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ABSTRACT: Magnesium is an essential element that regulates membrane stability and neuromuscular, cardiovascular, immune, and hormonal functions and is a critical cofactor in many metabolic reactions. The Dietary Reference Intake for magnesium for adults is 310 to 420 mg/day. However, the intake of magnesium in humans is often suboptimal. Magnesium deficiency may lead to changes in gastrointestinal, cardiovascular, and neuromuscular function. Physical exercise may deplete magnesium, which, together with a marginal dietary magnesium intake, may impair energy metabolism efficiency and the capacity for physical work. Magnesium assessment has been a challenge because of the absence of an accurate and convenient assessment method. Recently, magnesium has been touted as an agent for increasing athletic performance. This article reviews the various studies that have been conducted to investigate the relationship of magnesium and exercise.
I. INTRODUCTION
Magnesium is an essential mineral and a cofactor for over 325 enzymatic reactions involved in cellular energy production and storage, protein synthesis, deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) synthesis, cell growth and reproduction, adenylate cyclase synthesis, maintenance of cellular electrolyte composition, and stabilization of mitochondrial membranes.1 Magnesium plays a central role in the control of neuronal activity, cardiac excitability, neuromuscular transmission, muscular contraction, vasomotor tone, and blood pressure.1 Therefore, magnesium deficiency may lead to changes in gastrointestinal, cardiovascular, and neuromuscular function.I The magnesium intake of the general population may be suboptimal and, consequently, athletes may also be consuming inadequate amounts of magnesium.2,3 Exercise is a potent stressor that appears to lead to magnesium depletion through alterations in blood magnesium levels as well as increased excretion through sweat and urine, and may compound a state of deficiency when magnesium intake is inadequate. Research has shown that magnesium deficiency may reduce physical performance and magnesium status may have an effect on exercise capacity. During the last decade there has been considerable interest in whether mineral supplementation can result in an improvement in athletic performance. Therefore, the aim of this review is to assess whether physical activity is a factor leading to a magnesium deficit, to determine the consequences of magnesium deficit in the pathophysiology of sport, and discuss the effects of magnesium supplementation on physical performance.2,3 Prior to the discussion of magnesium and exercise, a comprehensive review of the chemistry, metabolism,...