Are athletes deficient in magnesium?

December 24, 2025 •

4 min read

Research indicates that up to 22% of elite athletes may be clinically deficient in magnesium due to the increased physiological demands of intense training and competition. The high physical stress experienced by active individuals, coupled with potentially inadequate dietary intake, puts them at a greater risk for magnesium deficiency than the general population.

Quick Summary

Intense training and high metabolic demands put athletes at increased risk for magnesium deficiency, impacting energy production, muscle function, and recovery. Factors include increased sweat loss, restrictive diets, and processing of magnesium-rich foods, necessitating a focus on dietary sources and potential supplementation to maintain optimal levels.

Key Points

Increased Risk for Athletes: Intense training and high sweat loss significantly raise an athlete's magnesium needs, increasing their vulnerability to deficiency.
Core Functions Impacted: Magnesium is crucial for energy production, muscle contraction and relaxation, and effective post-exercise recovery.
Deficiency Symptoms: Common signs of low magnesium include muscle cramps, fatigue, delayed recovery, and poor sleep quality, all of which hinder performance.
Diet First Approach: The best strategy involves consuming magnesium-rich foods like leafy greens, nuts, and seeds to maintain adequate levels.
Supplementation for Optimization: For athletes with higher needs or insufficient dietary intake, supplements like magnesium glycinate or citrate can be effective when used under professional guidance.
Bone and Cardiovascular Health: Adequate magnesium is vital for maintaining bone density and supporting cardiovascular function, both critical for athletic longevity.

Magnesium is a critical mineral involved in over 300 biochemical reactions in the human body, playing a fundamental role in processes vital for athletic performance. From energy production and muscle function to nerve signaling and recovery, its importance cannot be overstated. However, the rigorous demands placed on an athlete's body—including increased metabolism, significant sweat loss, and sometimes restricted calorie intake—can quickly deplete magnesium stores, making them particularly vulnerable to deficiency.

Why Athletes Are More Susceptible to Magnesium Deficiency

Several factors contribute to the higher risk of magnesium deficiency in athletes compared to sedentary individuals. Understanding these root causes is the first step toward effective prevention.

Increased Requirements: Intense and regular physical activity, especially endurance training, significantly raises the body's need for magnesium. Requirements may increase by 10–20% or more for those engaging in strenuous exercise.
Sweat and Urinary Loss: During prolonged exercise, especially in hot conditions, athletes lose essential electrolytes, including magnesium, through sweat. Additionally, exercise may cause a temporary reduction in kidney function, leading to increased urinary excretion of magnesium.
Suboptimal Dietary Intake: Despite the importance of magnesium, many individuals, including athletes, fail to meet the recommended daily intake through diet alone. This is often due to reliance on processed foods, which are low in magnesium, or engaging in restrictive dieting for weight control.
Stress: The physical and mental stress of training and competition can further deplete magnesium levels. Stress hormones like cortisol can interfere with the body's ability to utilize magnesium effectively.

Key Symptoms of Low Magnesium in Athletes

Recognizing the signs of low magnesium is crucial for athletes. While some symptoms are general, others are more specific to athletic performance and recovery.

Muscle Cramps and Spasms: One of the most classic signs of low magnesium, which compromises muscle relaxation after contraction.
Fatigue and Low Energy Levels: Magnesium is essential for ATP energy production. Inadequate levels can impair this process, leading to premature exhaustion during workouts and persistent fatigue.
Impaired Recovery: Athletes with low magnesium may experience prolonged muscle soreness, slower tissue repair, and less effective recovery from strenuous training.
Reduced Performance: Deficiencies can lead to a drop in endurance, strength, and overall athletic output.
Poor Sleep Quality: Magnesium has a calming effect on the nervous system and is vital for deep, restorative sleep, which is critical for recovery and performance.
Increased Injury Risk: Poor muscle function and a decrease in bone mineral density associated with low magnesium can raise the risk of injury, including stress fractures.

The Role of Magnesium in Athletic Performance

Magnesium's multifaceted contributions to the body have a direct impact on an athlete's ability to train, perform, and recover effectively.

Energy Production

Magnesium is essential for activating adenosine triphosphate (ATP), the body's primary energy currency. Without sufficient magnesium, the energy conversion process becomes inefficient, hindering performance and increasing fatigue. It also helps transport blood glucose into muscles for fuel, delaying the onset of muscle tension-causing lactate.

Muscle Function

Magnesium acts as a natural calcium channel blocker, facilitating the relaxation of muscle fibers following contraction. This opposition to calcium is key to preventing muscle cramps, stiffness, and spasms. It also influences neuromuscular function, ensuring proper nerve signal transmission to the muscles.

Enhanced Recovery

Beyond muscle function, magnesium aids recovery by helping to regulate inflammation and oxidative stress, which are a natural result of intense exercise. This can help reduce muscle soreness and shorten recovery periods, allowing for more consistent training. Magnesium's calming effects also promote better sleep, a vital component of recovery.

Bone Health

Magnesium works with calcium and vitamin D to support healthy bone mineral density. For athletes who put their skeletal systems under repetitive stress, maintaining bone integrity is crucial for preventing stress fractures and other injuries.

Supplementation vs. Dietary Intake for Athletes


Feature	Dietary Intake	Magnesium Supplementation
Source	Whole foods like leafy greens, nuts, seeds, whole grains.	Tablets, capsules, powders, topical sprays, or epsom salts.
Absorption	Generally well-absorbed, especially from food sources.	Varies by form. Chelated forms (glycinate, malate) are highly bioavailable.
Usage	Foundation of magnesium intake for long-term health.	Best for correcting deficiencies, addressing specific needs (e.g., sleep, energy), or when dietary intake is insufficient.
Risk of Overdose	Very low from food sources alone, as kidneys regulate excess.	Possible, leading to digestive issues like diarrhea. Always follow recommended doses.

Magnesium-Rich Foods to Prioritize

Leafy Greens: Spinach, kale, and Swiss chard.
Nuts and Seeds: Pumpkin seeds, chia seeds, almonds, and cashews.
Whole Grains: Brown rice, quinoa, and whole wheat bread.
Legumes: Black beans, chickpeas, and lentils.
Dark Chocolate: Especially 70% or more cacao.
Avocados: Rich in magnesium and healthy fats.
Fatty Fish: Salmon and mackerel.

How to Ensure Adequate Magnesium Intake

Athletes should prioritize a balanced diet rich in magnesium-containing foods. For those with higher needs that cannot be met through diet, supplementation may be considered. Common supplements include magnesium glycinate and citrate, known for good absorption. Consulting a healthcare professional or dietitian is advised to determine the best approach. Additional information can be found on the {Link: NIH fact sheet on magnesium https://ods.od.nih.gov/factsheets/Magnesium-HealthProfessional/}.

Conclusion

Athletes are at an increased risk of magnesium deficiency due to higher physiological demands and loss through sweat. Low magnesium can negatively impact performance, recovery, and overall health, leading to symptoms like cramps and fatigue. Maintaining optimal magnesium levels through diet and, if necessary, targeted supplementation is crucial for supporting essential bodily functions and achieving peak athletic performance.

Frequently Asked Questions

Athletes have a higher metabolic rate and lose more magnesium through sweat and urine during intense exercise, increasing their daily requirements by an estimated 10–20% compared to non-athletes.

Key indicators of low magnesium in athletes include increased muscle cramps and spasms, persistent fatigue, poor sleep quality, slow recovery after workouts, and a noticeable drop in athletic performance.

Yes, magnesium is essential for proper muscle relaxation. Insufficient levels can lead to cramps and spasms, so maintaining optimal magnesium status can help prevent these issues, particularly in endurance events.

Highly bioavailable forms like magnesium glycinate and magnesium citrate are often recommended for athletes. Magnesium glycinate is favored for recovery and sleep, while magnesium malate may support energy production.

Athletes can boost their dietary magnesium by incorporating foods such as spinach, pumpkin seeds, almonds, black beans, whole grains, and dark chocolate into their daily meals.

The timing can depend on your goals. Some experts suggest taking magnesium before a workout to support energy. For recovery and improved sleep, taking it in the evening post-workout is often recommended.

Yes, excessive intake from supplements can cause gastrointestinal side effects like diarrhea, nausea, and abdominal cramps. It is important to follow recommended dosages and consult a healthcare professional.