Acute Responses

Cardiovascular System By Steph Couper

Inspirational Running Video (HD)

Cardiovascular Responses to Exercise

The Circulatory System works to maintain certain variables at optimal levels in all conditions including rest and exercise. During exercise, the cardiovascular system needs to deliver greater amounts of oxygen and energy substrates to the working muscles, in order to meet the increasing energy demands of the activity.
Heart Beat Animation

Acute Responses

Heart Rate is the number of times the heart beats in one minute.

The faster/ more intense the workout, the higher your heart rate will go. Resting heart rate is anything below 70 beats per minute, you can check this by taking your pulse.
When working out you maximum heart rate should be no more than (220 - your age).


Stroke Volume: Is the amount of blood ejected by the left ventricle per beat. As intensity of the exercise is increased, Stroke Volume increases. When you become fitter your left ventricle increases in size resulting in a larger stroke volume, this then allows for the heart to beat less with the muscles still managing to get the amount of blood needed.


Cardiac Output: is the product of stroke volume and heart rate, therefore the amount of blood pumped out of the heart in one minute. The fitter you are, the lower your cardiac output.


The more you exercise, the healthier your heart will be!

Running Video

The video at the top of this page is a great example of getting the heart beating,

Once the runner gets onto the side of the road his oxygen intake would have increased enough for him to run at a comfortable pace with a steady heart beat.

The heart will be beating a lot faster as the working muscles need more oxygen to function and the only way for them to get that oxygen is via the blood, this is why the heart beats faster during physical activity.

The more the heart beats, the stronger the heart muscles become and the bigger the left ventricle becomes, this is good because it means it can hold more blood, allowing the heart not to beat as fast but to still get the needed amount of blood needed around the body.