Erythrocyte concentrations of chromium, copper, manganese, molybdenum, selenium and zinc in subjects with different physical training levels.

BACKGROUND: The aim of the present study was to determine changes occurring in the erythrocyte concentrations of chromium (Cr), copper (Cu), manganese (Mn), molybdenum (Mo), selenium (Se) and zinc (Zn) in male subjects with different training levels living in the same region (Spain). METHODS: Thirty sedentary subjects (24.34 ± 3.02 years) formed the control group (CG); 24 moderately trained (4-7 h/week) subjects (23.53 ± 1.85 years) formed the group with a moderate degree of training (MTG) and 22 professional cyclists (23.29 ± 2.73 years), who performed more than 20 h/week of training, formed the high-level training group (HTG). Erythrocyte samples were collected from all subjects in fasting conditions, washed and frozen at - 80 °C until analysis. Erythrocyte analysis of trace elements was performed by inductively coupled plasma mass spectrometry (ICP-MS). RESULTS: The results showed that there was a statistically significant lower erythrocyte concentration of Cu, Mn, Mo and Zn in the MTG and HTG than CG. Se was only significantly lower in HTG than CG. The correlation analysis indicates that this change was correlated with training in the case of Cu, Mn, Se and Zn. All results are expressed in µg/g Hb. CONCLUSIONS: We can conclude that physical training produces a decrease in erythrocyte concentrations of Cu, Mn, Se and Zn, which can cause a decrement in athletes' performance given the importance of these elements. For this reason, erythrocyte monitoring during the season would seem to be advisable to avoid negative effects on performance.

Influence of a high-temperature programme on serum, urinary and sweat levels of selenium and zinc.

INTRODUCTION: The effect of hyperthermia on the antioxidant system in the human organism is well known. AIM: The objective of this study was to observe the effects of heat on the concentration of Se and Zn, elements related to antioxidant systems. METHODS: Twenty-nine subjects voluntarily participated in this study. They were divided into a control group (CG; n = 14) and an experimental group (EG; n = 15). All of them underwent two incremental tests until exhaustion in normothermia (22 °C, 20-40%RH) and hyperthermia (42 °C, 20-40%RH). EG experienced nine sessions of repeated heat exposure at high temperatures (100 °C, 20%RH) for three weeks (HEHT). After the intervention, the initial measurements were repeated. Urine and blood samples were collected before and after each test. Additionally, sweat samples were collected after tests in hyperthermia. RESULTS: There were no significant changes in serum. An increase in the elimination of Zn and Se in EG was observed in urine after HEHT (p < .05). The elimination of Zn by sweating decreased after HEHT in EG (p < .05). CONCLUSIONS: Exposure to heat at high temperatures increases the urinary excretion of Se and Zn.

Influence of a 6-month physical training program on serum and urinary concentrations of trace metals in middle distance elite runners.

BACKGROUND: The aim of this survey was to determine the effects of an aerobic physical training program of six months duration on the serum and urinary concentrations of essential trace elements among middle distance runners and untrained, non-sportsmen participants. METHODS: 24 well-trained, middle-distance (1500 and 5000 m), aerobic male runners (AG) were recruited at the beginning of their training season and 26 untrained males formed the control group (CG). All participants were from the same region of Spain, and all of them had been living in this area for at least two years. Serum and urine of samples of Cobalt (Co), Copper (Cu), Manganese (Mn), Molybdenum (Mo), Selenium (Se), Vanadium (V) and Zinc (Zn) were obtained at the beginning of the training season, and six months later, from all participants. All samples were analyzed with inductively coupled plasma mass spectrometry (ICP-MS). RESULTS: Two-way ANOVA showed significant differences relative to group effect in serum concentrations of Co, Cu, Mn, Mo, Se and Zn. Attending to time effect, there were differences in Mn (p = 0.003) and Zn (p = 0.001). The group x time interaction revealed differences only in the case of Mn (p = 0.04). In urine, significant differences between group were obtained in Co, Cu, Mn, Se and V. Time effect showed changes in Co, Cy, Mo and Se. Finally, the group and time interaction revealed significant differences in urinary Cu (p = 0.001), Mn (p = 0.01) and Se (p = 0.001). CONCLUSIONS: A six-month aerobic training program for well-trained athletes induced modifications in the body values of several minerals, a fact which may reflect adaptive responses to physical exercise. The obtained data could be interesting for physicians or coaches in order to consider specific modifications in sportsmen's diets as well as to determine specific nutritional supplementation strategies.

Influence of a physical exercise until exhaustion in normothermic and hyperthermic conditions on serum, erythrocyte and urinary concentrations of magnesium and phosphorus.

AIM: The aim of this study was to evaluate the effect of the performance of a maximal exercise test until exhaustion in normothermic and hyperthermic conditions on body concentrations of magnesium (Mg) and phosphorus (P). METHODS: 19 adult males (age: 22.58 ±â€¯1.05 years) performed two maximum incremental exercise tests on a cycloergometer separated by 48 h. The first was performed in normothermia (22 ±â€¯2 °C) and the second in hyperthermic conditions induced with a sauna (42 ±â€¯2 °C). Blood and urine samples were taken before and after each test. RESULTS: The tests in hyperthermia did not produce ergospirometric alterations or a noticeable cardiovascular drift. Serum Mg concentrations underwent a reduction after the stress test in hyperthermia (p > 0.05) but not in normothermia. Nevertheless, urinary and erythrocyte concentrations of Mg, and urinary, erythrocyte and serum concentrations of P did not undergo alterations in either conditions. CONCLUSIONS: It seems that exercise in hyperthermic conditions induces a tissue redistribution of Mg in the body, a fact which was not observed in normothermic conditions.