Magnesium for muscle function and performance

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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.

Magnesium Supplementation and Physical Performance

Clinical trials involving magnesium supplementation for improving athletic performance and muscle function have yielded mixed results; however, some recent studies point to positive benefits in professional and recreational athletes, as well as the elderly.

In one recent study conducted by Córdova Martínez Alfredo and colleagues from the University of Valladolid (Soria, Spain), researchers investigated the effects of magnesium supplementation on muscle damage in male professional basketball players.¹¹ Twelve elite basketball players who were members of a team were asked to supplement with 400 mg magnesium daily in the form of magnesium lactate during the entire basketball season (approximately 32 weeks). Blood samples assessing parameters of muscle damage were taken throughout the season at eight-week intervals. As a comparison, twelve college age students who played recreational basketball and competed in minor university leagues were used as a control group to assess baseline parameters. This group was not supplemented with magnesium.

Serum magnesium levels did not differ significantly at baseline between the professional players and the recreational players serving as controls. Over the course of the study, serum magnesium levels registered a decrease at the third timepoint with respect to the first and second timepoints; however, these levels recovered and were significantly higher at the fourth timepoint versus the third. Additionally, there was no significant increase in the parameters of muscle damage versus baseline levels in the professional athletes, indicating a protective effect on muscle tissue associated with magnesium supplementation.

In general, with exertion levels seen in these athletes, a rise in these markers of muscle damage is expected. The parameters assessed included myoglobin, lactate dehydrogenase, aldolase, serum urea, and total proteins, along with the liver enzymes ALT and AST. Overall, this small study supported the use of magnesium supplementation in elite athletes for preventing the normal drop seen in serum magnesium with intense physical activity as well as mitigating an increase in biochemical markers of muscle damage during the basketball season.

Another study aimed to assess the effect of magnesium on muscle fatigue. Conducted by researchers at the University of Mazandaran (Babolsar, Iran), the randomized controlled trial looked at the benefits of magnesium supplementation on muscular fatigue following intense anaerobic exercise.¹²

In this pilot study, 16 physically active male college-aged volunteers who exercised regularly for at least 30 minutes four days per week for the prior three months were randomly divided into a placebo groulp or a supplementation group. The subjects were asked to supplement with 350 mg of magnesium sulfate or placebo nightly before dinner for fourteen days. They underwent the Wingate test at the beginning of the trial period and again at the end. The Wingate test is a stationary bicycle test of exhausting physical anaerobic activity. It involves 30 seconds of maximal exertion (pedaling as fast as possible) following a five-minute warmup session.

Blood was drawn both prior to and after the test. The muscular activity of the right leg (three main muscle groups) was assessed by an electromyography (EMG) device. While in the placebo group a decline was noted in mean power frequency (an indicator of muscular motor unit fatigue) between pre-test and post-test numbers, magnesium supplementation led to significant increases in these values post-test, suggesting an increase in the ability of muscle fibers of the leg to continue to fire. Magnesium supplementation led to reduced muscular fatigue and enhanced performance on the Wingate test, while no significant changes were noted with placebo. The results of the study suggest that magnesium supplementation benefits muscle function during anaerobic exercise performance.

Earlier, Nicola Veronese from the University of Padova (Padova, Italy) led a study looking at the ability of magnesium to impact physical performance in healthy elderly individuals involved in a weekly exercise program.¹³

In the 12-week randomized controlled study, 139 women (average age of 71) were allocated to either a magnesium group (300 mg/day as magnesium oxide) or a control group (no intervention). The primary outcome assessed during the study at baseline and week 12 was a change in the Short Physical Performance Battery (SPPB), which consists of three objective physical function tests: 4-meter gait speed, repeated chair stands, and standing balance in increasingly challenging positions. Secondary outcomes included changes in peak torque isometric and isokinetic strength of the lower limbs and handgrip strength.

Baseline SPPB scores were similar between the supplement group and control group; however, at 12 weeks, magnesium supplementation led to significant improvements in total SPPB scores, chair stand times and 4-meter walking speeds. No significant changes were seen in the secondary measures of muscle strength. Overall, the authors concluded that 12 weeks of supplementation with magnesium improved physical performance in healthy elderly women and noted that those with magnesium intake lower than the recommended daily allowance saw the greatest benefits.

Benefits for All

Magnesium’s importance in muscle health and physical performance in individuals of all ages can’t be overemphasized. Its necessity for skeletal muscle function is indispensable.

As the majority of the adult population in the U.S. fails to meet basic RDA levels, improving magnesium intake is essential. In athletes, the influence of magnesium in improving athletic performance combined with the potential increased needs in those who are physically active necessitates a second look to ensure adequate intake in this group of individuals. After taking a closer look at improving dietary intake, a simple cost-effective approach would be to supplement with this mineral in at-risk populations. This could lead to better performance in athletes, better physical fitness with age, and better overall musculoskeletal health throughout life.

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Is magnesium awareness growing in active nutrition?

Evidence continues to build showing magnesium is crucial for muscle function, but are supplement shoppers getting the message? Nutritional Outlook interviewed one industry expert, Stephen Ashmead, MS, MBA, senior fellow for Balham Corp., Albion Minerals (Layton, UT), about how well consumers understand the link between magnesium and active nutrition and sports nutrition.

Nutritional Outlook: How aware are today’s sports nutrition customers about the role of magnesium in muscle function and performance?

Ashmead: While scientific evidence continually emphasizes the importance of proper magnesium intake, and despite the fact that consumers have access to more information about magnesium than ever before, research consistently shows that people aren’t getting the recommended amounts in their diet. According to the National Health and Nutrition Examination Survey (NHANES) 1999-2000, researchers found 68% of Americans consumed less than the recommended minimum daily intake (400 mg) of magnesium.

However, there is greater and growing awareness within the sports nutrition market of the many roles of magnesium. The lines between athletes and “lifestyle users” have blurred, and active nutrition is an important segment of the sports nutrition market. With growing interest in leading active lifestyles and increased participation in sports and fitness activities, the demands within this market are evolving. Both athletes and active-lifestyle consumers want supplements that help support specific goals for energy, endurance, performance, weight loss, muscle comfort, and overall wellness.

We are seeing tremendous growth for magnesium in this sector. Magnesium sales will continue to grow as more consumers recognize the benefit of adequate magnesium in their diets and lifestyles. They will use it to prevent deficiencies due to diets or other issues, and to support physiological function and their active lifestyles.

Can you highlight the importance of magnesium to athletic performance?

Magnesium is the catalyst or cofactor in many of the oxidative phosphorylation reactions, converting sugars into glycogen and ultimately ATP (adenosine triphosphate) needed for refueling in preparation for future exercise or athletic performance. Sports performance and exercise require a high supply of the energy produced by magnesium-sparked reactions.

As we exercise, the body burns through our glycogen stores. The longer and the more intense the exercise, the more glycogen we burn. Fast glycogen recovery or refueling is most important in athletes who train multiple times per day or participate in back-to-back events. In these individuals, a proper refueling strategy is essential, otherwise they put themselves at risk for poor performance and even injury.

Minerals play important roles in counteracting the impact that exercise performance can have on the body. Magnesium and zinc play important roles in fighting against oxidative stress and reducing inflammation, thereby reducing muscle damage. Magnesium is involved in a multitude of processes that impact muscle function, including oxygen uptake, electrolyte balance, and energy production. Proper magnesium intake can enhance exercise performance.

What kind of inroad has magnesium made in the sports nutrition market? Can you comment on the volume of sports nutrition products you see now incorporating magnesium?

According to the Nutrition Business Journal, magnesium supplements had almost 9% in sales growth in 2017. In fact, it is predicted that by next year, magnesium sales will overtake calcium as the single largest mineral sold in the market. Some of this growth can certainly be attributed to growing interest from the sports nutrition market, which is also growing steadily. Euromonitor reports that sports nutrition sales grew from US $7.3 billion in 2011 to $13.6 billion in 2017, and is expected to continue growing at nearly 8% CAGR by 2021.

What kind of synergistic benefits does magnesium have with other commonly used sports nutrition ingredients? Are you seeing those combinations featured in the end-product market today?

When formulating sports nutrition products, it is also important to consider the cognitive aspects, along with the physical benefits of the ingredients. Nootropics are gaining substantial interest in sports nutrition. Minerals such as iron, zinc, and magnesium play important roles in achieving optimal physical and cognitive sports performance, and are considered to have nootropic characteristics.

For example, magnesium is crucial in ATP synthesis. ATP is the primary energy source for mitochondria in every cell, including those in the brain. ATP must be bound to magnesium in order to be activated. Magnesium combined with B vitamins can help maximize the energy potential. Magnesium joined to creatine has shown to increase work output over individual components and is present in many powder formulations in the market today.* As cognition and active lifestyles gain more awareness, magnesium and beneficial combinations with other nutrients will become more important.

How well does magnesium formulate into the many types of sports nutrition products on the market?

Magnesium has traditionally been supplemented as tablets and capsules, and can still be used in that way. However, magnesium lends itself well in the many sports nutrition applications, including sports drinks, powders, bars, “shots,” and gummies. Selecting the right form of magnesium for the application is important based upon delivery mechanism, other ingredients, and organoleptic properties.

* Editor’s note: Balchem/Albion supplies a magnesium creatine chelate ingredient called Creatine MagnaPower.

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.
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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