The Effects Of Iron Depletion Without Anemia On Training And Performance In Female Collegiate Rowers
This dissertation investigated the effects of iron depletion without anemia (IDNA) on physical performance and training in female collegiate rowers. In a cross sectional study, 165 rowers were screened for iron status at the beginning of a competitive season (10% anemic, 30% IDNA, Hgb>12.0, Hgb>12.0 g/dL and ferritin <20 [MICRO SIGN]g/L). IDNA rowers reported 2K times that were 21 seconds slower compared to rowers with normal iron status (p=0.004). During the first week of training, 48 rowers (n=24 IDNA) had their physical performance assessed (VO2peak, 4K time, gross energetic efficiency) and recorded their training regimen. Compared to rowers with normal iron status, IDNA rowers trained ~10 minutes/d less (p=0.02), and had a 0.3 L/min lower VO2peak (p=0.03). Less highly-trained rowers with poor iron status had a lower VO2peak (-0.32 L/min, p=0.02), and were less energetically-efficient (-1.7%, p=0.09) compared to more highly-trained rowers with poor iron status. In a randomized controlled trial, 43 rowers received 100 mg/d FeSO4 (n=22) or placebo (n=21) for 6 weeks, and completed daily training logs. Iron status, performance, and training quality were assessed at baseline and 6 weeks. Thirty-one rowers (n=15 iron, 16 placebo) completed the trial. Rowers supplemented with iron improved their body iron stores (log ferritin, total body iron, p=0.07), and those with most depleted stores at baseline improved the most. Blood lactate concentration during the first 2000m of a 4K TT and 5 min post-recovery was significantly lower in the iron group (p<0.01), and rowers in the iron group had a greater improvement in work efficiency (p=0.15) compared to placebo. Additionally, the energetic efficiency of those rowers with poorer baseline stores (ferritin <20 [MICRO SIGN]g/L) benefitted more from supplementation. Finally, rowers in the iron group had an improved training quality score (p=0.03) compared to those in the placebo group. We conclude that iron status should be screened at the beginning of a training season, and that iron supplementation (~15 mg iron/d) improves iron stores in female rowers during training, especially in the most deplete. The iron status of those with marginal/low stores should be monitored to prevent detrimental effects on training and performance.
Iron depletion; female athletes; rowers; Iron supplementation; lactate; VO2peak; Physical performance; endurance training
Haas, Jere Douglas
Olson, Christine Marie; Sobal, Jeffery; O'Brien, Kimberly O
Ph. D., Nutrition
Doctor of Philosophy
dissertation or thesis