How healthy are your lungs? Improve lung health with these simple steps

The powerhouse organs work around the clock to supply your body with life-giving oxygen. But their strength typically declines from your mid-20s. Here’s how you can check your lung capacity and improve lung function

To maximise life expectancy and healthspan, we should achieve the best possible lung function during childhood and adolescence, for example, through regular physical activity.

The winter is the most challenging season for our lungs, a time when they are bombarded with infections.

Ireland had a covid surge in September and October with more than 500 cases per week, says the Health Protection Surveillance Centre. And seasonal flu is on the rise, with 200 weekly infections and 53 hospitalisations.

People with persistent lung conditions, such as asthma and chronic obstructive pulmonary disease (COPD), are particularly vulnerable to such infections, as their respiratory function is already impaired.

In Ireland, chronic respiratory disease accounts for 13% of all deaths, while 500,000 people are living with some form of long-term lung impairment, many of whom are undiagnosed.

Such respiratory conditions also become more common with age, because our lungs peak surprisingly early in life, probably in our mid-20s, according to a study this year that analysed data from more than 30,000 men and women.

“Your lung function hits maturity at about age 25, and then you see this very slow, annual decline after that,” says Professor Seamus Linnane, deputy medical director of Beacon Hospital, and a consultant in respiratory and general internal medicine.

In Ireland, chronic respiratory disease accounts for 13% of all deaths, while 500,000 people are living with some form of long-term lung impairment, many of whom are undiagnosed. Picture: iStock.

The findings have led scientists to two conclusions. Firstly, to maximise life expectancy and healthspan, we should achieve the best possible lung function during childhood and adolescence, for example, through regular physical activity.

Secondly, it’s essential to slow this inevitable decline as much as possible. Research has repeatedly shown that lung function throughout adulthood is indelibly linked to longevity. This is because worsening lung health is not only associated with respiratory disease and greater vulnerability to infection, but it’s linked to cardiovascular disease because of the close connection between the lungs and heart. The lungs filter the blood pumped from the right side of the heart, before returning it to the left side to be sent out around the body.

Because the lungs are so interconnected with the body, declining lung function is also associated with a range of conditions, including autoimmune diseases, frailty, metabolic disorders, and even cognitive decline.

“The lungs don’t work in isolation,” says Adam Byrne, professor of respiratory immunology at University College Dublin School of Medicine.

“They’re deeply connected to the heart, immune, and metabolic systems. When the lungs are under strain, that stress can ripple through the body, driving broader systemic effects.

“In that sense, lung capacity can act as a window into how well we’re ageing.”

Your lung age

There are obvious signs of lung ageing, whether that’s increased breathlessness during a particular activity, wheezing, or, in even more serious instances, chest pains.

However, while these symptoms only tend to become obvious when lung decline has reached a more advanced stage, Linnane says that the wearables and home-health-testing markets are making it possible for people to assess subtler and more helpful information about how their lungs are ageing, without needing to undergo a detailed analysis in a clinical lung-function laboratory.

One key metric of lung age that anyone can monitor with a typical smartwatch is VO2 max, which stands for maximal oxygen uptake. “VO2 max tells you the absolute maximum oxygen you can take in from your environment through your breathing, and then have available to undertake exercise,” he says. “That’s a very good measure of lung function, capacity, and also general health.”

VO2 max declines with age, due to a loss of elasticity in lung tissue, a weakening of respiratory muscles (like the diaphragm), and changes in the rib cage, inhibiting its ability to expand and contract, but maintaining lung capacity as much as possible has been strongly linked to how long you’re likely to live.

The same is true for forced expiratory volume (FEV1), or the amount of air you can exhale in litres in one second after taking a deep breath. This can be measured by a device called a spirometer, which can be purchased for between €15 and €25.

“We know that people who have a low FEV1 compared with people of the same age, height, and gender tend to have more vascular disease, more heart attacks, and more unexpected illnesses,” says Linnane.

“Studies have shown that there’s a survival advantage to having a higher FEV1.”

A spirometer can also measure your forced vital capacity (FVC) or the highest amount of air you can blow out after taking a deep breath.

Doctors first noticed, as early as the 1840s, that people with a low forced vital capacity had a shorter life expectancy, and according to the American Lung Association, FVC can decrease by 0.2 litres per decade, even in healthy non-smokers.

Population research indicates that a normal, healthy FVC is between three and five litres.

While we can get useful information from such measurements and see whether our lungs are ageing faster or slower than expected compared to others of a similar age, Linnane says that it’s key to take these tests repeatedly, for example, once a year.

Tracking whether the results remain stable or decline can provide a relatively accurate assessment of your overall health.

“Let’s say I’m blowing five litres at the beginning of the year, and I’m only able to blow four litres [at the end of the year],” he says. “That reflects a notable deterioration.”

Improving lung health

When it comes to lung ageing, Linnane says that the most important thing is to try and protect your current level of function as much as possible, and also follow public health advice by stopping smoking.

Getting vaccinated can also be a powerful way to protect lung health. “The lungs are incredibly intricate, delicate structures,” Linnane says. 

“So to keep them healthy, it’s following the advice around stopping smoking, and trying to avoid seasonal infections as much as you can. Everyone gets a cold each year. Some of that you can’t avoid, but repeated infections can damage lung function over time.”

However, some factors that impair lung health are also unavoidable, particularly airborne pollutants.

The Environmental Protection Agency has found that poor air quality in major cities, resulting from microscopic particles emitted by factories and vehicle exhaust, contributes to 1,300 premature deaths annually.

So if your lungs are ageing faster than they should, what can you do about it? Byrne says that exercise, as a form of positive stress to the body, is extremely beneficial, along with other activities focused on breath control.

“Staying active is one of the best ways to slow that decline,” he says.

“Regular aerobic exercise, even brisk walking, can help strengthen the muscles involved in breathing and keep airways flexible. Activities that encourage deep, controlled breathing, like swimming, singing, or yoga, can also help.

If your lungs are ageing faster than they should, what can you do about it? Byrne says that exercise, as a form of positive stress to the body, is extremely beneficial.

“While you can’t ‘grow’ new lung tissue, you can certainly make your existing lungs work more efficiently.”

There are also special lung-training exercises, such as learning diaphragmatic breathing or pursed-lip breathing, which teach the body to take slower, deeper breaths and improve oxygen exchange.

Since the mid-1990s, inspiratory muscle training (IMT) — which involves training the respiratory muscles by blowing against a resistance using a medical device called POWERbreathe — has become known as a way to boost lung function in a range of people, from athletes to singers, who have lung conditions such as COPD.

IMT can strengthen the various muscle groups that support the lungs, such as the diaphragm and intercostal muscles, increasing a person’s breathing capacity.

Studies have shown that two 30-breath IMT sessions per day can boost the strength of these muscle groups.

Another way of improving our ability to utilise our respiratory muscles and help our lungs better pump air around the body is to take up singing or play a wind instrument.

At the University of Southern Denmark, researchers are studying how singing might help people with COPD, while other scientists have examined how improving breath control, by playing instruments like the flute, can boost the lung function of people living with asthma.

We can also take steps to mitigate age-related lung function decline through less obvious measures, such as better diet. Less salt and more fish oils, as well as vitamins C and E, can protect the lung walls from damage.

“We know that when these things are optimal, your lungs will perform at their best,” says Linnane.

“But the most important thing of all is to try to keep to a weight where you can pursue active physical activity on a regular basis, as that stimulation keeps your lungs working as efficiently as they can.”

Assess your lung capacity at home

Want to estimate your lung capacity (in litres)? Here's a simple DIY test. 

You will need:

• Large plastic bottle
• Bucket
• length of rubber tubing.

How to do the test:

• Measure out 200ml of water into a measuring jug, then transfer it to the plastic bottle and use a pen to mark the water level.
• Repeat this process until the bottle is full.

Partially fill the bucket with water, and place your hand over the top of the full plastic bottle. Turn it upside down under the water.

Keeping the top of the bottle submerged, place one end of the rubber tubing inside the bottle neck.  It doesn't have to fit tightly. 

Take a deep breath and blow as hard as you can into the tube. 

Count how many lines of water you can blow out of the bottle. 

Multiply the number of lines by 200ml. This number is your forced vital capacity (FVC). 

Note: This is not a medical test. Please chat with your doctor if you are concerned about your lung capacity.