Potential Importance of Magnesium for Athletic Performance
What does magnesium do in the body?
Magnesium is an essential mineral that the body needs adequate levels of for maintenance of normal energy metabolism, cell growth, carbohydrate breakdown in the body, and protein synthesis (1). Magnesium is also involved in processes contributing to nerve conduction, muscle contraction, and blood pressure regulation (1). How does magnesium impact exercise? During exercise, magnesium is shuttled to the working muscle to help support nerve signaling for muscle contraction and also muscle contraction itself. If magnesium weren’t available, muscle function, and therefore exercise capacity, would fall apart. Magnesium, however, also helps contribute to the breakdown of carbohydrates, namely glucose, into fuel during exercise. Carbohydrate breakdown is one of the most common ways in which the body obtains fuel for working muscle, particularly during intense exercise.
How much magnesium do athletes need each day?
The recommended dietary allowance (RDA) for magnesium in healthy adults is 400-420 mg/day for males and 310-320 mg/day for females (1,2). These intake levels are likely much higher for athletes, particularly for endurance athletes exercising for many hours each week. There is some recent evidence to suggest that many athletes may be deficient in magnesium levels due to inadequate intake of magnesium-rich foods or due to the low bioavailability of magnesium in humans (i.e., not all magnesium consumed in food can be digested, absorbed, and utilized in the body) (3).
What does research suggest are the benefits of adequate magnesium levels in the body for athletic performance?
Chronic low levels of magnesium in the body may be related to less than optimal exercise performance, which would make sense given the important roles that magnesium plays in the body. Unfortunately, there has not been much research examining the role of magnesium on performance outcomes in humans. There is some evidence coming from a mix of animal studies and human studies to suggest that adequate magnesium levels in the body is related to enhanced muscular strength and a reduction in the rate of lactate accumulation in the body during exercise (1). These outcomes would make sense given the role that magnesium plays in muscle contraction/relaxation. However, the reduced rate of lactate accumulation is interesting, particularly for endurance athletes as the lactate threshold (i.e., the point at which lactate rapidly and exponentially accumulates in the body) is highly related to endurance performance. Magnesium may help slow the rate of lactate accumulation due to its role in carbohydrate metabolism or because it seems to reduce the oxygen needs of working muscle (i.e., the less oxygen a muscle needs during exercise the lower the intensity of work is required to produce the same power output or speed) (1). Furthermore, very recent evidence suggests that magnesium supplementation may improve running time trial performance and impact post-exercise recovery, including perceived soreness and inflammatory cytokine production in the body, when compared to a placebo (2).
What does this mean for YOU as an endurance athlete or coach?
It seems that adequate magnesium levels in the body, much like all other essential vitamins and minerals, is of great importance for optimal athletic performance. The following are a few take-home messages for magnesium intake and athletic performance based on recent research:
Adequate magnesium intake is important, and many athletes may fall short of adequate magnesium intake.
Maintaining adequate magnesium levels in the body is likely to optimize athletic performance, potentially including:
a. muscle function and strength
b. carbohydrate metabolism during exercise
c. the rate of lactate accumulation during exercise
d. improving endurance performance
e. enhancing recovery from repeated intense exercise sessions
However, it is important to note that there is still much research needed to be done to confirm these roles that magnesium plays in endurance performance (1-3).
Now, how do you ensure that you are eating a diet with plenty of magnesium to make sure your body is operating at full capacity during exercise and while recovering? Magnesium-rich foods include (see image below for foods high in magnesium):
· Nuts
· Seeds
· Fruits
· Vegetables
· Whole grains
References:
1. Zhang Y, Xun P, Wang R, Mao L, He K. Can magnesium enhance exercise performance?. Nutrients. 2017 Sep;9(9):946.
2. Steward CJ, Zhou Y, Keane G, Cook MD, Liu Y, Cullen T. One week of magnesium supplementation lowers IL-6, muscle soreness and increases post-exercise blood glucose in response to downhill running. European Journal of Applied Physiology. 2019 Dec 1;119(11-12):2617-27.
3. Heffernan SM, Horner K, De Vito G, Conway GE. The role of mineral and trace element supplementation in exercise and athletic performance: A systematic review. Nutrients. 2019 Mar;11(3):696.
Happy training, racing, and recovering!
-Ryan Eckert, MS, CSCS
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