Analysis of Intracellular and Extracellular Selenium Concentrations: Differences According to Training Level

Plasma, Urinary, Erythrocyte and Platelet Zinc Concentrations in Soccer Players

Essential trace minerals are vital for general human health and athletic performance. Zinc (Zn) plays critical roles in several biochemical processes in exercise physiology, especially during intense physical exercise. This research aimed to analyze erythrocyte, platelet, plasma and urine Zn concentrations among men's and female soccer players over a sports season. A total of 22 male soccer players (20.61 ± 2.66 years; 71.50 ± 5.93 kg) and 24 female soccer players (23.37 ± 3.95 years; 59.58 ± 7.17 kg) participated in this longitudinal quasi-experimental study. Three assessments were carried out over the season: 1st evaluation: first week of training (August); 2nd assessment: middle of the season, between the end of the first and second round (January) and 3rd assessment: last week of training (May/June). In all evaluations extracellular (plasma and urine) and intracellular (erythrocytes and platelets) Zn concentrations were determined, as well as physical fitness and several blood parameters. Inductively coupled plasma mass spectrometry was used to measure Zn concentrations. Plasma and urinary concentrations were higher among male soccer players (p < 0.05) while erythrocyte and platelet Zn concentrations were higher in the female soccer players (p < 0.05). Additionally, variations in urinary and platelet Zn concentrations were observed over the season. The differences could be related to muscle mass, muscle damage or the specific sport's physical demands.

Total Iron Concentrations in Different Biological Matrices-Influence of Physical Training

Iron (Fe) is one of the most widely studied trace mineral elements. Fe metabolism and homeostasis could be altered by physical training. The aim of this study was to analyze the influence of long-term physical training on serum, plasma, urine (extracellular), erythrocyte and platelet (intracellular) Fe concentrations. Forty men from the same geographical area divided into a training group (TG; n = 20; 18.15 ± 0.27 years) and a control group (CG; n = 20; 19.25 ± 0.39 years) participated in this study. The TG was composed of soccer players of the highest youth category. The CG consisted of young people who did not follow any training routine and had not practiced any sport for at least the previous six months. The TG showed higher plasma and serum Fe concentrations (p < 0.05), but lower concentrations in erythrocytes and platelets compared to the CG (p < 0.01). Due to the differences observed in the extracellular and intracellular compartments, it seems necessary to perform a global Fe analysis to assess Fe status.