Magnesium: We do sweat (out) the small stuff

In this 4-part series on essential micronutrients for the endurance athlete, we will examine how these micronutrients are used by the athlete’s body, what processes they impact, foods that increase our intake and standalone supplements. These micronutrients can be easily overlooked and that is why we have decided to focus some attention on these important nutrients.

Magnesium (Mg)

This very important element plays a vital role in more than 300 different processes and enzymatic reactions throughout the body and brain. As endurance athletes, we are accustomed to focusing on the main elements of sodium (Na) and potassium (K) with our workout hydration and nutrition choices, but a significant magnesium deficiency can become a performance limiter. While the etiology of muscle cramping during exercise is very complex, there is extensive clinical evidence that magnesium assists in modulating the utilization of both sodium and potassium for muscle contraction and preventing a deficient state can be variable in preventing cramping.

Endurance athletes typically become deficient in magnesium due to 2 major processes. First, the endurance athlete’s muscle contract exponentially more than non-athletes and with much more force which requires more magnesium over time to fuel the muscle contraction process. Secondly, significant magnesium is lost through sweat, urination & bowel movements which are typically increased due to training and hydration.

A study published in The American Journal of Clinical Nutrition stated that 79% of adults do not consume enough magnesium. That is “average adults” and not just athletes. The good news is that while magnesium is an important element, it is readily available in many foods. In general, rich sources of magnesium are greens, nuts, seeds, dry beans, whole grains, wheat germ, wheat and oat bran. The USDA believes the recommended dietary allowance for magnesium for adult men is 400 - 420 mg per day and 310 - 320 mg per day for adult women. Almonds, pistachios, and pumpkin seeds are great portable sources of magnesium.

If you are interested in a standalone supplement, as a pharmacist, I recommend SlowMag® Mg Muscle + Heart (https://www.slowmag.com/our-products/slowmag-mg-muscle-heart/) because it is gentle on the stomach and is slow release. Another magnesium supplement I currently have had good results with is MGSPORT (https://mgsport.biz/products/high-absorption-magnesium) for being gentle and containing Vitamin B, D & E. The most common side effect of magnesium supplementation is loose stools as magnesium can act as laxative as it gets absorbed in the lower gastrointestinal tract. Should that occur, reduce your dosage or take on alternating days. Additionally, it is widely suggested to take magnesium before bedtime as it can aid in sleep.

As an athlete, it is important to also consider the micronutrients that are essential to peak performance. Next, we will review our 2nd micronutrient, Vitamin D, it’s function in the athlete, foods to eat and supplementation.

Resources:

Dai Q, Zhu X, Manson JE, et al. Magnesium status and supplementation influence vitamin D status and metabolism: results from a randomized trial. Am J Clin Nutr. 2018;108(6):1249-1258. https://pubmed.ncbi.nlm.nih.gov/30541089/. Accessed August 21, 2022.

Disclaimer: S3 Multisport has not received endorsement, free product, financial compensation, etc., for any products that we discuss. Our recommendations are based on our professional judgement and experience and make no claim that these products are superior to other products on the market.