Table 4.

Variables measured at the point of volitional fatigue during incremental CPET.

Iron status	Iron deficient (n = 13)				Iron replete (n = 13)				P-value (RM-ANOVA)
Intervention	Iron (n = 7)		Saline (n = 6)		Iron (n = 7)		Saline (n = 6)
Visit	1	2	1	2	1	2	1	2
Power, W	180 ± 49	181 ± 46	182 ± 52	178 ± 54	216 ± 42	212 ± 43	184 ± 45	186 ± 49	Iron status = 0.31 Visit & intervention = 0.62 Iron status, visit & intervention = 0.027
$\dot{\mathrm{V}}$o2, ml/kg	38.0 ± 11.3	38.0 ± 10.9	39.0 ± 8.2	36.1 ± 8.3	41.3 ± 7.7	41.4 ± 9.8	39.6 ± 4.7	39.3 ± 5.6	Iron status = 0.45 Visit & intervention = 0.10 Iron status, visit & intervention = 0.22
RER	1.15 ± 0.08	1.16 ± 0.09	1.14 ± 0.07	1.14 ± 0.06	1.15 ± 0.05	1.12 ± 0.02	1.12 ± 0.04	1.12 ± 0.06	Iron status = 0.40 Visit & intervention = 0.84 Iron status, visit & intervention = 0.33
$\dot{\mathrm{V}}$E, L/min	102 ± 42	98 ± 40	98 ± 21	100 ± 16	123 ± 33	121 ± 32	93 ± 26	96 ± 28	Iron status = 0.50 Visit & intervention = 0.11 Iron status, visit & intervention = 0.86
Oxygen pulse, ml/beat	12.4 ± 3.1	12.8 ± 3.1	13.0 ± 3.7	12.6 ± 3.5	14.9 ± 3.8	15.4 ± 3.9	13.1 ± 2.9	12.6 ± 2.8	Iron status = 0.34 Visit & intervention = 0.036 Iron status, visit & intervention = 0.89
RPE	18.6 ± 1.5	18.3 ± 1.1	18.0 ± 1.8	17.8 ± 2.6	19.0 ± 1.0	18.9 ± 1.1	18.3 ± 1.0	18.5 ± 1.0	Iron status = 0.37 Visit & intervention = 0.61 Iron status, visit & intervention = 0.82

P-values are given for: (i) the effect of baseline iron status; (ii) the interaction between visit and intervention (the effect of IV iron); and (iii) the interaction between baseline iron status, visit, and intervention (whether any effect of IV iron differed according to baseline iron status). Values are means ± SD. Statistically significant P-values appear in bold. RER, respiratory exchange ratio; $\dot{\mathrm{V}}$E, minute ventilation; oxygen pulse is defined as $\dot{\mathrm{V}}$o₂ divided by heart rate; RPE, rating of perceived exertion.