Aging attenuates leg blood flow during exercise (1,340 vs 1,523 ml/kg/min at 40% WRmax in old vs young subjects) but does not impact forearm blood flow.
Observational (n=14)
Does aging have differing effects on blood flow in the arm and leg during exercise?
Aging induces limb-specific alterations in exercise blood flow regulation, resulting in reductions in leg blood flow during exercise but not impacting forearm blood flow.
Absolute Event Rate: 1340% vs 1523%
Aging appears to attenuate leg blood flow during exercise; in contrast, such data are scant and do not support this contention in the arm. Therefore, to determine whether aging has differing effects on blood flow in the arm and leg, eight young (22 +/- 6 yr) and six old (71 +/- 15 yr) subjects separately performed dynamic knee extensor 0, 3, 6, 9 W; 20, 40, 60% maximal work rate (WRmax) and handgrip exercise (3, 6, 9 kg at 0.5 Hz; 20, 40, 60% WRmax). Arterial diameter, blood velocity (Doppler ultrasound), and arterial blood pressure (radial tonometry) were measured simultaneously at each of the submaximal workloads. Quadriceps muscle mass was smaller in the old (1.6 +/- 0.1 kg) than the young (2.1 +/- 0.2 kg). When normalized for this difference in muscle mass, resting seated blood flow was similar in young and old subjects (young, 115 +/- 28; old, 114 +/- 39 ml x g(-1) x min(-1)). During exercise, blood flow and vascular conductance were attenuated in the old whether expressed in absolute terms for a given absolute workload or more appropriately expressed as blood flow per unit muscle mass at a given relative exercise intensity (young, 1,523 +/- 329; old, 1,340 +/- 157 ml x kg(-1) x min(-1) at 40% WRmax). In contrast, aging did not affect forearm muscle mass or attenuate rest or exercise blood flow or vascular conductance in the arm. In conclusion, aging induces limb-specific alterations in exercise blood flow regulation. These alterations result in reductions in leg blood flow during exercise but do not impact forearm blood flow.
Donato et al. (Sat,) reported a observational. Aging vs. Young age was evaluated on Leg blood flow per unit muscle mass at 40% maximal work rate. Aging attenuates leg blood flow during exercise (1,340 vs 1,523 ml/kg/min at 40% WRmax in old vs young subjects) but does not impact forearm blood flow.