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The aim of this study was to determine the possible changes in plasma of several hormones such as Luteinizing Hormone, Testosterone, Cortisol and Insulin in endurance runners during the sports season. Twenty-one high-level male endurance runners (22 ± 3.2 years, 1.77 ± 0.05 m) participated in the study. Basal plasma hormones were measured at four moments during the season (initial, 3, 6 and 9 months), and were analyzed using ELISA (enzyme-linked immunosorbent assay). Testosterone and Luteinizing Hormone (LH) suffered very significant decreases ( p < 0.01) at 3 months compared with the beginning and an increase ( p < 0.05) at 6 and 9 months compared with 3 months. Insulin level was significantly lower ( p < 0.05) at 3, 6 and 9 months compared with the initial test. Insulin and cortisol were associated inversely (r = 0.363; β = -0.577; p = 0.017) and positively (r = 0.202; β = 0.310; p = 0.043), respectively, with the amount of km per week performed by the runners. There was a significant association between km covered at a higher intensity than the anaerobic threshold and I (r = 0.580; β = -0.442; p = 0.000). Our findings indicate that testosterone, LH and insulin were more sensitive to changes in training volume and intensity than cortisol in high-level endurance runners. Basal testosterone and LH concentrations decrease in athletes who perform a high volume of aerobic km in situations of low energy availability.

The aim of the present study was to determine changes occurring in serum and urine concentrations of essential trace elements with proven essentiality (molybdenum, selenium, and zinc) as a result of performing an acute physical activity until exhaustion in middle- and long-distance runners who live in the same area of Extremadura (Spain). Twenty-one Spanish national middle- and long-distance runners and 26 sedentary students of a similar age were recruited for the study. Both groups ran on a treadmill until exhaustion, starting at a speed of 10 and 8 km/h, respectively, and increasing the speed at 1 km/h every 400 m, without modifying the slope, always within the recommended parameters. Serum and urine samples were obtained from all subjects before and after the tests. Analysis of trace metals was performed by inductively coupled plasma mass spectrometry (ICP-MS). Resting serum and urinary concentrations between groups were compared using the Student t test, and the Wilcoxon test was used to analyze the trends of changes before and after the effort. The results showed that molybdenum concentrations were significantly higher in athletes than in controls (p < 0.01). Selenium (p < 0.05) and zinc (p < 0.01) concentrations were significantly lower in athletes than in controls. When we compared the serum concentrations before and after the test in the controls, only in the case of selenium (p = 0.006), a significant increase was observed after the test. However, this signification disappears with the corrections for hematocrit. Athletes' serum concentrations of Se (p = 0.004) and Zn (p = 0.005) lowered at the end of the test. Also, the results showed that there were no statistical urinary concentration (expressed in μg/g creatinine) changes in Mo and Se. Zn urinary concentration increased at the end of exercise (p = 0.018), since an incremental exercise to exhaustion in middle- and long-distance elite athletes produces a decrease in Se and Zn serum concentrations but Zn urinary concentration increased. In conclusion, athletes show higher serum concentrations of molybdenum and lower serum concentrations of selenium and zinc than sedentary subjects. Additionally, a treadmill test until exhaustion provokes a decrease in serum concentration of selenium and zinc and a higher excretion of urinary zinc. Serum concentrations of Se and Zn should be carried out in order to avoid any possible deficit cases and to establish the optimal supplementation.

Background: The aim of the present study was to determine changes in the serum concentrations of trace elements Cobalt (Co), Molybdenum (Mo) and Zinc (Zn) among high-level sportsmen. Methods: Eighty professional athletes of different metabolic modalities (aerobic, anaerobic and aerobic-anaerobic), were recruited before the beginning of their training seasons. Thirty-one sedentary participants of the same geographic area constituted the control group. Co, Mo and Zn analysis was performed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Results: Serum concentration of Mo (p < 0.001) was higher among sportsmen compared to the control group values. Separated by modalities, the concentrations of Co in the aerobic-anaerobic athletes were lower (p < 0.01) than in the control group as well as than in the other athletes. The highest Mo concentration was found in anaerobic sportsmen (p < 0.001), followed by aerobic-anaerobic (p < 0.001) being both statistically higher in comparison with the control group. In relation to Zn, it was observed that aerobic-anaerobic (p < 0.001) and anaerobic (p < 0.001) sportsmen showed higher concentrations than the control participants. However, aerobic sportsmen showed lower concentrations (p < 0.01) than controls. Conclusion: This data manifest that long-term, daily physical training may induce variations in serum concentrations of several essential elements among sportsmen in comparison to untrained men and that these changes seems to be related to the sports modality practiced. [ABSTRACT FROM AUTHOR]

Background: The aim of the present study was to determine changes in serum concentrations of trace elements Cooper (Cu), Chromiun (Cr), Manganesum (Mn), Nickel (Ni) and Selenium (Se) in high-level sportsmen. Methods: Eighty professional athletes of different metabolic modalities, were recruited before the start of their training period. Thirty one sedentary participants of the same geographic area constituted the control group. Cu, Cr, Mn, Ni and Se analysis was performed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Results: Higher concentrations of Cr (p < 0.001), Mn (p < 0.085), and Ni (p < 0.001) were found in sportsmen in comparison to controls, inversely, Se values were lower (p < 0.001) among sportsmen. When sportsmen were classified by metabolic modalities, it was found that aerobic-anaerobic group had higher (p < 0.01) Cu concentrations than controls and the other sportsmen. The highest Cr values were found in aerobic participants. For Mn, the major levels were found in aerobic and aerobic-anaerobic groups as well (p < 0.001). The lowest Se levels were found among anaerobic sportsmen (p < 0.001). Conclusion: This research showed that daily, continuum physical training induced alterations in serum essential minerals concentrations, as well as that these changes can be dependent of the exercise modality practiced. [ABSTRACT FROM AUTHOR]

An amendment to this paper has been published and can be accessed via the original article. [ABSTRACT FROM AUTHOR]