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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 |
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| NOTE: If the following chart is not discussed in any lecture during the metabolic and cardiovascular lectures, it will NOT be on the exam! |
Cardiovascular Adaptations to Endurance Exercise
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