How is Blood Flow Related to Lung Function during Exercise?

By Jessica Kelley | Health


How is Blood Flow Related to Lung Function during Exercise?

Most of us know that exercise is good for the body. However, when we truly understand how it changes the body, it would become easier for us to get out of bed and get it going.

The body is a complex machine and there are quite a few changes that take place when you start working out. One of these changes is that we tend to breathe faster than usual when we workout.

This change has prompted many people to ask how blood flow is related to lung function during exercise.

The Pulmonary Circulation

The pulmonary circulation is a considered a low pressure and high flow circuit. The low-pressure aspect of this circulation prevents the fluid from moving out from the pulmonary vessels towards the interstitial spaces, allowing the right ventricle to function and operate at a relatively minimal energy cost.

When you exercise, your oxygen uptake and carbon dioxide output are both increased. This increase in gas exchange is linked to an increase in cardiac output.

The increase in cardiac output is essential for the increased transport demands of oxygen to and from the exercising muscles.

It can be noted the exercise actually places a considerable amount of stress on the pulmonary circulation. Basically, it takes the entire cardiac output while keeping the right ventricle well compensated and the lungs dry.

The primary goal of both the heart and lungs during exercise is to ensure that there is ample supply of oxygenated blood. Oxygen is essential in producing the energy which is necessary sustain activity.

Increased Heart Rate


During running or exercise, the heart responds by increasing the number of contractions every minute. When at rest, heart rate can increase from 60 beats per minute to 100 beats per minute.

When you exercise, however, your heart rate can increase up to 200 beats per minute depending on your gender, age, and fitness level.

Through increasing the number of beats per minute, the heart is able to supply the body with the larger amount of blood when exercising.

Stroke Volume

The stroke volume is the amount of blood that your heart pumps out towards the other parts of your body every time it beats.

To fulfill the need for additional blood supply during exercise, the stroke volume also increases.

At resting rate, the stroke volume can increase by 40 percent to 60 percent. As more blood returns to the heart, the ventricles will be filled with a greater amount of blood.

This return process allows for the optimal stretch in the cardiac muscles, resulting to more blood ejected and stronger heartbeats.

The Tidal Volume

The lungs also increase their work during exercise and workout. This increase is important to ensure that there is ample supply of both carbon dioxide, and oxygen, during exercise.

At rest, the lungs can move up to 6 liters of air per minute. However, during maximal exercise, the lungs can move up to 192 liters of air every minute.

The increase in tidal volume means that the respiratory rate can increase from 12 breaths per minute while at rest to 48 breaths per minute during exercise.

Respiratory Muscles

To increase the frequency of breaths and air movement, the lungs are equipped with certain expiratory and inspiratory muscles.

When at rest, the intercostal muscles and the diaphragm open up the lungs so air can be forced in. Exhalation is considered a passive function that is performed without the use of any muscle force.

During exercise, the accessory inspiratory muscles help during the inspiration process and at the same time exhalation process becomes a forceful action.

The other muscles, namely trapezius, scalene, and sternocleidomastoid muscles will also work to ensure that more air is brought into the lungs.

During exhalation, both the abdominal muscles and intercostal muscles work to force air out of the lungs. This action effectively expels carbon dioxide.

Proper Breathing during Exercise


Breathing properly is an important part of exercising. When you breathe properly and effectively when you exercise, you are not only ensuring that your exercising muscles are getting sufficient oxygen but you are also providing other benefits to your body.

For instance, when you breathe properly, you are actually ensuring that you maintain proper posture even when you are working out. During inhalation, your chest expands while keeping your back straight.

Also, when you have proper posture during exercise, there is less risk for injuries.

Breathing properly during exercise or workout can also help improve your overall body performance, boost your body’s fat burning capabilities, and enhance your metabolism.

During exhalation, both the abdominal muscles and intercostal muscles work to force air out of the lungs. This action effectively expels carbon dioxide.

Nasal Breathing versus Mouth Breathing

Both children and adults have the tendency to breathe through the mouth instead of breathing through the nose. Whether you are sleeping or exercising, it is always ideal to breathe through the nose.

When you breathe through your mouth, your brain will think that carbon dioxide is leaving the body at a faster rate. Thus, it will stimulate the production of mucus to slow your breathing. Also, this breathing technique can result to hyperventilation.

On the other hand, breathing through the nose is considered more efficient in supplying oxygen throughout the body.

When you breathe through your nose when you exercise, you will not only get sufficient supply of oxygen but also the air you breathe is properly filtered and warmed.

Nasal breathing is more efficient as there is an increased percentage of oxygen extracted from the air by the lungs during expiration and an increase in the percentage of carbon dioxide in the expired air.


Via StyleCraze


The lungs and the heart work hand in hand in ensuring that your body gets ample supply of oxygen during exercise.

Your heart pumps at a rapid rate so the supply of oxygen is efficiently distributed throughout the body, especially on the exercising muscles.

On the other hand, the lungs respond by increasing the number of breaths per minute and promoting a more powerful lung function.

 Such response is essential in ensuring that there sufficient amounts of oxygen extracted from inhaled air and large amounts of carbon dioxide expelled through exhalation.

It is, however, important to note that proper breathing technique is followed when exercising. Nasal breathing will help improve performance, promote fat burning capabilities, and boost oxygen intake and carbon dioxide expulsion.


About the Author

I am Jessica, co-founder of We work to inspire, educate and empower our readers with all the latest updates and authentic information. Our goal is to bring up the “Healthy attitude” among people in the world. On you will find high-quality health information, fitness tips, diet charts and answer to all your health queries.

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