The first two approaches that usually come to mind when we want to improve our sports performance are training and nutrition. We know that there are numerous training strategies to enhance performance depending on which ability we want to improve and, essentially, on what our goal is. In today’s article we are going to talk about a micronutrient, zinc, whose intake should be ensured, especially in athletes.
If we are amateurs and our margin for improvement is large, the support of a professional will be extremely helpful to guide our training and achieve the expected results. On the other hand, if we are professionals and our margin for improvement is small, any improvement—no matter how slight—in any of the factors that affect sports performance can be considered a real achievement.
In addition to professional guidance in training, this is where nutrition comes into play, and more specifically micronutrition and dietary supplements.
What happens with zinc in athletes?
One of the most common mistakes is treating athletes as if they were sedentary individuals, and clearly this should not be the case. The differences between these two populations are enormous and should be taken into account. This is why there is a pressing need for research in order to establish specific nutritional recommendations for this population. As shown in the results of a meta-analysis, one example of these differences in micronutrient demands and requirements is zinc. This meta-analysis showed that blood zinc levels were lower in athletes compared to the control group, despite a higher zinc intake.
Zinc is a mineral involved in energy metabolism, immunity and antioxidant systems. In muscle tissue, most zinc is found as part of protein complexes, providing stability and contributing to the activity of certain enzymes such as lactate dehydrogenase and superoxide dismutase.
Due to these functions, low zinc levels are considered to be associated with reduced cardiorespiratory function and therefore a decrease in aerobic exercise performance.
It appears that zinc intake and maintaining levels within the normal range may be associated with an improvement in VO2max and a reduction in blood viscosity, which could enhance aerobic performance, although the true impact of zinc on sports performance is still not entirely clear.
What about zinc losses?
In addition to the functions mentioned above, there is evidence of zinc loss through sweat and urine during and after exercise, highlighting why athletes’ zinc requirements are higher than those of sedentary individuals.
Furthermore, within the athletic population, special attention should be paid to vegan and vegetarian athletes and their zinc requirements. This group, not only because they are athletes but also due to their dietary pattern, may require higher amounts of this micronutrient. This is because a well-designed vegan diet rich in fibre—such as one with a high intake of legumes, fruits, vegetables and whole grains—provides higher amounts of phytates and/or calcium, which can partially reduce zinc absorption.
What are the causes and consequences of zinc deficiency?
For zinc to be transported through the body’s cells to the organs where it exerts its effects, it requires specific transporters.
Da Rocha et al. concluded that blood zinc levels were lower in individuals with genetic variants in genes related to zinc transporters in the body. Therefore, people with these genetic variants will have higher zinc requirements.
If zinc intake comes from food sources such as rice, spinach, oats, pumpkin seeds, milk or seafood, there is generally no issue with excess zinc. However, supplementation should always be supervised by a professional. As with other minerals and nutrients, zinc deficiency may result in delayed growth in children, weight loss, increased susceptibility to infections, reduced night vision, slower wound healing, reduced regenerative capacity, progressive loss of taste and smell, and even skin lesions, scaly skin and white spots on the nails. It is safe to say that zinc deficiency would be counterproductive for overall sports performance, as it would impair muscle regeneration capacity and lead to feelings of weakness.
Given the essential role of this mineral both in daily life and in sport, the most advisable approach is always to consult a professional who can assess and estimate zinc requirements based on individual context, lifestyle and athletic needs.
References
Chu A, Petocz P, Samman S. Immediate Effects of Aerobic Exercise on Plasma/Serum Zinc Levels: A Meta-analysis. Med Sci Sports Exerc. 2016;48(4):726–733. doi:10.1249/MSS.0000000000000805
Anderson RA, Bryden NA, Polansky MM, Deuster PA. Acute exercise effects on urinary losses and serum concentrations of copper and zinc of moderately trained and untrained men consuming a controlled diet. Analyst. 1995;120(3):867–870. doi:10.1039/an9952000867
Jakše B. Placing a Well-Designed Vegan Diet for Slovenes. Nutrients. 2021;13(12):4545. doi:10.3390/nu13124545
Khaled S, Brun JF, Cassanas G, Bardet L, Orsetti A. Effects of zinc supplementation on blood rheology during exercise. Clin Hemorheol Microcirc. 1999;20(1):1–10.
Supplementation in Exercise and Athletic Performance: A Systematic Review. Nutrients. 2019;11(3):696. doi:10.3390/nu11030696
Day KJ, Adamski MM, Dordevic AL, Murgia C. Genetic Variations as Modifying Factors to Dietary Zinc Requirements—A Systematic Review. Nutrients. 2017;9(2):148. doi:10.3390/nu9020148
