Tuesday, April 28, 2009

Minerals and Sport Performance an overview

Minerals are very important for every athlete. They are part of muscle contraction, oxygen transport, help in nerve impulse conduction and acid-base balance of the blood, support a healthy immune system, have antioxidative properties…Which minerals are from outmost importance, which minerals have an ergogenic effect and does it make sense to supplement with minerals?
An athlete generally should try to achieve adequate mineral intake through their daily diet without extra supplementation in the first attempt. If an athlete is deficient in a mineral, supplementation might improve bodily function and therefore performance. The two most deficiencies in athletes are known to be calcium and iron.

Overview:

Calcium is stored in the skeletal system and helps in muscular contraction. Calcium need is increased in athletes, especially with high intensity training. Insufficient calcium intake will lead to decreased bone density. (Females more likely to develop calcium deficiency) Additional calcium intake if athlete is not deficient does not enhance performance.

Phosphorus helps in energy metabolism. Phosphate salt supplementation resulted in equivocal results in different study. Some studies reported a lower RPE and therefore a beneficial psychological effect of Phosphate supplementation before exercise.

Magnesium regulates muscle contraction, oxygen delivery and helps in protein synthesis. Studies have not shown improvements in performance with supplementation.

Iron is important for oxygen transport. Iron supplementation should improve performance in deficient individuals but will not have an effect in people with no deficiency. Iron losses include sweat losses, menstrual, gastrointestinal losses or myoglobin leakage. Iron supplementation has also proved to be beneficial for athletes training in altitude to stimulate EPO production.

Zinc deficiency is seen in individuals with a high carb, low protein diet. Constant fatigue, loss of body weight and decreased endurance performance are among symptoms of zinc deficiency. General supplementation is not recommended.

Chromium, an insulin cofactor, might have an ergogenic effect by facilitating BCAA transport into the muscle. In general studies have failed to show effects on sport performance with chromium supplementation.

Vanadium also helps to enhance insulin activity whereas the limited data available does not support an anabolic effect if individual is healthy.

Selenium supplementation has shown in some studies to enhance gluthatione peroxidase status in aerobic exercise. Whereas the studies failed to show improvements in performance.

Conclusion:

After reviewing minerals, there is no effidence of any mineral to enhance performance. If an athlete has a well balanced diet, he should be able to meet almost all of his mineral needs. Athletes who are deficient of a mineral might improve performance and bodily function with supplementation. As a female runner, I have constantly problems to keep my iron levels up. Supplementation has helped me to improve performance. But negatively, constant supplementation might have adverse effects. Therefore an athlete should research what foods contain the mineral he is in need of.

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