Why Does Fresh Air Make You Tired?

Getting outside is a key part of a healthy lifestyle – a walk in the park, a hike through the woods, or a day by the sea can do wonders for your mood and energy. But have you ever noticed that after spending time in the fresh air you feel unusually sleepy? Many people find that an open window or a few hours outdoors leaves them more relaxed and ready for a nap.

While some of this can be chalked up to the obvious, like physical activity or a break from screens, there’s also some fascinating science behind why fresh air, and particularly sea air, has such a powerful effect on our relaxation. Let’s take a closer look…

Fresh air typically contains higher levels of oxygen compared to indoor air. This increased oxygen can promote better blood circulation and support healthier brain function, helping you feel calmer, more clear-headed, and ultimately more ready for sleep.

Your temperature naturally drops when you start to fall asleep, so a nice, cool breeze may help you feel sleepy. This is all due to our circadian rhythm, the biological clock that helps us wake and sleep.

Quite simply, this internal clock requires signals to keep it in tune. One of those signals is a slight drop in temperature. Now, whether our bodies cool down because they know we’re about to sleep, or whether cooling down is what helps us fall asleep in the first place, doesn’t really matter. Science shows that we need to cool down to allow us to drift off. Clearly, allowing fresh air into a hot or humid bedroom can help.

Find out more about the best temperature for sleep.

Getting at least 30 minutes of exercise during the day has lots of benefits for your health, including helping you sleep. Even just going for a walk can improve your mood and cardiovascular health while burning off energy.

And similar to body temperature, exercise also regulates our circadian rhythm, improving our ability to fall asleep. Learn more about this in our article on how sleep and exercise are linked.

Fresh air, especially in quiet green spaces such as parks, can lower the stress hormone cortisol. When you’re in a calm environment breathing clean air, your heart rate naturally slows, decreasing muscle tension, and your breathing becomes deeper and slower. This shift signals the body to reduce stress and anxiety.

Furthermore, as mentioned before, fresh air contains higher oxygen levels, which can support hormone regulation. The natural surroundings can also soothe your mind, triggering relaxation.

Learn about how you can sleep when you’re stressed.

Indoor air can be stale, low in oxygen, and high in carbon dioxide, especially in poorly ventilated bedrooms. Elevated levels of carbon dioxide are linked to poor sleep quality and next-day grogginess. Opening the windows to let fresh air in can dilute this carbon dioxide, improving overall air quality and leading to more restful, deep sleep.

Good airflow helps limit the amount of allergens in the air. As allergies can result in symptoms like difficulty breathing and general discomfort, reducing their presence in our bedrooms is key to a good night’s rest.

One of the most common allergies is dust mites, which feed on, you guessed it, dust! Household dust is actually made up of a (pretty gross) combination of fine dirt, skin, clothes fibres, and hair. Regular cleaning and good ventilation will help reduce the dust in your home and how much it irritates you, especially while you sleep. Of course, hay fever is prominent too, and you’ll want to limit open windows in this case. Check out our article for more on how to sleep with hay fever.

Fresh air means exposure to natural light, which is key to regulating your body clock and melatonin production. Light during the day can suppress melatonin, which helps you feel alert. As light fades, the production kicks in, increasing feelings of sleepiness.

If you’ve ever found yourself yawning on a seaside stroll or drifting off more easily to the sound of waves, you’re not alone. For centuries, doctors prescribed seaside visits as a tonic for everything from anxiety to fatigue, but was there any truth to this old-fashioned remedy?

Surprisingly, yes, sea air can make you tired. Here’s why:

• Sea air contains negative ions, which can help balance serotonin levels and reduce stress.
• The cool, salty breeze can encourage deeper breathing, calming your nervous system.
• The rhythmic sound of lapping waves is a soothing form of pink noise, which has been shown to promote stable sleep cycles.

While there isn’t any scientific evidence that sea air is better for you than inland air, many people feel sleepier and more relaxed by the coast. And even living by the sea can impact your quality of life.

Speaking to Blue Health, Dr Lewis Elliot explains why those near the coast typically live longer and are happier: “My interpretation is that there are more opportunities for physical activity and stress reduction by the coast that don’t exist inland.”

People who live by the coast are more likely to engage in activities like swimming, surfing, and sailing. Other factors include proximity to nature, separation from urban stress, and eating fresh, local produce.

For some people, sleeping with the window open is essential, and for others, it’s a deal breaker. But is there scientific backing either way?

Ultimately, the same benefits of fresh air exist for sleeping with open windows. It can help keep you cool, bring in more oxygenated air, and reduce potential irritants like dust. However, some barriers to a good night’s sleep can exist, such as bad weather and noise. So, while fresh air can be good for you overnight, it doesn’t outweigh disturbances that keep you up.

If your home lacks good airflow, it can be a bigger problem than you first imagined. Here are some of the most common issues to look out for:

• Humidity: As warm-blooded creatures, we give off heat and moisture daily. However, too much water in the air can make breathing harder and cause issues like sore throats.
• Mould: Dampness can also cause mould to grow, which can cause skin irritation, respiratory issues, and general feelings of unwellness. The NHS has guidance on mould poisoning, its causes, and how to spot it.
• Carbon dioxide build-up: We inhale oxygen and exhale CO2, so it’s imperative that you have a good flow of fresh air to dispel the carbon dioxide and bring you more oxygen.
• Odours: Bad smells happen, especially when fresh air doesn’t come in. Over time, you might become unaware of odours in your home, but it’s important to keep it clean and fresh for your mental and physical well-being.

Here are a few tips on how to give your bedroom a refresh with or without the window closed:

1. Dehumidifiers

Without fresh air coming in, you may want to find a way to reduce humidity indoors. This is especially important during winter when body heat, central heating, and the cold all battle it out and cause condensation. A dehumidifier will remove water from the air and make things more comfortable while also reducing the risk of mould.

2. Essential oils

If you want to freshen things up without leaving a window open, essential oils can help. Scents like mint, lavender, and eucalyptus are bright and invigorating. You can always change to oils and scents that help you sleep just before bed.

3. House plants

Bringing nature indoors can be the answer if you don’t have access to a garden. Alongside the broader benefits of nature for sleep, some house plants like Aloe Vera and African Jasmine help re-oxygenate the bedroom. Take a look at the best plants to help you sleep and revitalise your space.

All in all, if you’re struggling to sleep at night, it’s worth considering how much fresh air you allow into your room and how much time you spend outdoors during the day. In one way or another, the benefits are all linked to improving your sleep quality.