impact of physical activity and sport on fitness Flashcards
What is stroke volume?
Stroke volume is the volume of blood pumped out by the heart ventricles in each contraction. On average, the resting stroke volume is approximately 70ml.
What factors increase stroke volume?
Stroke volume increases due to venous return, the elasticity of cardiac fibres, and the contractility of cardiac tissue.
How does venous return affect stroke volume?
When venous return increases, stroke volume also increases.
What is the role of cardiac fibre elasticity in stroke volume?
The elasticity of cardiac fibres relates to the degree of stretch of cardiac tissue during diastole; greater stretch results in a greater force of contraction, greater stroke volume
How does contractility affect stroke volume?
The greater the contractility of cardiac tissue, the greater the force of contraction.
How does stroke volume respond to exercise?
Stroke volume increases as exercise intensity increases, up to 40-60 percent of maximum effort, after which it plateaus.
What is heart rate?
Heart rate refers to the number of times the heart beats per minute. On average, the resting heart rate is approximately 72 beats per minute.
How does heart rate change in response to exercise?
Heart rate increases with exercise, in direct proportion to exercise intensity; the higher the intensity, the higher the heart rate.
What happens to heart rate at maximum effort?
Heart rate eventually reaches a maximum.
What is the maximum heart rate formula?
Maximum heart rate is calculated as 220 minus age.
What happens to heart rate during maximal exercise?
Heart rate shows an anticipatory rise due to hormonal action, followed by a sharp rise due to anaerobic work and continues to rise due to maximal workloads.
What is cardiac hypertrophy?
Cardiac hypertrophy is when the heart becomes bigger and stronger due to a thickening of the muscular wall.
What is bradycardia?
Bradycardia is when there is a decrease in resting heart rate to below 60 beats per minute.
What is cardiac output?
Cardiac output is the volume of blood pumped out by the heart ventricles per minute, calculated as stroke volume (SV) × heart rate (HR).
How does cardiac output respond to exercise?
During exercise, cardiac output increases due to an increase in heart rate and stroke volume, plateauing at maximum intensity.
