Peak aerobic exercise capacity and the ability to sustain a given absolute submaximal workload decline with advancing age. Ageing is also associated with a lower level of blood flow and oxygen delivery to the exercising muscles; however, to what extent this attenuated exercise hyperaemia in aged has functional consequences remains undisclosed. Furthermore, given that physical inactivity can mimic many of the physiological changes associated with aging a fundamental understanding of the influences of primary ageing versus physical inactivity is still lacking. Separating the effects of ageing and physical activity is challenging due to the complex interplay between these physiological stimuli; still, observations from cross-sectional and longitudinal studies have provided some insight. Physical activity appears to have the potential to offset the decline in blood flow to contracting skeletal muscle normally observed in aged individuals during submaximal loads, thus ensuring adequate oxygen delivery to meet the metabolic demand. This essential aspect of oxidative metabolism is likely to be of paramount importance for functional capacity. The mechanisms underlying the effects of physical activity are likely to include improved vascular function and ability for functional sympatholysis. The latter is defined as the attenuation of the vasoconstrictor effect of sympathetic nervous activity in contracting skeletal muscle which is thought to be important for adequate perfusion of the contracting fibers. Collectively, the magnitude of blood flow and oxygen uptake in active skeletal muscle of aged individuals seems to a large extent to be related to the level of physical activity.