Four Weeks of IV Iron Supplementation Reduces Perceived Fatigue and Mood Disturbance in Distance Runners

Abstract

PurposeTo determine the effect of intravenous iron supplementation on performance, fatigue and overall mood in runners without clinical iron deficiency.MethodsFourteen distance runners with serum ferritin 30–100 µg·L−1 were randomly assigned to receive three blinded injections of intravenous ferric-carboxymaltose (2 ml, 100 mg, IRON) or normal saline (PLACEBO) over four weeks (weeks 0, 2, 4). Athletes performed a 3,000 m time trial and 10×400 m monitored training session on consecutive days at week 0 and again following each injection. Hemoglobin mass (Hbmass) was assessed via carbon monoxide rebreathing at weeks 0 and 6. Fatigue and mood were determined bi-weekly until week 6 via Total Fatigue Score (TFS) and Total Mood Disturbance (TMD) using the Brief Fatigue Inventory and Brunel Mood Scale. Data were analyzed using magnitude-based inferences, based on the unequal variances t-statistic and Cohen's Effect sizes (ES).ResultsSerum ferritin increased in IRON only (Week 0: 62.8±21.9, Week 4: 128.1±46.6 µg·L−1; p = 0.002) and remained elevated two weeks after the final injection (127.0±66.3 µg·L−1, p = 0.01), without significant changes in Hbmass. Supplementation had a moderate effect on TMD of IRON (ES -0.77) with scores at week 6 lower than PLACEBO (ES -1.58, p = 0.02). Similarly, at week 6, TFS was significantly improved in IRON vs. PLACEBO (ES –1.54, p = 0.05). There were no significant improvements in 3,000 m time in either group (Week 0 vs. Week 4; Iron: 625.6±55.5 s vs. 625.4±52.7 s; PLACEBO: 624.8±47.2 s vs. 639.1±59.7 s); but IRON reduced their average time for the 10×400 m training session at week 2 (Week 0: 78.0±6.6 s, Week 2: 77.2±6.3; ES–0.20, p = 0.004).ConclusionDuring 6 weeks of training, intravenous iron supplementation improved perceived fatigue and mood of trained athletes with no clinical iron deficiency, without concurrent improvements in oxygen transport capacity or performance.

Erythroferrone as a sensitive biomarker to detect stimulation of erythropoiesis

“…16 Some endurance athletes inject iron to maintain a high serum ferritin concentration. 18 Iron injection is not considered to be a doping method, but could potentially interfere with antidoping biomarkers involved in iron metabolism. 18 Iron injection is not considered to be a doping method, but could potentially interfere with antidoping biomarkers involved in iron metabolism.…”

“…17 Intravenous iron supplementation improves fatigue and overall mood in runners without a clinical iron deficiency. 18 Iron injection is not considered to be a doping method, but could potentially interfere with antidoping biomarkers involved in iron metabolism. In the present study, we identified that iron injection did not affect the ERFE concentration ( Figure 3B).…”

Sports Foods and Dietary Supplements for Optimal Function and Performance Enhancement in Track-and-Field Athletes

“…For instance, it is well known that iron deficiency can impair hematologic adaptation, which left untreated can negatively impact on athletic performance (Garvican et al, 2011). However, nutritional correction of this issue via various intervention strategies has been regularly shown to have a positive impact on correcting the underlying deficiency and enhancing athlete performance (Dawson et al, 2006;Garvican et al, 2011;Woods et al, 2014).…”

Common causes of dyspnoea in athletes: a practical approach for diagnosis and management

“…Total Hb mass, as measured using a carbon monoxide rebreathing technique, reflects the red cell mass and Hb concentration, and is emerging as potential novel method for evaluating the oxygen carrying capacity of the blood in athletes with iron deficiency. However, some studies have questioned the sensitivity of using tHb mass to evaluate responsiveness to iron-related interventions [ 63 , 64 ], whereas others have found it clinically useful [ 64 ], suggesting further research is necessary.…”

“…Clinicians should use laboratory testing to confirm that iron supplementation is actually necessary, as increased iron stores have been associated with gastrointestinal distress, liver malignoma and impaired immune effector functions [ 56 ]. Intramuscular and intravascular iron injections have not provided definitive positive outcomes on athletic performance, but in some cases have improved perceived fatigue levels in nondeficient athletes [ 64 ]. P eeling et al.…”