Overtraining does not induce oxidative stress and inflammation in blood and heart of rats.

The aim of our research was to evaluate the changes in levels of cytokines and redox state parameters in blood and isolated heart of rats subjected to different swimming protocols. Rats were divided into 3 groups: 1) controls, 2) moderately trained rats that during all 12 weeks swam 1 h/day, 5 days/week, and 3) overtrained rats that in 10(th) week swam twice, 11(th) week 3 times, and in 12(th) week 4 times a day for 1 h. After sacrificing, blood from jugular vein was collected, and the heart excised and perfused on a Langendorff apparatus. Samples of the coronary effluent were collected during coronary autoregulation. Levels of superoxide anion radical (O(2)(-)), hydrogen peroxide (H(2)O(2)), nitric oxide (NO) and thiobarbituric acid reactive substances (TBARS) were measured in plasma and coronary effluent, while reduced glutathione (GSH), activities of superoxide dismutase (SOD) and catalase (CAT) were measured in erythrocytes. Venous blood was also used for interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-alpha) determination. Moderate training protocol induced the decrease of TBARS in plasma, while both training protocols induced the decrease of O(2)(-) and H(2)O(2) in coronary effluent. There was no significant difference in levels of cytokines between groups. The results of study add evidence about beneficial effects of moderate-intensity training on blood and cardiac redox state of rats, and furthermore, shows that exercising frequently, if the intensity stays within moderate range, may not have detrimental effects.

Indicators of iron status in elite soccer players during the sports season.

The main aim of the study was to investigate the changes of hematologic status in elite soccer players throughout a competitive season. Study was conducted with 35 male professional soccer players and the measurements were collected at the start of the conditioning period, at the start of the season, in the mid-season and at the end of the season. Blood was drawn from an antecubital vein for a complete blood count, serum iron, and transferrin and ferritin levels. We found significantly higher hematocrit at preseason assessment as compared with other sampling periods (P < 0.05). No other differences were found between any of the hematologic variables during the study. The lowest hemoglobin level, mean corpuscular volume (MCV), serum iron, ferritin and transferrin encountered in the study were Hb of 11.2 g/dl, MCV of 77.9 fl, serum iron of 34 microg/dl, ferritin of 15.1 microg/l, transferrin of 224 microg/dl in a 20-year-old soccer player at the start of the season. The variability of the iron status indicators in elite soccer players seems to be stable and poorly related to training phase during sports season.

Weekly training volume and hematological status in female top-level athletes of different sports.

AIM: The objectives of the present study were: a) to investigate the prevalence of iron depletion and anemia among female top-level athletes from different sports; b) to determine a relationship between serum ferritin levels and training status of female athletes. METHODS: This study was conducted on 84 female professional athletes who were recruited during preparticipation physical examination. Upon entering the laboratory 10 mL of venous blood was drawn from an antecubital vein into a lavender-top tube for a complete blood count (CBC), serum iron, and transferrin and ferritin levels. RESULTS: No significant differences between any of the hematological variables were found between groups of different sports. The lowest hemoglobin (Hb), mean corpuscular volume (MCV), serum iron, ferritin and transferrin encountered in the study were Hb of 9.1 g/dL, MCV of 64.5 fL, serum iron of 15 microg/dL, ferritin of 5.4 microg/L, transferrin of 210 microg/dL in a 20-year old female distance runner with functional impairment and iron deficiency anemia. No significant differences were found between female athletes from different sports regarding the prevalence of iron depletion, iron deficiency or iron deficiency anemia (IDA). Serum ferritin level poorly correlate with training duration (r = 0.24) and seems to be inadequate indicator of training tolerance. CONCLUSION: This study has shown a high prevalence of iron depletion and anemia among female athletes from different sports, with similar incidence in individuals independent of their weekly training volume.