Differences in vascular function between trained and untrained limbs assessed by near-infrared spectroscopy

Purpose The aim of this study was to examine whether differences in vascular responsiveness associated with training status would be more prominent in the trained limb (leg) than in the untrained limb (arm) microvasculature. Methods Thirteen untrained (26 ± 5 year) and twelve trained (29 ± 4 year) healthy men were submitted to a vascular occlusion test (VOT) (2 min baseline, 5 min occlusion, and 8 min re-oxygenation). The oxygen saturation signal (StO 2 ) was assessed using near-infrared spectroscopy (NIRS) throughout the VOT. Vascular responsiveness within the microvasculature was evaluated by the re-oxygenation Slope 2 (Slope 2 StO 2 ) and the area under the curve (StO 2AUC ) of (StO 2 ) signal during re-oxygenation in the leg and arm. Results There was a significant interaction between training status and limb for the slope 2 StO 2 ( P