Clear the Air - a novel way to enhance sleep and performance

Last week’s blog post focused on why sleeping on our sides is generally preferable to back-sleeping, and also practical steps that help keep us from rolling onto our backs during the night. This week, I want to focus on another factor that can have a perhaps surprising impact on sleep quality – the air that we breathe through the night.

It is well known that a build-up of the gas carbon dioxide in our immediate environment can cause our surroundings to feel ‘airless’ and ‘stuffy’, and there is even some evidence which shows that not allowing carbon dioxide to build up in the immediate work environment can help with a range of cognitive functions. Could, then, carbon dioxide levels in the bedroom affect sleep quality?

In one study [1], compared to an average carbon dioxide concentration of 660 parts per million (ppm), a concentration of 2,585 ppm led to a worsening in objective measures of sleep, as well as impaired concentration and the ability to think logically the following day.

I track my sleep, and can attest to the impact carbon dioxide has on sleep. If I sleep in a room in which carbon dioxide levels have been allowed to build up during the night, I see an impact on sleep quality and ‘recovery’ (for example, my resting heart rate is higher).

As a general rule, I recommend carbon dioxide concentrations to be kept below 1,000 ppm in our immediate surroundings.

I’ve experimented with this a lot. What I’ve found is that in a room (home office, bedroom) where windows and doors are shut, carbon dioxide levels can climb to well over 1,000 ppm (and sometimes significantly more than 2,000 ppm) within a few minutes.

However, even a little ventilation will generally keep levels of carbon dioxide below 1,000 ppm. What I’ve found most effective here is for there to be a way for air to flow through a room by having two openings on either side of the room.

This is not always possible. For example, a couple of weeks back, I was on a speaking engagement in Copenhagen. Due to a delayed flight, I did not arrive at my hotel until about 3.00 am local time. Nevertheless, the first thing I did once I got into my room was crack open the window and leave the curtains somewhat apart. Other than leaving the door to my room ajar (perhaps not advisable), there was no way of allowing air to flow through the room. But, having at least one source of fresh air into the room is a lot better than nothing, I've found.

My approach regarding the windows and curtains made my hotel room significantly noisier (road noise) and lighter (street lights). However, eyeshades and earplugs – I never travel without them – saw to that.

When at home, I use a device made by a company called Netatmo (I have no affiliation with the company) called the ‘Home Coach’ for monitoring carbon dioxide levels via an app, though other similar devices are available. This is what allows me to be sure the set-ups in my bedroom and home office work to keep carbon dioxide levels well under the 1,000 ppm mark.

To my mind, air quality is an important but under-recognised determinant of sleep quality and wellbeing. Cracking open a window or two can be all it takes for you to feel the benefit.

If you feel this information would help someone else in your team or company as a whole, please feel free to pass on!

References:

1. Strøm-Tejsen P, et al. The effects of bedroom air quality on sleep and next-day performance. Indoor Air. 2016;26(5):679-86