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Heart rate increases before exercise due to sympathetic nervous system anticipation of exercise
Heart rate during exercise increases similar to VO2 (However, VO2 is more closely related to the actual workout intensity)
Four Factors of Stroke Volume:
1) Increased venous blood return (EDV)—trained individuals have enhanced blood return to the heart which increases EDV (therefore the heart can pump more blood)
2) Ventricular stretch (capacity to enlarge)—This increased stretch leads to a more poweful ventricular contraction (also referred to as Preload or Frank-Starling mechanism)
3) Ventricular contractility—the heart is a muscle, and like all muscles that are trained has the capacity to contract with greater force production (thus ejecting more blood)
4) Aortic and pulmonary artery blood pressure—healthy arteries have better vasodilation, allowing blood to travel much more efficiently through the systemic circuit
Systolic blood pressure increases with exercise intensity. Diastolic pressure should stay pretty stable in healthy individuals (sometimes it actually drops due to the vasodilation of arteries)
a-vO2 difference shows enhanced extraction of oxygen at capilaries in muscle cells
Blood flow to muscle is dramatically enhanced
Important Note:The Graph Below is NOT included in Exam 3. We discuss adapations later in the semester. Laser focus your attention to the Cardiovascular responses above, for Exam 3.

Cardiovascular Adaptations to Endurance Exercise