Table 1.

Arm metabolic responses to arm (A) and combined arm plus leg exercise (A+L)

	Rest	A	A + L
O2 content, arterial (ml 1−1)	200 ± 4	211 ± 5	214 ± 5
Venous (ml 1 −1)	128 ± 9	98 ± 5*	73 ± 6*†
(a-v) diff. (ml 1−1)	59 ± 4	122 ± 15*	150 ± 21*†
pH, arterial	7.42 ± 0.01	7.35 ± 0.02*	7.31 ± 0.02*†
Venous	7.35 ± 0.02	7.21 ± 0.02*	7.16 ± 0.02*†
PCO2, arterial (kPa)	4.69 ± 0.00	4.00 ± 0.00*	4.00 ± 0.10*
Venous (kPa)	6.19 ± 0.10	7.59 ± 0.00*	7.90 ± 0.05*
HCO3−, arterial (mm)	22 ± 0	17 ± 1*	15 ± 1*†
Venous (mm)	27 ± 0	24 ± 0*	22 ± 1*†
Lac, arterial (mm)	0.8 ± 0.1	7.0 ± 0.9*	11.3 ± 1.2*†
Venous (mm)	1.1 ± 0.1	10.1 ± 1.2*	12.8 ± 1.4*†
(a-v) diff. (mm)	−0.1 ± 0.1	−3.2 ± 0.5*	−1.7 ± 0.3*†
Release (mmol min−1)	0.0 ± 0.0	7.4 ± 0.6*	3.7 ± 0.6*†
Glu, arterial (mm)	4.9 ± 0.3	4.7 ± 0.2	5.1 ± 0.2
Venous (mm)	5.2 ± 0.1	5.2 ± 0.2	5.4 ± 0.2
(a-v) diff. (mm)	−0.3 ± 0.2	−0.5 ± 0.2	−0.2 ± 0.2†
Release (mmol min−1)	0.1 ± 0.1	1.6 ± 0.8	0.7 ± 0.4
K+, arterial (mm)	3.7 ± 0.2	4.5 ± 0.3*	5.4 ± 0.3*†
Venous (mm)	4.5 ± 0.1	6.1 ± 0.2*	7.0 ± 0.4*†
(a-v) diff. (mm)	−0.8 ± 0.1	−1.6 ± 0.3*	−1.6 ± 0.3*
Release (mmol min−1)	0.3 ± 0.0	4.5 ± 1.1*	3.4 ± 0.7*
Na+, arterial (mm)	140 ± 0	144 ± 1*	145 ± 1*
Venous (mm)	140 ± 1	145 ± 0*	146 ± 0*
(a-v) diff (mm)	1 ± 0	−1 ± 0	0 ± 0
Release (mmol min−1)	0 ± 0	3 ± 1	1 ± 1
Ca2+, arterial (mm)	1.14 ± 0.02	1.19 ± 0.03	1.25 ± 0.03*†
Venous (mm)	1.29 ± 0.01	1.39 ± 0.02*	1.39 ± 0.02*
(a-v) diff (mm)	−0.14 ± 0.02	−0.19 ± 0.04	−0.14 ± 0.03
Release (mmol min−1)	0.02 ± 0.01	0.53 ± 0.16*	0.31 ± 0.09*

Values are means ± s.e.m.; (n = 10). (a-v) diff., arterial axillary venous oxygen difference; pH, H⁺ concentration; P^CO2, carbon dioxide partial pressure; HCO₃⁻, bicarbonate; Lac, lactate; Glu, glucose; K⁺, potassium; Na⁺, sodium; Ca²⁺, calcium.

^*Different from rest, P < 0.05

^†different from A, P < 0.05.