Planning a morning run, a family walk or a weekend bike ride? Checking the weather is probably already part of your routine. But there's another forecast worth checking: air quality.
In most cases, Low or Moderate air pollution doesn't mean you need to stay indoors. However, when pollution reaches High or Very High levels, reducing strenuous outdoor activity can help limit exposure, particularly if you have a lung or heart condition.
In the UK, air pollution is communicated using the Daily Air Quality Index (DAQI). Here's what the different levels mean and how they can affect walking, running, cycling and other outdoor activities.
Quick Guide to the UK Air Quality Index
|
DAQI |
Pollution level |
What should you do? |
|
1–3 |
Low |
Most people can enjoy their usual outdoor activities. |
|
4–6 |
Moderate |
Most people can continue normal activities. |
|
7–9 |
High |
If you experience symptoms, consider reducing activity, particularly outdoors. |
|
10 |
Very High |
Reduce physical exertion, particularly outdoors. People with lung or heart conditions and older people should avoid strenuous activity. |
What Is an Air Quality Alert?
An air-quality alert or forecast warns you when pollution levels are elevated or expected to rise.
The DAQI is the UK's scale for communicating short-term air-pollution risk. It runs from 1 to 10 and is divided into four bands:
- Low: 1–3
- Moderate: 4–6
- High: 7–9
- Very High: 10
The index takes several pollutants into account, including particulate matter (PM2.5 and PM10), nitrogen dioxide, ozone and sulphur dioxide.
An air-quality alert warns you when pollution levels are elevated or expected to rise. The Daily Air Quality Index (DAQI) then helps communicate the short-term health risk using a 1–10 scale.
A higher DAQI doesn't automatically mean everyone needs to stay indoors. The appropriate response depends on the pollution level, your health and whether you develop symptoms.
What Does Each DAQI Level Mean?
DAQI 1–3: Low
For most people, short-term exposure to low levels of air pollution isn't an issue, so you can continue your usual outdoor activities. However, some people may experience symptoms even when pollution levels are low. Adults and children with lung or heart conditions should follow their healthcare professional's advice and any agreed management plan, such as an asthma action plan.
DAQI 4–6: Moderate
For most people, short-term exposure to moderate pollution isn't an issue and usual outdoor activities can continue. If you develop symptoms, try to reduce your exposure and speak to your doctor or nurse if symptoms are new, worsen or don't improve within a week.
People with lung or heart conditions: Consider adapting physically demanding outdoor activities, particularly if symptoms get worse, and follow your agreed management plan.
DAQI 7–9: High & DAQI 10: Very High
At High and Very High pollution levels, try to reduce your exposure to air pollution, particularly if you're experiencing symptoms. Adults and children with lung or heart conditions, as well as older people, should adapt physically demanding outdoor activities, especially if symptoms worsen.
Continue to follow any agreed management plan, such as an asthma action plan, and speak to a healthcare professional if you develop new or worsening symptoms or they don't improve within a week.
These recommendations are based on current UK Government DAQI health advice.
Remember that air pollution isn't the only possible trigger. High pollen levels and poor indoor air quality can also contribute to symptoms.
Can You Exercise When Air Quality Is Poor?
Yes, sometimes—but it depends on the DAQI level, your health and the intensity of the activity.
When you exercise, you generally breathe faster and more deeply, which can increase the amount of polluted air you inhale.
At Low and Moderate levels, most people can continue normal activities. At High or Very High levels, consider reducing strenuous outdoor exercise or moving your workout indoors.
If you planned a hard workout but the air-quality level is high, you could:
- Exercise indoors
- Choose a gentler activity
- Reduce the duration or intensity
- Wait until air quality improves
The aim isn't necessarily to stop being active. It's to reduce unnecessary exposure when pollution is elevated.
Can You Run When Air Quality Is Poor?
Running is relatively strenuous, so checking air quality before heading out is worthwhile.
At Low and Moderate levels, most people can run as usual. At High or Very High levels, consider reducing the intensity or moving your run indoors, particularly if you have asthma, COPD, heart disease or another condition affected by air pollution.
If running suddenly feels much harder than usual on a poor-air-quality day, don't simply push through it. Check the air quality, reduce the intensity and pay attention to your symptoms.
What About Walking and Cycling?
Walking is generally less strenuous than running, but your exposure still depends on pollution levels, how long you're outside and where you are.
Cycling, particularly at speed or for long periods, can increase your breathing rate and exposure.
When pollution levels are higher:
- Choose less strenuous routes where possible.
- Avoid spending unnecessary time near busy roads.
- Consider a shorter or slower activity.
- Check the air-quality forecast before setting off.
- If you develop symptoms, reduce your outdoor activity.
People with asthma or other lung conditions should follow their individual medical advice.
Does the Time of Day Affect Air Quality?
Sometimes. Air pollution can change throughout the day depending on weather, sunlight, wind and local emissions.
Rather than assuming morning or evening is always better, check the local air-quality forecast before exercising.
DEFRA's air-quality services provide forecasts that can help you plan outdoor activities around expected pollution levels.
How to Check Air Quality in the UK
The UK Government's air-quality services provide local forecasts, measurements and health advice.
You can check the DAQI to see whether pollution is Low, Moderate, High or Very High in your area.
The UK-AIR website is also being replaced by newer government services, so use the current Check air quality service for local forecasts rather than relying on an old bookmark.
It's particularly useful to check air quality before:
- A long run
- Outdoor sports
- Cycling
- Hiking
- Gardening
- Outdoor work
- A children's sports event
What Should You Do When an Air Quality Alert Is Issued?
Don't automatically assume you need to cancel your plans. Instead:
-
Check the DAQI.
Find out whether pollution is Low, Moderate, High or Very High. -
Consider your health.
People with lung or heart conditions and older adults may need to take extra precautions. -
Think about the activity.
A gentle walk is different from a hard run or intense outdoor workout. -
Watch for symptoms.
Coughing, sore eyes, sore throat or breathing difficulties can be a reason to reduce outdoor activity. -
Adjust your plans if necessary.
Move your workout indoors, reduce its intensity or wait for conditions to improve.
Who Is More Sensitive to Air Pollution?
Some people are more likely to experience health effects when pollution rises, including:
- Adults and children with lung conditions
- Adults with heart conditions
- Older people
If you have asthma or another respiratory condition, follow your personalised management or action plan and take prescribed medication as directed. Don't change your treatment based solely on an air-quality reading without advice from your healthcare professional.
What Are the Symptoms of Air Pollution Exposure?
Short-term exposure to air pollution can cause symptoms such as:
- Coughing
- Chest tightness or discomfort
- Difficulty breathing
- Eye, nose or throat irritation
- Worsening asthma symptoms
- Worsening COPD symptoms
Symptoms can begin within hours or several days after exposure. If you develop new or worsening symptoms, reduce your exposure and seek medical advice if they persist or become concerning.
If you have severe difficulty breathing or another medical emergency, seek urgent medical help.
Can Portable Oxygen Help When Air Quality Is Poor?
When air quality is poor, the best approach is to limit exposure and follow official health advice. Portable oxygen canisters, such as Boost Oxygen, offer a convenient source of concentrated oxygen for recreational use. However, they should not be used as a treatment for air pollution or wildfire smoke exposure, or as a replacement for clean air or prescribed medical oxygen. Always follow the product instructions and keep oxygen products away from flames, smoking and other ignition sources.
Final Thoughts
An air-quality alert doesn't necessarily mean you have to cancel your plans. What matters is understanding what the DAQI level means and adjusting your activity accordingly.
For most people, Low and Moderate pollution levels don't require major changes to normal outdoor activities. At High or Very High levels, reducing strenuous outdoor exercise becomes more important, especially if you have a condition that makes you more sensitive to air pollution or you're experiencing symptoms.
Before your next run, cycle or long walk, check the air-quality forecast alongside the weather. A few seconds of preparation can help you make a smarter decision about when, where and how intensely to exercise.
