A Case Study of an Iron Deficient Female Olympic 1500m Runner

This case study examines the impact of low serum ferritin (sFe) on physiological assessment measures and performance in a young female 1500m runner undertaking approximately 95-130 km·week-1 training. The study spans 4 race seasons and an Olympic Games. Within this period, 25 venous blood samples were analysed for sFe and haemoglobin (Hb); Running economy, VO2max and lactate threshold were measured on 6 occasions, each separated by 8-10 months. Training was carefully monitored including 65 monitored treadmill training runs (targetting an intensity associated with the onset of blood lactate accumulation) using blood lactate and heart rate. Performances at competitive track events were recorded. All data were compared longitudinally. Mean sFe was 24.5­+7.6μg·L-1 (range:10-47) appearing to be in gradual decline with the exception of two data points (37 and 47μg·L-1) following parenteral iron injections prior to championships, where the lowest values tended to occur, coinciding with peak training volumes. 1500m performance improved each season from 4:12.8 in year 1 to 4:03.5 in year 4. VO2max (69.8+2.0ml·kg-1·min-1) and running economy (% of VO2max at a fixed speed of 16km·h-1; max: 87.8%, min: 80.3%) were stable across time and lactate threshold improved (from 14 to 15.5km·hr-1). Evidence of anaemia (Hb<12g·dL-1) was absent. These unique data demonstrate that in one endurance athlete performance can continue to improve despite an apparent iron deficiency. Raising training volume may have caused increased iron utilisation, however, the effect of this on performance is unknown. Iron injections were effective in raising sFe in the short term but did not appear to affect the long term pattern.