Effect of Intravenous Iron on Aerobic Capacity and Iron Metabolism in Elite Athletes.
OBJECTIVE
Iron-deficient athletes are often treated with long-term, low-dose iron therapy. Such treatments may be efficacious in correcting iron deficiency; however, the effect on acute and chronic iron metabolism and subsequent endurance capacity is less clear.


METHODS
Fifteen national and international standard runners were identified as iron deficient nonanemic (IDNA) and assigned to either an intravenous iron treatment group or placebo group. Participants completed three exercise tests to volitional exhaustion, as follows: before treatment, within 24 h, and 4 wk after treatment.


RESULTS
Serum ferritin, serum iron, and transferrin saturation were significantly improved in the iron group after intervention and compared with those in placebo (P < 0.05). Hepcidin levels were significantly greater before and after exercise after the iron injection (P < 0.05), and this was independent of changes in interleukin-6. There were no differences between groups in red cell indices, total hemoglobin mass, V˙O2max, submaximal blood lactate, running economy, RPE, or time to exhaustion (P > 0.05).


CONCLUSIONS
A single 500-mg intravenous iron injection is effective for improving iron status for at least 4 wk, but this does not lead to improved aerobic capacity. This investigation suggests that iron availability supersedes inflammation in the regulation of hepcidin in IDNA endurance athletes after acute intravascular iron injection treatment.
1Centre for Health, Applied Sport, and Exercise Science, St. Mary's University, Twickenham, UNITED KINGDOM; 2British Athletics, Hospital of St. John and St. Elizabeth, London, UNITED KINGDOM; 3Research Institute for Sport and Exercise Science, Liverpool John Moores University, Liverpool, UNITED KINGDOM; 4Division of Surgery, University College London, London, UNITED KINGDOM; 5ORRECO, Institute of Technology, Sligo, IRELAND; 6Department of Clinical Chemistry, Imperial College Healthcare National Health Service Trust, London, UNITED KINGDOM; and 7Research Department of Structural and Molecular Biology, University College, London, UNITED KINGDOM.
Richard J
RJ
Burden
Noel
N
Pollock
Gregory P
GP
Whyte
Toby
T
Richards
Brian
B
Moore
Mark
M
Busbridge
Surjit K
SK
Srai
James
J
Otto
Charles R
CR
Pedlar
D056352:Athletes; D004311:Double-Blind Method; D004909:Erythrocyte Indices / Q000502:physiology; D005080:Exercise Test; D005260:Female; D005293:Ferritins / Q000097:blood; D064451:Hepcidins / Q000097:blood; D006801:Humans; D007275:Injections, Intravenous; D015850:Interleukin-6 / Q000097:blood; D007501:Iron / Q000008:administration & dosage* / Q000378:metabolism*; D000090463:Iron Deficiencies; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology; D005082:Physical Exertion / Q000502:physiology*; D012420:Running / Q000502:physiology; D014168:Transferrin / Q000032:analysis; D055815:Young Adult
D064451:Hepcidins; D015850:Interleukin-6; D014168:Transferrin; D005293:Ferritins; D007501:Iron