“Little things make big things happen.” It seems that there is evidence for this quote in all walks of life, include athletic performance and nutrition. Recently, scientific investigators have reported that up to 60% of female athletes and 25% of male athletes are considered to be deficient in an important micronutrient involved in the process of oxygen consumption and aerobic exercise performance. Interestingly, even with proper monitoring and treatment regarding dietary intake, deficiencies of this particular trace mineral were still noted in athletes (Coates, Mountjoy& Burr, 2017). It’s hard to imagine that a deficiency in an element needed in just minute quantities, can play such a vital role in disrupting the integrity of various physiological and metabolic processes fundamental for athletic function and success. Furthermore, performance specialists tasked with the major responsibility of driving athletic potential can also miss this little detail in dietary needs. But alas, little things make big things happen, and safeguarding your athlete’s potential through routine dietary screening and supplementation can be the little change for a big difference. Evaluating the level of micronutrients such as iron and magnesium should be part of a comprehensive approach in your performance system, to help diminish the potential obstacles in your athlete’s ability. Adopting such an approach also adds a measure for safety by providing insight into potential excess of both essential and toxic elements. Take for instance the micronutrient iron.
Iron is widely recognized for its significant impact to health and performance in elite athletes and its deficiency can have a number of negative impacts on various physical capabilities such as aerobic performance. This relationship of iron to performance largely stems from its critical role in forming an important oxygen transporting protein known as hemogloblin. Thus, a deficiency in iron, and/or the presence of iron deficiency anemia is likely to diminish levels of hemoglobin, resulting in impaired performance due to the limited ability of oxygen to be transported to muscle tissue (Roland, 2011). Authors have also noted that factors involved in athletic performance such as increased fatigue levels and decreased energy drive are also resulting symptoms of low levels of iron (Eichner, 2012). Moreover, insufficient levels of iron can negatively impact immune system function and diminish bone strength.
This relationship between iron and various measures of physical function is testament to the powerful impact of such minute minerals, otherwise known as inorganic substances essential for metabolic and/or structural functions in the body. Many factors fundamental to athletic performance are manifested through the optimal function of processes within the body therefore we must consider optimizing micronutrient intake of our athletes. While macronutrients such as carbohydrates, fats and proteins play a valuable role and are often touted for their powerful contributions to factors related to physical function and performance, micronutrients must also be largely recognized.
Similarly to iron, the micronutrient magnesium has also been demonstrated to have a monumental impact to athletic performance through the efforts of researchers. For instance, researchers at the University of São Paulo showed that supplementation with magnesium contributed to positive markers of athleticism such as decreases in lactate production and significant increases in jumping capabilities (Setaro et al., 2014). Investigators in this study concluded that supplementation with magnesium resulted in improvements in anaerobic function despite no evidence of magnesium deficiencies in the athletic subjects. This should come as little surprise as magnesium is involved in a number of critical roles necessary for human function. Minute amounts of the trace mineral magnesium is needed for its role in enzymatic reactions, cell growth, and energy metabolism, such as glycolysis and protein synthesis (Zhang, Xun, Wang, Mao & He, 2017. Magnesium is believed to positively impact athletic performance through its ability to regulate the concentration of glucose and lactate in the brain, muscle, and in circulation (Zhang, Xun, Wang, Mao & He, 2017). A number of animal and human studies have demonstrated improvements in various factors related to increased performance with magnesium supplementation such as, increased strength, enhanced glucose utilization, delayed muscle fatigue through the attenuation of muscle lactate, and improved muscle recovery through increased levels of glucose post exercise (Lee, 2017; Zhang, Xun, Wang, Mao & He, 2017). Conversely, authors note that when magnesium is depleted from the diet, there are notable adverse effects to metabolism, cardiovascular function and exercise performance (Lee, 2017). Despite the critical role of magnesium to human function and performance deficiencies have been noted in a number of athletic populations.
A 2017 study published in the Journal of Magnesium research reported that existing data demonstrates that most athletes do not consume adequate amounts of magnesium in their diets (Alfredo, Diego, Juan, Jesús, & Alberto, 2017). Additionally, investigators of a 2009 study published in the Journal of Clinical nutrition, determined that international female and male collegiate soccer players, as well as male rugby players, fell below the proper required amount of magnesium in their diets (Noda et al., 2009). This finding was suggested by investigators to be a representation of dietary deficiencies characteristically found in collegiate athletes. In addition, previous studies have reflected an intake as low as 45% of the daily recommended amount in elite athletes suggesting that magnesium deficiencies are evident even at the highest level of athletics.
Similar to magnesium, iron has long been established as a mineral often deficient in athletic populations. Dr. Thomas Rowland notes in a review titled: Iron deficiency in athletes: An update that a high frequency of iron deficiency without anemia, has been consistently observed in trained athletes, particularly female runners. While not a common finding in male athletes, Rowland notes that in any group of training endurance athletes, 1 out of every 3 or 4 females can be expected to satisfy the criteria for nonanemic iron deficiency (Rowland, 2012).
Growing research supports iron and magnesium as not only essential minerals to both human function and athletic performance, but also as minerals likely to be reported deficient in athletes. These minerals are clear examples of dietary factors in which performance and/or dietary specialists must carefully monitor when attempting to mediate improvements in their athlete’s potential. Failure to acknowledge these factors during periods of competiton can result in diminished performance but can also negatively impact health and human function.
As performance specialists we should consistently encourage our athletes to be routinely screened for mineral deficiencies and to be mindful of the role in which their diet and nutritional requirements can help facilitate greater levels of potential and performance. Effective approaches for deficiencies can take place through both dietary means and supplementation but before those changes can take place we have to assess our athlete’s needs. Screening resources such as Blueprint for Athletes can play a powerful role in the evaluation and treatment of athletic performance. In addition to Blueprint for Athletes, there are a number of affordable and reliable nutrition screening services available online to help provide insight to iron indicators such as serum ferritin.
This iron indicator has been noted to be substantially different in highly trained athletes as compared to the normal population (Chapman et al., 2017). Serum ferritin values of 20 ng·mL−1 are commonly recognized as a low range for iron and an indication of deficiency in normal populations however new data suggests that such a value may be too low for athletes. New research suggests that a lower range for serum ferritin criterion value in athletes should be set at 35 ng·mL−1 . This range may demonstrate that a far greater amount of both male and female athletes are iron deficient (Chapman et al., 2017).
Additionally, magnesium is often measured by serum concentration. A reference range of 0.65–1.05 mmol/L for total magnesium concentrations in adult blood serum is considered to be healthy physiological range (Jahnen-Dechent, & Ketteler, 2012).
While there are a number of minerals that are essential to diet and function, research continues to support an important role of magnesium and iron. It’s important to note that while these minerals are important for function excess intake of these minerals can lead to adverse effects and should be avoided. For instance, iron excess may be pro-oxidative and has been linked to several chronic diseases.
As we continue to develop further in to the science of sports performance and in light of the growing measures of assessments available to athletes, we may find that it’s miniscule actions such as monitoring the level of little factors such as trace minerals that may be imperative to the big picture or great athletic success.
Alfredo,C., Diego, F., Juan, M., Jesús, S., Alberto, C.G., (2017) Effect of magnesium supplementation on muscular damage markers in basketball players during a full season. Journal of Magnesium Research. 30(2), 61-70.
Chapman, R. F., Sinex, J., Wilber, R., Kendig, A., Moreau, B., Nabhan, D., & Stray-Gundersen, J. (2017). Routine Screening for Iron Deficiency Is an Important Component of Athlete Care. Medicine & Science in Sports & Exercise, 49(11), 2364.
Noda, Y., Iide, K., Masuda, R., Kishida, R., & Nagata, A., & Hirakawa, F.,Yoshimura, Y., Imamura, H. (2009). Nutrient intake and blood iron status of male collegiate soccer players. Asia Pacific Journal of Clinical Nutrition. 18, 344-350.
Setaro L, Santos-Silva PR, Nakano EY, et al. (2014). Magnesium status and the physical performance of volleyball players: effects of magnesium supplementation. Journal of Sports Science 32(5), 438–445.