mineral to enter cells, thereby increasing its role in energy production and muscle function. Without it, some of the magnesium would remain trapped in the bloodstream.
Together, magnesium and vitamin B6 stimulate protein metabolism, aid muscle recovery after exercise, reduce persistent fatigue, and improve resistance to chronic stress associated with repeated training.
Optimal sports dosage
Your magnesium needs depend on the intensity and frequency of your training. 150 mg covers the recommended daily amount for an active athlete. Adjust your magnesium intake according to your training load and personal goals.
Take one capsule with breakfast to boost your energy metabolism from the morning onward, then a second with dinner to relax your muscles and prepare your nervous system for sleep. This routine maintains stable blood magnesium levels and promotes both performance and recovery.
Effects of magnesium on recovery
Good recovery is essential for progressing in your sport and maintaining long-term performance. Magnesium plays a key role in muscle repair, cellular energy production, and nervous system regulation. Understanding these mechanisms allows you to optimize your diet and maximize the benefits of every workout.
Magnesium deficiency often manifests as persistent fatigue, cramps, slower recovery after exercise, and greater sensitivity to muscle tension. In athletes, sweating and intense training increase daily needs for this mineral. A deficiency can disrupt ATP production and proper muscle function. Learn how magnesium combats fatigue and cramps.
Magnesium's effects on the immune system
Magnesium plays an essential role in the proper functioning of the immune system. It is involved in the production and activation of defense cells such as lymphocytes, which protect the body against infections. Sufficient magnesium levels also help regulate inflammation, preventing excessive reactions that drain the body. During periods of stress, intense training, or lack of sleep, magnesium stores decrease, which can weaken the immune response. By supporting nervous system balance, restorative sleep, and cortisol reduction, magnesium indirectly but powerfully helps strengthen the body's natural defenses and maintain good health.
Testing and confirming the deficiency
Before purchasing magnesium capsules, several clues can help you assess your condition and avoid diagnostic errors.
- Daily tracking: for two weeks, record the frequency of cramps, your energy level, and the quality of your sleep.
- Dietary assessment: analyze your intake of magnesium-rich foods such as spinach, nuts, whole grains, and lentils.
- Sports habits: observe the intensity, duration, and frequency of your sessions, as well as the climatic conditions (heat increases losses).
A blood test can partially confirm a deficiency, but blood magnesium levels do not accurately reflect cellular stores. Red blood cell testing is more precise but rarely prescribed. In practice, observing symptoms combined with the effects of a short magnesium course often makes it possible to reach a conclusion quickly. This simple approach helps you adapt your diet or supplementation effectively.
The benefits of Mulebar magnesium
Choose a highly bioavailable, well-tolerated supplement for tangible results. The Mulebar bisglycinate magnesium sports course, enriched with vitamin B6, perfectly meets athletes' metabolic needs and promotes optimal absorption. You are therefore choosing a high-performance, natural, and environmentally friendly product. Mulebar
Made in France, this supplement benefits from rigorous traceability through strict quality controls. The plant-based capsules are suitable for vegan athletes, and the recyclable and compostable packaging (cardboard and corn-based bioplastic) reduces its environmental impact. You therefore benefit from a product aligned with your values, without compromising on effectiveness or quality.
One bottle of 60 capsules provides a one-month course. The 2 daily capsules provide 1,400 mg of magnesium bisglycinate, equivalent to 150 mg of elemental magnesium (40% of the NRV), combined with 0.7 mg of vitamin B6 (50% of the NRV).
Pre-competition course plan
Start a course 2 to 4 weeks before an important deadline to replenish your stores and optimize recovery. Begin with one capsule in the morning and one in the evening, then adjust according to your training load and how you feel. You will generally notice a gradual reduction in headaches and irritability. For better absorption, leave at least 2 hours between taking magnesium and calcium or iron.
Take your supplement with a meal rich in carbohydrates or on an empty stomach, depending on your tolerance, to maximize bioavailability. This schedule maintains stable levels in your body throughout the day and prevents sleep disturbances associated with taking it too late. With this simple protocol, your body will approach the event with optimal reserves and minimal fatigue.
Magnesium: precautions, safety, and specific needs
Contraindications and drug interactions
Magnesium is generally well tolerated, but certain precautions are necessary. People with kidney impairment should avoid supplementation because their kidneys cannot properly eliminate excess minerals. Some forms of magnesium can interact with medications such as tetracycline antibiotics or bisphosphonates by reducing their absorption. Diuretics, proton pump inhibitors (PPIs), and certain heart medications can also affect magnesium levels. If you are undergoing long-term medical treatment, it is recommended that you seek professional advice before starting a course of supplementation.
Risks of overdose
Magnesium overdose is rare in healthy people because the body naturally excretes excess magnesium in the urine. However, excessive intake, often linked to poorly dosed or poorly tolerated supplements, can cause diarrhea, nausea, or digestive discomfort, especially with less bioavailable forms such as oxide or chloride. More serious symptoms, such as low blood pressure or heart problems, occur only in cases of severe kidney impairment. Following the recommended dosages and choosing well-absorbed forms such as bisglycinate helps limit any risk.
Magnesium and women: the menstrual cycle and PMS
Magnesium plays a valuable role in women’s well-being, particularly during the menstrual cycle. It helps relax the smooth muscles of the uterus, reducing menstrual cramps and tension. It also acts on neurotransmitters involved in stress management, helping ease the irritability, anxiety, and mood swings typical of premenstrual syndrome (PMS). Some studies show that adequate magnesium levels may also reduce cycle-related cravings, fatigue, and headaches. For many women, regular bisglycinate supplementation provides genuine support for coping better with these hormonal fluctuations.
Frequently asked questions
How can you tell if you have a magnesium deficiency?
Several symptoms may alert you to a magnesium deficiency. You may experience persistent fatigue, muscle cramps, especially at night or during exercise, and unpleasant tingling sensations. Other common signs of deficiency include sleep disturbances, irritability, and low energy. Athletes often notice these symptoms worsening during periods of intensive training with heavy sweating.
How can you raise your magnesium levels quickly?
To quickly correct a deficiency, eat foods naturally rich in magnesium, such as spinach, almonds, pumpkin seeds, or dark chocolate with at least 70% cocoa, or choose magnesium bisglycinate combined with vitamin B6. Take approximately 150 mg in the morning and evening with meals. Tip: avoid consuming foods containing iron or calcium at the same time, as they may interfere with magnesium absorption.
What illness causes magnesium deficiency?
Several medical conditions can cause a deficiency, including type 2 diabetes, inflammatory bowel disease, hyperthyroidism, and kidney problems. Certain medications, such as diuretics, also promote magnesium loss. In athletes, heavy sweating, an unbalanced diet, and increased needs often explain the signs of magnesium deficiency. Chronic stress, alcohol, and overly restrictive diets can also worsen the deficiency. If symptoms persist, do not hesitate to consult a healthcare professional.
What is the difference between marine magnesium and bisglycinate?
Marine magnesium is extracted from seawater and contains several forms of magnesium, including oxide, which is less well absorbed by the body. It therefore requires higher doses and may cause digestive discomfort in some people. Magnesium bisglycinate, on the other hand, is a chelated form in which magnesium is bound to two glycine molecules. This structure greatly improves its absorption, digestive tolerance, and effectiveness for muscles and nerves. For athletes or people prone to stress, bisglycinate is generally considered the most bioavailable and gentlest form for the stomach.
How long should a magnesium course last?
A course lasts from 1 to 3 months and can be renewed depending on the disappearance of the symptoms of magnesium deficiency.
