Four weeks of IV iron supplementation reduces perceived fatigue and mood disturbance in distance runners.
Study Goal
To determine the effect of intravenous iron supplementation on performance, fatigue, and mood in runners without clinical iron deficiency.
Results Summary
Intravenous iron supplementation improved perceived fatigue and mood but did not enhance oxygen transport capacity or overall performance in 3,000 m time trials. However, it reduced average time in 10 × 400 m training sessions at week 2.
Population
Fourteen distance runners with serum ferritin levels of 30-100 µg · L(-1).
Effective Dosage
Three injections of 2 ml (100 mg) intravenous ferric-carboxymaltose over four weeks (weeks 0, 2, 4).
Duration
6 weeks
Interactions
None mentioned
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
intravenous ferric-carboxymaltose | increase | serum ferritin | distance runners with serum ferritin 30-100 µg · L(-1) | Week 0: 62.8 ± 21.9, Week 4: 128.1 ± 46.6 µg · L(-1) | increased | #1 |
intravenous ferric-carboxymaltose | increase | serum ferritin | distance runners with serum ferritin 30-100 µg · L(-1) | 127.0 ± 66.3 µg · L(-1) | remained elevated | #2 |
intravenous ferric-carboxymaltose | no change | hemoglobin mass (Hbmass) | distance runners with serum ferritin 30-100 µg · L(-1) | - | without significant changes | #3 |
intravenous ferric-carboxymaltose | decrease | Total Mood Disturbance (TMD) | distance runners with serum ferritin 30-100 µg · L(-1) | ES -0.77 | had a moderate effect | #4 |
intravenous ferric-carboxymaltose | decrease | Total Mood Disturbance (TMD) | distance runners with serum ferritin 30-100 µg · L(-1) | ES -1.58 | scores at week 6 lower than PLACEBO | #5 |
intravenous ferric-carboxymaltose | decrease | Total Fatigue Score (TFS) | distance runners with serum ferritin 30-100 µg · L(-1) | ES -1.54 | significantly improved | #6 |
intravenous ferric-carboxymaltose | no change | 3,000 m time | distance runners with serum ferritin 30-100 µg · L(-1) | Week 0: 625.6 ± 55.5 s vs. Week 4: 625.4 ± 52.7 s | no significant improvements | #7 |
intravenous ferric-carboxymaltose | decrease | 10 × 400 m training session | distance runners with serum ferritin 30-100 µg · L(-1) | Week 0: 78.0 ± 6.6 s, Week 2: 77.2 ± 6.3; ES-0.20 | reduced their average time | #8 |
intravenous iron supplementation | improve | perceived fatigue and mood | trained athletes with no clinical iron deficiency | - | improved perceived fatigue and mood | #9 |
intravenous iron supplementation | no change | oxygen transport capacity or performance | trained athletes with no clinical iron deficiency | - | without concurrent improvements | #10 |
PURPOSE: To determine the effect of intravenous iron supplementation on performance, fatigue and overall mood in runners without clinical iron deficiency. METHODS: Fourteen 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). RESULTS: Serum 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). CONCLUSION: During 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.