A well understood (and often celebrated) aspect of human physiology is that people who engage in strenuous physical activity require more carbohydrates, protein, and fat to sustain their energy levels.^1,2 But what about micronutrient needs? That is, do people who engage in strenuous physical exercise (such as endurance athletes and “weekend warriors”) also require more vitamins and minerals to perform and recover optimally?

The answer is yes. Although not as exciting as refueling with the calories from eggs benedict, micronutrients such as vitamin C, the B vitamins, magnesium, and zinc play important roles in energy production, red blood cell synthesis, bone health, and immune function, and muscle reparation—all of which are critical for physical performance.^3,4 Indeed, some studies have shown that magnesium, in particular, is associated with better sports performance.⁵

Magnesium is one of the most commonly lacking micronutrients, with roughly two-thirds of Americans failing to consume the recommended daily intake.⁶ Insufficient magnesium intake among athletes is particularly concerning, given that the high physical demands of training and competition appear to increase magnesium losses. One of the potential consequences of having low magnesium levels as an athlete is increased muscle damage – which will be our primary focus in this article.   

Does the need for magnesium increase with exercise?

Due to the increased production of sweat and urine during training and competition, athletes experience magnesium losses of up to 20% – putting them at a greater risk for magnesium deficiency.⁷ Athletes that are particularly vulnerable to magnesium deficiency include those who cut calories for weight loss purposes, practice restrictive dieting, or fail to consume the daily vitamin and mineral requirements.

Importantly, research suggests that athletes with low magnesium status are not only at an increased risk of muscle damage while exercising; they may also have a reduced ability to recover.^8,9 The next section will cover magnesium’s role in helping to counter the proinflammatory and muscle-damaging effects that exercise may have on the body’s muscles.

Do athletes have higher levels of inflammation and muscle damage?

Moderate exercise places a healthy amount of stress on our body, which in turn causes a temporary increase in inflammation.¹⁰ Although the inflammation caused by exercise is part of the body’s natural response, competitive athletes and people who engage in vigorous athletic training often push themselves too much. While it’s great to “go hard”, it’s important to note that strenuous exercise can lead to chronic inflammation and muscle damage, which can negatively affect recovery, energy levels, and mood.¹¹

Research shows that a low magnesium status may be associated with excessive production of CRP (a protein that is made by your liver and sent into the bloodstream in response to physical damage).¹² Production of CRP is part of the natural immune response to damage, and is not a harmful substance per se; however, it is thought that excessive or chronic production of CRP may negatively affect cellular health.^13,14 Fortunately, recent meta-analysis reports that magnesium supplementation tends to lower CRP levels.¹⁵ Recent trials even suggest that supplementation with magnesium may help safeguard against the muscle damage caused by extensive training and competition.¹⁶

In a recent study (2019) looking at whether magnesium supplementation influences the development of muscle damage in professional cyclists, participants competing in a 21-day cycling race were split into one of two groups—one that received 400 milligrams of magnesium during the 3-week competition, and one that did not. At the end of the race, the athletes that supplemented with magnesium had less muscle damage than the ones who didn’t. As expected, blood magnesium levels decreased for both groups during the race; however, compared to the control group, the athletes that supplemented with magnesium had significantly higher blood-magnesium levels. This trial suggests that having higher blood levels of magnesium during competition may be protective of muscles during vigorous exercise.

Why might insufficient magnesium increase muscle damage?

Based on what we have learned from animal studies, one way that insufficient magnesium can influence muscular health is by causing the immune system to become excessively active. This can, in turn, lead to the overproduction of free radicals.¹⁷ Although having some radical stress and inflammation is good for our muscles – damage can result if free radical levels remain elevated over time.¹⁸

So how much supplemental magnesium should athletes take to help maintain optimal muscular health and performance? Great question. Although more research is needed to establish dosing recommendations for reducing the effects of muscle damage, for now, individuals who are concerned about low magnesium status should consult their personal physician.

Conclusion

In summary, individuals who regularly engage in vigorous physical exercise should pay special attention to their micronutrient needs—particularly their magnesium status. While future research is still needed to confirm magnesium’s beneficial role in sustaining healthy muscles, the findings reviewed here suggest that athletes can optimize physical performance and recovery by maintaining healthy levels of magnesium.