title: Is iron treatment beneficial in, iron-deficient but non-anaemic (IDNA) endurance athletes? A systematic review and meta-analysis.
abstract: OBJECTIVE
  The aim of this study was to determine whether iron treatments improve the iron status and aerobic capacity of iron deficient non-anaemic endurance athletes.
  
  
  METHODS
  A meta-analysis of studies that investigated the effects of iron treatment on serum ferritin (sFer), serum iron (sFe), transferrin saturation (Tsat), haemoglobin concentration ([Hb]) and (VO(2max)). Seventeen eligible studies were identified from online databases.
  
  
  RESULTS
  Analysis of pooled data indicated that iron treatments had a large effect on improving sFer (Hedges' g=1.088, 95% CI 0.914 to 1.263, p<0.001), sFe (Hedges' g=1.004, 95% CI 0.828 to 1.181, p<0.001) and Tsat (Hedges g=0.741, 95% CI 0.564 to 0.919, p<0.001) and a moderate effect on improving [Hb] (Hedges' g=0.695, 95% CI 0.533 to 0.836, p<0.001) and (VO(2max)) (Hedges' g=0.610, 95% CI 0.399 to 0.821, p<0.001). Regression analysis revealed a significant interaction between the effect of iron treatment on sFer and treatment duration, suggesting treatments that lasted beyond 80 days appear to have the least effect on sFer.
  
  
  CONCLUSIONS
  These results indicate iron treatments improve the iron status and aerobic capacity of iron deficient non-anaemic endurance athletes.
authors.affiliation: Centre for Health, Applied Sport and Exercise Science, St. Mary's University, Twickenham, UK.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Burden
authors.affiliation: Centre for Health, Applied Sport and Exercise Science, St. Mary's University, Twickenham, UK.
authors.forename: Katie
authors.initials: K
authors.lastname: Morton
authors.affiliation: Division of Surgery, University College London, London, UK.
authors.forename: Toby
authors.initials: T
authors.lastname: Richards
authors.affiliation: Research Institute for Sport and Exercise Science, Liverpool John Moores University, Liverpool, UK.
authors.forename: Gregory P
authors.initials: GP
authors.lastname: Whyte
authors.affiliation: Centre for Health, Applied Sport and Exercise Science, St. Mary's University, Twickenham, UK.
authors.forename: Charles R
authors.initials: CR
authors.lastname: Pedlar
mesh_terms: D054874:Athletic Performance / Q000502:physiology; D004333:Drug Administration Routes; D005260:Female; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D007501:Iron / Q000008:administration & dosage; D000090463:Iron Deficiencies; D008297:Male; D010807:Physical Endurance / Q000502:physiology*; D012044:Regression Analysis; D016896:Treatment Outcome
chemical_list: D006454:Hemoglobins; D007501:Iron
keywords: Aerobic fitness; Anaemia; Endurance; Iron metabolism; Running