Four consecutive 6 min low-intensity single-legged knee-extension exercise bouts (LI, EX1–4) were performed interspersed with 30 min rest periods, followed by four 6 min high-intensity single-legged knee-extension exercise bouts (HI, EX5–8) interspersed with 45 min rest periods. During EX1–2 and EX5–6, femoral arterial blood samples (BSa) and venous blood samples (BSv) were collected and thigh blood flow was measured. During EX3 and EX7, the vein-to-artery transit time (TTv–a) was determined and venous blood samples were collected. During EX4 and EX8, the artery-to-vein transit time (TTa–v) was determined.