What acute cardiovascular responses accompany the transition from sitting to walking?

Stroke volume increases (not decreases) during the onset of exercise due to greater venous return and sympathetic stimulation.

Systolic blood pressure rises with exercise onset because cardiac output increases, so it does not decrease.

The transition from rest to light exercise requires increased oxygen delivery and utilization. Cardiac output rises because both heart rate and stroke volume increase, and the arteriovenous oxygen difference (a-vO2 diff) widens as working muscles extract more oxygen from the blood. These two responses together reflect the acute coupling of central delivery and peripheral extraction.

Diastolic blood pressure typically remains stable or decreases during dynamic aerobic exercise like walking due to peripheral vasodilation, not increases.