Magnesium for muscle function and performance

October 2, 2018
Volume: 
21
Issue: 
7

Magnesium is a mineral that is a crucial cofactor for over 300 enzymes, playing a core role in the structure and function of the human body. Magnesium’s broad-reaching importance extends to areas including energy production, the synthesis of DNA and proteins, structural roles in bone and cells, facilitating cellular signaling, and nerve function.1 With its breadth of reach and influence over human physiology, it’s not surprising that magnesium is a critical mineral for muscle function.

Magnesium influences muscle performance by participating in energy metabolism and maintenance of muscle contraction and relaxation. Research further shows that magnesium deficiency can lead to a disruption of neuromuscular function—and that high levels of physical activity increase the body’s demand for magnesium. Further studies in individuals on a strength training program have found that suboptimal magnesium status leads to decreased endurance, while higher magnesium intake in aerobic exercise is associated with a requirement for less oxygen and improved cardiorespiratory fitness.2

Although maintaining optimal levels of magnesium is essential for all, athletes and others who are physically active may have increased requirements for magnesium. Similarly, those with sarcopenia as well as those experiencing other muscular issues related to the aging process may also need higher intakes of magnesium. However, according to USDA data, almost half of all individuals have magnesium intake levels below the Estimated Average Requirements (EAR) for this nutrient. Strikingly, for adults aged 71 and over, this percentage rises to two-thirds of the population.3 The Recommended Dietary Allowance (RDA) for magnesium ranges from 400 to 420 mg per day for males aged 14 to over 70. For women, the RDA for those aged 14 to over 70 ranges between 310 and 320 mg per day.

In addition to nearly 60% of adults falling short of these guidelines, reviews suggest that magnesium consumption in most athletes falls well below amounts that are considered adequate.4 As magnesium is an electrolyte, strenuous exercise causes a significant amount to be lost through urine and sweat. This can increase magnesium requirements by 10%-20%.5

Magnesium and Muscle Function

A recent review coauthored by Mario Barbagallo and Ligia Dominguez from the University of Palermo (Palermo, Italy) outlines several important ways in which magnesium impacts muscle function and performance.6 As physical exertion depletes magnesium and leads to increased oxidative stress, higher levels of reactive oxygen species, or free radicals, are generated. These free radicals may contribute to the development of muscle fatigue. Magnesium has antioxidant effects that can confer protection to muscle tissue.

Additionally, magnesium plays a fundamental role in mitochondrial energy production. Over one-third of total cellular magnesium is found in the mitochondria and is present complexed together with adenosine triphosphate (ATP) and as a component of membranes. Magnesium is, therefore, critical for basic mitochondrial functions, including the production of ATP, and confers a protective role to skeletal muscle mitochondria.

Furthermore, inflammation is a critical factor in reduced muscle performance. Poor magnesium status is known to exacerbate the inflammatory state and leads to increased circulating levels of pro-inflammatory markers. Magnesium intake, on the other hand, has repeatedly been found to reduce systemic inflammation, including significant reductions in the cytokine IL-6 and C-reactive protein (CRP) levels, two markers of inflammation.

Magnesium may also influence muscle function and exercise performance in another important way. Hsuan-Ying Chen and colleagues from Providence University in Taichung, Taiwan, found that administering magnesium to animals prior to a treadmill exercise led to increased glucose availability in muscle and brain tissue while increasing the clearance of lactate from muscle.7 This central role of magnesium in glucose utilization and metabolism is critical for shuttling glucose to where it’s needed in the body during exertion.

Benefits of Optimal Intake across Demographics

Alisa Welch and colleagues from the University of East Anglia (Norwich, UK) recently conducted two relevant studies evaluating the significance of magnesium intake for muscle health across broad spectrums of the population.

In one study, the researchers analyzed data from a cohort of 156,575 men and women aged 39-72 to assess the impact of dietary levels of magnesium on skeletal muscle and bone health parameters.8 They found that higher dietary intakes of magnesium were positively associated with greater grip strength, skeletal muscle mass, and bone mineral density in both men and women. In men over the age of 60, the relevance of higher magnesium intake as it relates to grip strength was even more exaggerated compared with younger men, emphasizing the importance of ensuring optimal magnesium consumption in this group. Furthermore, when the researchers analyzed the benefits of greater magnesium intake across this population versus the annual losses of bone mineral density and skeletal muscle with age, they concluded that the findings were of clinical significance in terms of higher magnesium intake stemming these decreases over time. Dietary levels of magnesium may, therefore, have relevance for prevention of sarcopenia, frailty, falls, and fractures.

In a second study, Welch and colleagues analyzed cross-sectional data from 2,570 women aged 18 to 79 years to determine the effect that dietary magnesium intake has on age-related skeletal muscle loss, power, and chronic low-grade inflammation.9 They found that higher dietary magnesium intake was significantly positively associated with skeletal muscle mass (fat-free mass as a percentage of body weight), leg explosive power (a measure of the force and velocity of muscle contraction of the quadriceps), and circulating levels of the inflammation marker CRP. Quite remarkably, the difference in leg explosive power was shown to be more than 24% greater in those women with the highest versus lowest magnesium intake. In terms of inflammation, the differences in CRP concentrations is significant as magnesium may play a greater role in skeletal muscle conservation in older women via attenuating the production and effect of inflammatory cytokines.

Moreover, an analysis from the Maastricht Sarcopenia Study in the Netherlands compared nutrient intakes in 227 older adults (aged 65 or older) and found that individuals with sarcopenia had significant nutritional differences in five nutrients compared to those without sarcopenia.10 Sarcopenic individuals had a 10%-18% lower intake of omega-3 fatty acids, vitamin B6, folic acid, vitamin E, and magnesium, with the difference in magnesium intake approaching 12% between the groups.

These data taken together substantiate the critical importance of ensuring optimal magnesium intake for skeletal muscle health through the lifespan.

References: 
  1. Linus Pauling Institute. “Magnesium.” 2014. https://lpi.oregonstate.edu/mic/minerals/magnesium Retrieved August 5, 2018.
  2. Zhang Y et al. “Can magnesium enhance exercise performance?” Nutrients. Published online August 28, 2017.
  3. NHANES 2005-2006. “What We Eat in America.” www.ars.usda.gov/ARSUserFiles/80400530/pdf/0506/usual_nutrient_intake_vitD_ca_phos_mg_2005-06.pdf. Retrieved 5 August 5, 2018.
  4. Volpe SL. “Magnesium and the athlete.” Current Sports Medicine Report, vol. 14, no. 4 (July-August 2015): 279-283
  5. Nielsen FH et al. “Update on the relationship between magnesium and exercise.” Magnesium Research, vol. 19, no. 3 (September 2006): 180-189
  6. Barbagallo M et al. “Magnesium, oxidative stress, and aging muscle.” Aging. (December 2014): 157-166
  7. Chen HY et al. “Magnesium enhances exercise performance via increasing glucose availability in the blood, muscle, and brain during exercise.” PLoS One. Published online January 20, 2014.
  8. Welch AA et al. “Dietary magnesium may be protective for aging of bone and skeletal muscle in middle and younger older age men and women: Cross-sectional findings from the UK Biobank Cohort.” Nutrients. Published online October 30, 2017.
  9. Welch AA et al. “Dietary magnesium is positively associated with skeletal muscle power and indices of muscle mass and may attenuate the association between circulating C-reactive protein and muscle mass in women.” Journal of Bone and Mineral Research, vol. 31, no. 2 (February 2016): 317-325
  10. Ter Borg S et al. “Differences in nutrient intake and biochemical nutrient status between sarcopenic and nonsarcopenic older adults-results from the Maastricht Sarcopenia Study.” Journal of the American Medical Directors Association, vol. 17, no. 5 (May 1, 2016): 393-401
  11. Córdova Martínez A et al. “Effect of magnesium supplementation on muscular damage markers in basketball players during a full season.” Magnesium Research, vol. 30, no. 2 (May 1, 2017): 61-70
  12. Talebi V et al. “The effects of magnesium supplementation on electromyography indexes of muscle fatigue after intense anaerobic exercise.” International Journal of Applied Science in Physical Education, vol. 2, no. 2 (April 14, 2018): 58-66
  13. Veronese N et al. “Effect of oral magnesium supplementation on physical performance in healthy elderly women involved in a weekly exercise program: a randomized controlled trial.” American Journal of Clinical Nutrition, vol. 100, no. 3 (September 2014): 974-981