Table 2.

Blood variables at rest and during incremental cycling to exhaustion

		Incremental cycling (% peak power)
	Rest	25%	50%	75%	90%	100%
Haemoglobin (g·l−1)
a	153 ± 2	155 ± 2	158 ± 3*	159 ± 3*	161 ± 3*	166 ± 3*
cv	157 ± 4	160 ± 4	161 ± 3	161 ± 4	163 ± 4	168 ± 5*
fv	158 ± 3	154 ± 4	155 ± 5	157 ± 5	161 ± 4	167 ± 4*
(mmHg)
a	112 ± 2	102 ± 1*	95 ± 2*	92 ± 3*	94 ± 3*	99 ± 3*
cv	40 ± 1	32 ± 2*	25 ± 1*	22 ± 1*	22 ± 2*	22 ± 2*
fv	31 ± 1	23 ± 1*	20 ± 1*	18 ± 1*	18 ± 1*	17 ± 1*
O2 saturation (%)
a	98.8 ± 0.1	98.1 ± 0.1	97.3 ± 0.2*	96.5 ± 0.4*	95.9 ± 0.4*	95.3 ± 0.4*
cv	70.5 ± 0.6	45.5 ± 3.5*	35.0 ± 2.8*	26.5 ± 2.7*	21.5 ± 3.0*	17.3 ± 2.3*
fv	49.5 ± 2.8	34.8 ± 1.3*	26.3 ± 1.0*	20.2 ± 1.0*	16.8 ± 1.2*	12.6 ± 1.2*
O2 content (ml·l−1)
a	206 ± 3	207 ± 3	209 ± 3	209 ± 4	210 ± 4	214 ± 4*
cv	149 ± 4	99 ± 9*	77 ± 7*	59 ± 7*	49 ± 8*	40 ± 6*
fv	105 ± 5	69 ± 3*	52 ± 3*	39 ± 3*	33 ± 3*	26 ± 3*
(mmHg)
a	40 ± 1	41 ± 1	42 ± 0*	43 ± 1	42 ± 1*	36 ± 1*
cv	49 ± 1	56 ± 1	60 ± 1*	71 ± 1*	81 ± 4*	85 ± 3*
fv	56 ± 1	57 ± 1	64 ± 2	72 ± 1*	85 ± 2*	91 ± 3*
pH
a	7.38 ± 0.01	7.38 ± 0.01	7.36 ± 0.01	7.34 ± 0.01*	7.28 ± 0.02*	7.19 ± 0.02*
cv	7.34 ± 0.01	7.32 ± 0.01	7.31 ± 0.01	7.25 ± 0.01*	7.19 ± 0.02*	7.07 ± 0.02*
fv	7.31 ± 0.01	7.31 ± 0.01	7.28 ± 0.01	7.22 ± 0.01*	7.13 ± 0.03*	7.02 ± 0.03*
Lactate (mmol·l−1)
a	1.1 ± 0.1	1.1 ± 0.1	1.6 ± 0.1*	3.1 ± 0.2*	7.0 ± 0.5*	14.0 ± 0.7*
cv	1.0 ± 0.1	1.2 ± 0.1	1.7 ± 0.3*	3.8 ± 0.6*	7.9 ± 0.9*	14.1 ± 1.1*
fv	1.0 ± 0.1	1.1 ± 0.1	1.7 ± 0.1*	3.3 ± 0.2*	7.8 ± 0.8*	15.2 ± 0.7*
Glucose (mmol·l−1)
a	5.2 ± 0.2	4.9 ± 0.2	5.0 ± 0.2	5.0 ± 0.2	5.1 ± 0.2	5.1 ± 0.2
cv	4.9 ± 0.2	4.6 ± 0.2	4.7 ± 0.2	4.7 ± 0.3	4.7 ± 0.2	4.9 ± 0.2
fv	4.6 ± 0.2	4.5 ± 0.2	4.8 ± 0.2	4.8 ± 0.2	4.8 ± 0.3	5.0 ± 0.3*
Temperature (oC)
fv	37.5 ± 0.1	37.6 ± 0.1*	37.8 ± 0.1*	38.1 ± 0.1*	38.5 ± 0.1*	38.8 ± 0.1*

Values are means ± s.e.m. for 12 subjects, central venous (cv) values (n = 8). a. arterial. cv. right atrium or pulmonary artery. fv. femoral venous. . and pH values were corrected for changes in blood temperature.

^*Different from rest, P < 0.05.