Lungs and health

The impact of exercise

Exercise has immediate effects on the respiratory system. It causes an increase in the:

  • breathing rate
  • tidal volume (the volume of air breathed in or out in one breath)

Regular exercise has some additional effects, including an increase in the:

  • strength of the diaphragm and intercostal muscles
  • vital capacity (volume of air that can be forcibly exhaled after inhaling fully)
Woman jogging along a tree-lined path in a park
Exercise has benefits for the respiratory system

Asthma

Asthma affects the bronchioles, the small tubes that carry air in and out of the lungs. If you have asthma your airways can become inflamed, swollen and constricted (narrowed), and excess mucus is produced. More than 5.2 million people in the UK receive treatment for asthma, including 1.1 million children.

During an asthma attack:

  • the lining of the airways becomes inflamed
  • fluid builds up in the airways
  • the muscles around the bronchioles contract, which constricts the airways

The symptoms of an asthma attack include wheezing, a tight chest and difficulty breathing. Symptoms can be treated using asthma relievers. Relievers are drugs that relax and open up the airways, making it easier to breathe. Relievers are often administered using a device called an inhaler. This lets you breathe the medicine in through your mouth, directly into your lungs.

Measuring lung volume

Lung volume can be measured. One way involves a measuring cylinder, marker pen, plastic or rubbing tubing, bowl of water and large plastic container (big enough to contain about 4.5 litres of water). The first job is to calibrate the container:

A man blows into a plastic or rubber tube, the air pushes water out of a plastic container. The volume of water removed from the container is the same as the volume of your lungs.
  1. Use the measuring cylinder to pour a known volume of water into the container, such as 250 cm3.
  2. Mark the water level.
  3. Repeat this process until the container is full.
  4. Half-fill the bowl with water
  5. Fill the container with water and put the lid on. Turn the container upside down and put its neck under the water in the bowl. Take the lid off.
  6. Hold one end of the tubing under the mouth of the container.

To measure a volume, blow through the tubing so that the air pushes water out. After a deep breath, the volume of the water that you expel from the bottle is the same as the volume of your lungs. Read the volume of air produced using your markings.