Effects of one-legged endurance training on femoral arterial and venous size in healthy humans

Abstract

The cross-sectional area (CSA) of large-conductance arteries increases in response to endurance training in humans. To determine whether training-induced changes in arterial structure are systemic in nature or, rather, are confined to the arteries supplying exercising muscles, we studied 10 young men who performed one-legged cycle training [80% of one-legged peak O2 uptake (VO2 peak)), 40 min/day, 4 days/wk] for 6 wk and detraining for another 6 wk. There were no significant differences in baseline one-legged VO2 peak) and CSA of the common femoral artery and vein (via B-mode ultrasound) between experimental and control legs. In the experimental leg, one-legged VO2 peak) increased 16% [from 3.0 +/- 0.1 to 3.4 +/- 0.1 (SE) l/min], arterial CSA increased 16% (from 84 +/- 3 to 97 +/- 5 mm2), and venous CSA increased 46% (from 56 +/- 5 to 82 +/- 5 mm2) after endurance training. These changes returned to baseline during detraining. There were no changes in one-legged VO2 peak) and arterial CSA in the control leg, whereas femoral venous CSA in the control leg significantly increased 24% (from 54 +/- 5 to 67 +/- 4 mm2) during training. Changes in femoral arterial and venous CSA in the experimental leg were positively and significantly related to corresponding changes in one-legged VO2 peak) (r = 0.86 and 0.76, respectively), whereas there were no such relations in the control leg (r = 0.10 and 0.17). When stepwise regression analysis was performed, a primary determinant of change in VO2 peak) was change in femoral arterial CSA, explaining approximately 70% of the variability. These results support the hypothesis that the regional increase in blood flow, rather than systemic factors, is associated with the training-induced arterial expansion. Femoral arterial expansion may contribute, at least in part, to improvement in efficiency of blood transport from the heart to exercising muscles and may facilitate achievement of aerobic work capacity.

Rapid and Extensive Arterial Adaptations After Spinal Cord Injury

“…Persistent changes in blood flow cause alterations in blood vessel architecture to normalize wall shear stress. 3,5 Previous training studies 29,30 in humans have suggested that conduit arteries adapt their base- line diameters to peak shear stress and peak oxygen consumption rather than to resting blood flow. Parallel to this reasoning, the decrease in diameter in SCI may represent an inward remodeling as an adaptation to a total lack of periods of high shear stress in the paralyzed legs of people with SCI.…”

Relationship between Large and Small Arterial Compliance and Regional Body Composition in Middle-Aged and Elderly Adults

“…The findings of this study suggest that decreased compliance of peripheral small arteries may partly reduce peripheral blood flow, resulting in reduction in muscle volume in middle-aged and elderly individuals. On the other hand, recent studies have shown that moderate or high-intensity physical training induced an increase in the diameter of the femoral artery [29][30][31] , whereas femoral arterial compliance did not change in contrast with carotid arterial compliance 32) . Also, a previous study indicated that resistance training increased blood flow and vascular conductance of the femoral artery in middle-aged and elderly adults 33) .…”

The effect of bed rest and an exercise countermeasure on leg venous function

“…This difference in diameter response suggests that the venous and arterial vascular systems are susceptible to different stimuli, when exposed to deconditioning. As arterial adaptations were ascribed to mainly regional factors due to (the lack of) physical exercise, such as changes in blood flow and (peak) shear stress to the vessel wall (Bleeker et al 2005b;Miyachi et al 2001), veins might be primarily responsive to changes in pressure or blood volume (Arbeille et al 2001). …”