Effects of iron status on performance during maximal and submaximal cycle ergometry in trained male cyclists

Hinton, P.; Wendtland, C.; Sinclair, L.

FASEB Journal 17(4-5): Abstract No. 199


The objective of this study was to investigate the relationships between iron status and physical performance during submaximal and maximal exercise in trained males. We hypothesized that iron status indicators involved in oxygen transport (hemoglobin, Hb; hematocrit, Hct) would be related to physical performance during maximal exercise and that indicators of iron stores (serum ferritin, sFer) and tissue iron need (serum transferrin receptor, sTfR) would be related to physical performance during submaximal exercise. Nineteen trained (VO2max=55.1(1.5 mL/kg/min) men aged 19-37 years completed a VO2max test and a 60 minute submaximal (60% of VO2max) test on a cycle ergometer. Heart rate (HR), O2 consumption, CO2 production, minute ventilation and workload were monitored continuously for the determination of ventilatory threshold (VT), respiratory exchange ratio (RER), energy expenditure and gross efficiency. Hb, Hct, sFer, serum iron, transferrin saturation and sTfR were determined in blood drawn immediately prior to the VO2max test. Multiple linear regression was used to examine relationships between iron status and performance variables. Three subjects met the criteria for anemia (Hb<14 g/dL).