Table 1.

Haematology, calculated fluid shifts, plasma acid-base variables and electrolyte concentrations during prolonged, submaximal exercise prior to, during and following saline (CON) and N-acetylcysteine (NAC) infusion

				Exercise time (min)
Variable	Treatment	Pre-infusion	Pre-exercise	15	30	45	Fatigue	Recovery 30 min
[Hb] (g dl−1)	CON	15.4 ± 0.3 *	15.7 ± 0.3	16.4 ± 0.3 *	16.4 ± 0.2 *	16.3 ± 0.2 *	16.7 ± 0.2 *	15.2 ± 0.2
	NAC	15.5 ± 0.3 *	15.7 ± 0.3	16.5 ± 0.3 *	16.4 ± 0.2 *	16.3 ± 0.2 *	16.9 ± 0.2 *	15.3 ± 0.2
Hct (%)	CON	44.1 ± 1.1	44.4 ± 1.1	46.6 ± 1.0 *	46.8 ± 1.0 *	46.7 ± 0.9 *	47.6 ± 1.0 *	43.1 ± 1.0
	NAC	43.9 ± 1.0	44.3 ± 0.8	47.0 ± 0.9 *	47.4 ± 0.8 *	47.0 ± 0.7 *	48.8 ± 1.0 *	43.8 ± 0.8
ΔPV (%)	CON	—	−2.2 ± 0.8 *	−9.7 ± 0.7 *	−10.1 ± 1.3 *	−9.5 ± 1.1 *	−11.8 ± 2.4 *	2.5 ± 2.2 *
	NAC	—	−2.0 ± 0.9 *	−11.2 ± 1.1 *	−11.4 ± 1.2 *	−10.0 ± 1.2 *	−14.9 ± 1.6 *	0.8 ± 2.1 *
[H+] (nmol l−1)	CON	39.1 ± 0.6	39.0 ± 0.6	43.5 ± 0.9 *	42.6 ± 1.0 *	42.0 ± 1.0 *	51.0 ± 2.4 *	41.0 ± 1.1 *
	NAC	39.2 ± 0.6	38.7 ± 0.7	43.7 ± 0.8 *	42.3 ± 0.9 *	41.9 ± 1.2 *	53.1 ± 1.6 *	41.1 ± 1.3 *
[HCO3−] (mmol l−1)	CON	27.3 ± 0.8	26.3 ± 0.9	20.8 ± 1.0 *	20.0 ± 1.0 *	20.6 ± 0.8 *	14.0 ± 0.7 *	22.7 ± 0.7 *
	NAC	28.0 ± 0.9	26.2 ± 0.8	19.3 ± 0.5 *	19.2 ± 0.6 *	19.6 ± 0.6 *	12.8 ± 0.6 *	21.0 ± 0.8 *
PCO2 (Torr)	CON	43.4 ± 1.3	42.2 ± 1.2	36.5 ± 1.3	36.0 ± 1.2*	36.1 ± 0.9 *	30.7 ± 1.6 *	38.3 ± 1.0 *
	NAC	45.5 ± 0.7	42.4 ± 1.5	37.3 ± 1.4	34.4 ± 0.4 *	34.9 ± 1.1 *	28.7 ± 0.7 *	36.7 ± 1.0*
[Na+] (mmol l−1)	CON	140.3 ± 0.8	139.4 ± 0.8	142.0 ± 0.7 *	142.2 ± 0.6 *	141.2 ± 0.6 *	145.0 ± 0.6 *	137.9 ± 0.5
	NAC	139.3 ± 0.7	139.7 ± 0.7	141.3 ± 0.6 *	141.2 ± 0.7 *	141.8 ± 0.7 *	146.2 ± 1.0 *	139.0 ± 0.6
[Cl−] (mmol l−1)	CON	104.8 ± 1.0	103.5 ± 0.9	105.3 ± 1.0	102.3 ± 1.1	104.1 ± 0.9	104.8 ± 1.6	104.9 ± 1.5
	NAC	105.3 ± 0.6	105.6 ± 1.0	105.1 ± 0.7	104.1 ± 0.4	103.5 ± 0.8	104.4 ± 0.9	103.3 ± 0.6
[Ca2+] (mmol l−1)	CON	1.24 ± 0.02	1.27 ± 0.02	1.24 ± 0.02	1.28 ± 0.02	1.27 ± 0.02	1.28 ± 0.01 *	1.23 ± 0.02
	NAC	1.24 ± 0.02	1.25 ± 0.02	1.25 ± 0.01	1.24 ± 0.02	1.25 ± 0.01	1.30 ± 0.02 *	1.21 ± 0.01

Different from preinfusion, main effect for time, P < 0.05. Mean ± s.e.m., n = 8.