Dana Eshelman, MS, RDN, CSSD, METS I
Magnesium (Mg) is an essential mineral that is involved in over 600 cellular reactions in the human body including protein synthesis, nerve and muscle function, blood sugar control, and blood pressure regulation. Magnesium plays a role in the transport of calcium and potassium across the cell membrane, which is vital for normal heart rhythm, nerve impulse conduction, and muscle contraction. It also contributes to the structure of bone and is required for producing DNA and RNA.
As an athlete, the role of magnesium that may interest you most is the role it has in how the body makes and uses energy. This is how you can level up as an athlete by optimizing both performance and recovery.
Research shows a positive association between magnesium status and muscle performance including:
grip strength
lower-leg power
knee extension torque
ankle extension strength
maximal isometric trunk flexion
rotation
jumping performance
Recommended Daily Allowance and Inadequacy:
Despite the known importance of magnesium intake, over 68% of Americans fail to get the recommended amount. Recommended Daily Allowance (RDA) for the average U.S. adult male is 400-420 mg and 310-320 mg for females. As an athlete, you want to consider the volume, intensity, and frequency of exercise as strenuous exercise can increase magnesium losses by up to 20% through sweat and urine. Magnesium losses are seen in athletes of all sports and body sizes independent of age, skin color, and gender.
Populations at increased risk of magnesium deficiency:
Weight class sports or sports with a focus on aesthetics can be at increased risk due to suboptimal energy intake.
Gastrointestinal disease including Crohn's disease, gluten sensitive enteropathy (celiac disease), and regional enteritis can lead to magnesium depletion
Type 2 diabetes and insulin resistance can increase urinary magnesium excretion
Older adults have decreased magnesium intake, decreased magnesium absorption in the gut, and increase renal magnesium excretion.
Signs of deficiency:
leg cramps
dizziness
digestive issues
fatigue
abnormal heart rhythm
headaches
Do you Need to Supplement?
As an athlete, supplementation may be necessary to avoid deficiency during high training volume, intensity, and/or based on season.
It is important to note: not all forms of magnesium are treated the same. There are multiple forms of magnesium including: magnesium citrate, magnesium chloride, magnesium oxide, magnesium sulfate, and magnesium hydroxide. Liquid forms of magnesium citrate and chloride are generally better tolerated and absorbed when compared to solid tablets like oxide and sulfate.
Magnesium bisglycinate is a form of magnesium that is combined with the amino acid glycine to help improve the absorption rate of magnesium and improve tolerance. Glycine also promotes relaxation and stress reduction. This is a great option for athletes to promote recovery from training.
Just like any supplement, too much can cause adverse side effects. Magnesium can act as a laxative and may cause diarrhea. It is not recommended to take more that 250 mg of supplemental magnesium per day.
Food Sources of Magnesium:
Pumpkin seeds, hulled, roasted (1 oz) | 150 mg magnesium |
Chia Seeds (1 oz) | 111 mg magnesium |
Almonds, roasted (1 oz) | 80 mg magnesium |
Spinach, cooked (1/2 c) | 78 mg magnesium |
Swiss chard, cooked (1/2 c) | 75 mg magnesium |
Dark chocolate, 70 to 85% cocoa (1 oz) | 64 mg magnesium |
Black beans, boiled (1/2 c) | 60 mg magnesium |
Quinoa, cooked (1/2 c) | 60 mg magnesium |
Edamame, cooked (1/2 c) | 50 mg magnesium |
Potatoes, one medium with skin | 48 mg magnesium |
Yogurt, plain, low fat (8 oz) | 42 mg magnesium |
Bananas, 1 medium | 32 mg magnesium |
Milk, nonfat (1 c) | 24 to 27 mg magnesium |
Collard greens (1/2 c) | 25 mg magnesium |
Tips to Getting Enough Magnesium:
Include at least 3-4 fist sized portions of veggies per day
Include at least 2-3 fist sized portions of fruits per day
Opt for whole grains over refined grains
Choose 1/4 cup (1 ounce) of nuts or seeds per day
Enjoy 1/2 cup cooked legumes 5-7 days per week
Takeaways:
The more you train, the more magnesium you need in your diet. At DDN, we are all for amping up your nutrition to include magnesium-rich foods to support your body, but also realize that is not always possible. Magnesium-rich foods are also high in fiber, which may not be well tolerated with high training volume. This is where supplementation may be indicated.
If you need help with your nutrition or are looking to amp up your nutrition for performance, DDN is here as a resource to help you develop a personalized plan!