title: [Seasonal alterations in serum iron levels in elite football players].
abstract: BACKGROUND
  It is very important to monitor levels of serum iron and other factors of iron metabolism and oxygen transport system as they play a very important role in functional ability of football players. A decrease in serum iron level can be the very first sign of development of iron deficiency anaemia, which seriously influences health and functional ability of an athlete and is a common problem in competitive sports.
  
  
  OBJECTIVE
  The aim of this study was to observe and evaluate changes in serum iron values during the competition season in relation to the training process.
  
  
  METHODS
  During four years, serum iron level was measured in 28-34 players of one of the top football clubs in Serbia, four times a year: at the beginning and at peak-point of both half-seasons. Differences between basic and control findings, relative and absolute changes in serum iron levels and statistical significance of the findings were than calculated.
  
  
  RESULTS
  There was a significant decrease in mean serum iron levels on each control test, compared to basic values. Mean value of control serum iron levels is significantly lower than mean of preseason values (20.64 +/- 6.58 vs. 16.38 +/- 5.51 micromol/l).
  
  
  CONCLUSIONS
  A significant decrease in serum iron level among footballers during both half-seasons is most probably due to an increased loss and/or diminished absorption resulting from a high intensity training process. Because the decline in serum iron may be an early sign of iron store depletion and iron deficiency anaemia, it is very important to evaluate it regularly, along with other factors of iron metabolism and oxygen transport system.
authors.forename: Sead
authors.initials: S
authors.lastname: Malićević
authors.forename: Dejan
authors.initials: D
authors.lastname: Nesić
authors.forename: Ilija
authors.initials: I
authors.lastname: Rosić
mesh_terms: D000293:Adolescent; D000328:Adult; D006801:Humans; D007501:Iron / Q000097:blood*; D008297:Male; D012621:Seasons; D012916:Soccer / Q000502:physiology*; D055815:Young Adult
chemical_list: D007501:Iron