Non Invasive Measurement of Brachioradial Muscle V0₂-Blood Flow Relationship During Graded Isometric Exercise

Abstract

It is generally agreeded that the rate of blood flow in exercising skeletal muscle has a relevant influence on the biochemical processes proceeding in that tissue and on the cause of fatigue. The investigation of the relationship between blood flow and oxygen consumption (V0₂) of the limbs is thus of great relevance in exercise physiology of healthy subjects. In patients with cardiovascular disease the reduction of blood supply can limit the efficiency of skeletal muscle influencing functions like movements and respiration (Weber, 1982). As regards blood supply during exercise, although some experimental evidences suggest that in strongly stimulated muscle the vessels are dilated after 15 sec of contraction beginning, the mechanical compression occurring on the vascular bed has been widely reported to induce a blood flow limitation (Bonde-Petersen, 1975, Moller 1979). Different methods have been developed for the assessment of muscle blood flow and V0₂, but whereas the measurement of flow can be performed non invasively, the oxygen uptake of the limbs is usually calculated by multiplying blood flow with arterio-venous oxygen content difference (Mottram, 1955, Hartling, 1989).