What is a long-term effect of regular exercise on the heart?

What is a long-term effect of regular exercise on the heart?

• A. Heart becomes more efficient
• B. Resting heart rate increases
• C. Stroke volume decreases at rest
• D. Cardiac output decreases

Answer: (A)

Regular endurance training makes the heart work more efficiently. It causes the heart muscle to become stronger and, often, the left ventricle to adapt so it can pump more blood with each beat. That means stroke volume increases. Because each beat moves more blood, the heart doesn’t need to beat as often to meet the body’s needs at rest, so resting heart rate decreases. In short, the heart becomes better at delivering blood with less effort per beat, which is why this is the long-term effect of regular exercise. The other statements don’t fit the long-term adaptation: resting heart rate would not rise with training, stroke volume at rest does not decrease (it tends to increase), and cardiac output at rest is not generally reduced—if anything, the efficiency allows adequate or improved output during activity while resting values are lower due to the slower heart rate.

Regular endurance training makes the heart work more efficiently. It causes the heart muscle to become stronger and, often, the left ventricle to adapt so it can pump more blood with each beat. That means stroke volume increases. Because each beat moves more blood, the heart doesn’t need to beat as often to meet the body’s needs at rest, so resting heart rate decreases. In short, the heart becomes better at delivering blood with less effort per beat, which is why this is the long-term effect of regular exercise.

The other statements don’t fit the long-term adaptation: resting heart rate would not rise with training, stroke volume at rest does not decrease (it tends to increase), and cardiac output at rest is not generally reduced—if anything, the efficiency allows adequate or improved output during activity while resting values are lower due to the slower heart rate.