Zinc in an athlete’s diet – supporting recovery and performance

For many years, sports nutrition was primarily discussed in terms of energy, protein, hydration and meals consumed around training sessions. Over time, increasing attention began to be paid to minerals as well, as exemplified by research in the early 1990s into zinc loss through sweat during exercise under various temperature conditions. In 1993, such an experiment was described involving athletes who exercised on a cycle ergometer, after which sweat samples were analysed for zinc content.

1. Characteristics of zinc
2. Zinc in sport
3. Zinc in the diet and supplements

Characteristics of zinc

Zinc is a mineral element present in many tissues and bodily fluids. In the body, it plays a role in the functioning of numerous enzymes and regulatory proteins, and is therefore involved in cellular processes at various levels. One of the key areas of its function is the proper synthesis of deoxyribonucleic acid, or DNA, which carries genetic information and must be replicated in cells undergoing natural renewal.

Zinc also aids in the proper synthesis of proteins, many of which serve as essential structural and functional building blocks of the body. Proteins form enzymes (which synthesise and break down substances), receptors and transporters (which influence cellular communication), and structural components of cells. Additionally, zinc is also involved in the process of cell division. This is one of the fundamental mechanisms associated with the renewal and maintenance of tissue structure and the entire body.

Zinc in sport

In an athlete’s diet, zinc is important primarily because regular physical exercise involves repeated strain on the muscles, tendons, ligaments and other tissues involved in movement. After training, the body requires a sufficiently high intake of energy (calories), amino acids (and proteins), vitamins and minerals to maintain the proper functioning of basic physiological processes.

Zinc fits into this context as a component that aids in proper protein synthesis. This is important both in strength sports, where there is a strong emphasis on short-term but intense muscle work under heavy loads, and in endurance disciplines, where prolonged exertion necessitates constant tissue regeneration and metabolic balance.

Estimated zinc content in foods frequently chosen by athletes

Zinc in the diet and supplements

Meeting your zinc requirements is no substitute for sleep, rest, an adequate protein intake or a proper training plan, but it is one component of a well-balanced diet for a physically active person. The importance of zinc can be particularly evident when the diet is low in energy, monotonous, restrictive, or excludes foods naturally rich in this mineral.

Zinc can be obtained from both animal and plant sources, though its content and bioavailability depend on the type of food and the overall composition of the diet. Sources of animal origin include primarily meat, offal, fish, seafood, eggs and dairy products. Among plant-based products, it is worth mentioning pumpkin seeds, sunflower seeds, sesame seeds, nuts, whole grain cereal products, groats and pulses.

"Our bodies need a range of nutrients, including minerals, to support essential health functions. One of these is zinc, which plays a key role in many of the body’s processes." Agata Bugorska – Dietitian

In diets based mainly on plant-based foods, the presence of phytates is significant; these are found in cereals, pulses, nuts and seeds, amongst other things, and can limit the absorption of zinc. For this reason, the same zinc content in different foods does not always result in the same bioavailability for the body.

The Reference Intake (RI) for zinc is 10 mg and is the value used in the labelling of food and supplements. Zinc supplements usually contain between a few and several milligrams of zinc per serving, typically in the form of gluconate, citrate, picolinate, lactate or oxide. Supplementation can be part of a dietary regimen, particularly when the daily diet does not provide adequate amounts of zinc, but the foundation remains a well-planned diet based on a variety of foods.

Sources:

• Tipton, K., Green, N. R., Haymes, E. M., & Waller, M. (1993). Zinc loss in sweat of athletes exercising in hot and neutral temperatures. International journal of sport nutrition, 3(3), 261–271. https://doi.org/10.1123/ijsn.3.3.261
• Beyersmann, D., & Haase, H. (2001). Functions of zinc in signaling, proliferation and differentiation of mammalian cells. Biometals : an international journal on the role of metal ions in biology, biochemistry, and medicine, 14(3-4), 331–341. https://doi.org/10.1023/a:1012905406548
• Chu, A., Holdaway, C., Varma, T., Petocz, P., & Samman, S. (2018). Lower Serum Zinc Concentration Despite Higher Dietary Zinc Intake in Athletes: A Systematic Review and Meta-analysis. Sports medicine (Auckland, N.Z.), 48(2), 327–336. https://doi.org/10.1007/s40279-017-0818-8