Stroke volume (SV) is the amount of blood ejected by the left ventricle during a contraction. It is measured in mL/beat. A substantial increase in SV is a long-term effect of endurance training.
In other words, stroke volume is notably higher at maximal exercise following an endurance training program. This occurs because training causes the left ventricle to fill more completely during diastole (the relaxation phase of cardiac contraction) than it does in an untrained heart. There is also more blood in circulation following training as a consequence of an increase in blood plasma volume. This means that more blood is able to enter the ventricle. In fact, blood volume can increase by half a litre after only eight days of endurance training. This results in a further stretch by the ventricular wall which increases the elastic recoil of the chamber. The enlarged ventricle enables contractions that are more powerful, resulting in less blood remaining in the ventricles following systole.
The ability of the body to make oxygen-rich blood available for working muscles is the biggest factor affecting aerobic performance. The more blood that the heart can eject per heart beat, the more work an individual will be able to do.
Aerobic training, over a period of time, has a substantial effect on stroke volume and, therefore, on the individual's future aerobic performance. Training causes the size of the heart to increase, noticeably, the ventricles. The walls of the ventricles also become thicker and stronger. This allows for more blood to enter the heart and more powerful contractions and therefore more blood to be ejected during each contraction.
For all heart rate levels, from rest to maximal exercise, training increases an individual's stroke volume and this is more evident during sub-maximal and maximal exercise as the ventricle fills more completely.
The increased oxygen available to the working muscles results in improved performance.
In other words, stroke volume is notably higher at maximal exercise following an endurance training program. This occurs because training causes the left ventricle to fill more completely during diastole (the relaxation phase of cardiac contraction) than it does in an untrained heart. There is also more blood in circulation following training as a consequence of an increase in blood plasma volume. This means that more blood is able to enter the ventricle. In fact, blood volume can increase by half a litre after only eight days of endurance training. This results in a further stretch by the ventricular wall which increases the elastic recoil of the chamber. The enlarged ventricle enables contractions that are more powerful, resulting in less blood remaining in the ventricles following systole.
The ability of the body to make oxygen-rich blood available for working muscles is the biggest factor affecting aerobic performance. The more blood that the heart can eject per heart beat, the more work an individual will be able to do.
Aerobic training, over a period of time, has a substantial effect on stroke volume and, therefore, on the individual's future aerobic performance. Training causes the size of the heart to increase, noticeably, the ventricles. The walls of the ventricles also become thicker and stronger. This allows for more blood to enter the heart and more powerful contractions and therefore more blood to be ejected during each contraction.
For all heart rate levels, from rest to maximal exercise, training increases an individual's stroke volume and this is more evident during sub-maximal and maximal exercise as the ventricle fills more completely.
The increased oxygen available to the working muscles results in improved performance.