High leg perfusion values have been observed during knee-extension or cycling exercise (> 250 ml blood 100 g^-1 min^-1) (Andersen & Saltin, 1985; Blomstrand et al. 1997). The aim of this study was to investigate whether a similar perfusion can be achieved during maximal arm cranking exercise.

Following ethics committee approval and informed written consent, eight healthy subjects (mean ± S.D. age 21 ± 1 years, height 1.82 ± 0.06 m, body mass 76.2 ± 8.2 kg), performed incremental arm cranking exercise to exhaustion. The exercise protocol consisted of several 6 min exercise stages separated by equal resting time. All subjects started cranking without any load at ~70 revolutions per minute followed by increments of 35 W for each subsequent stage. At each exercise stage arm blood flow (ãÃQ_ARM) was measured with a thermodilution catheter placed in v. axillaris and using the saline bolus injection technique. Arterial and axillary venous blood samples were taken at the end of each stage for blood gas analyses and calculation of arm O₂ consumption (Ω_O2,ARM) according to the Fick principle. Pulmonary oxygen uptake (Ω_O2,TOT) was measured online from expired gas analysis. Arterial blood pressure was measured at the radial artery. Perfused muscle mass was estimated by dual-energy X-ray absorptiometry. The correlation coefficient (r) was used to evaluate the association between variables and all data are presented as means (± S.E.M.).

During maximal arm cranking mean ± S.E.M. peak ãÃQ_ARM was 4.55 ± 0.26 l min^-1. The Ω_O2,ARM was 0.60 ± 0.04 l O₂ min^-1 with a Ω_O2,TOT of 2.87 ± 0.22 l O₂ min^-1. Both ãÃQ_ARM and Ω_O2,ARM were linearly related with workload (r = 0.99) and Ω_O2,TOT (r = 0.97). Mean arterial pressure and arm vascular resistance at the final stage was 113 ± 3 mmHg and 24.8 ± 1.3 mmHg (min l)^-1, respectively. The estimated perfused muscle mass was 3.3 ± 0.1 kg and the calculated perfusion was 141 ± 11 ml blood 100 g^-1 min^-1.

Perfusion of the arms was significantly lower than the values which have been reported for the legs during leg exercise. This discrepancy suggests that the perfusion values reported for the lower limbs cannot be generalised to all skeletal muscles.

S.V. was supported by a Marie Curie Fellowship from the European Union.