You take about 20,000 breaths a day, and almost all of them happen without a thought. That is exactly why so many of us breathe inefficiently for years without realizing it.
The BOLT score (Body Oxygen Level Test) is a simple way to gauge how calm and efficient your breathing is. Popularized by Patrick McKeown, author of The Oxygen Advantage, it gives a quick read on your breathing volume and your tolerance to carbon dioxide. In plain terms: is your breathing calm and easy, or fast and heavy? That has a lot to do with how well you sleep and whether you tend to breathe through your mouth at night.
The 60-Second BOLT Test
- Sit comfortably and breathe normally for a few minutes until you feel settled.
- Take a normal breath in through your nose, then a normal breath out.
- After that exhale, pinch your nose closed to hold your breath.
- Count the seconds until you feel the first distinct urge to breathe.
- Release and breathe calmly through your nose again. That number of seconds is your BOLT score.
One rule: stop at the first real urge to breathe, not when you cannot hold any longer. The test measures breathing efficiency, not willpower. Pushing through just gives you a wrong number.
What Your Score Suggests
McKeown's framework gives a rough guide. This is a subjective measure of breathlessness and CO2 tolerance, not a medical diagnosis.
Below 20 seconds
A common starting point. You may notice a blocked nose, snoring, disrupted sleep, daytime tiredness, and getting winded easily. Breathing tends to be heavier than it needs to be.
Around 20 seconds
A typical starting score for someone moderately active. Functional, with real room to make breathing calmer.
Working toward 40 seconds
McKeown describes 40 seconds as the hallmark of efficient breathing, usually paired with a slower breathing rate. It is a goal to work toward over time, not something most people hit at first.
Why It Matters for Sleep
Most sleep advice focuses on hours, not on how you breathe during them. If your breathing is heavy and your mouth falls open at night, your sleep tends to be lighter. Calm, quiet nasal breathing supports the deeper, more restful sleep your body is reaching for.
Improving Your Score Over Time
BOLT scores tend to climb gradually, often a few seconds at a time, as your breathing becomes calmer and more consistent. The simplest foundation is to breathe through your nose as much as possible, day and night. Nasal breathing:
- Adds nitric oxide, which your nose produces and your mouth does not
- Supports a healthier balance of carbon dioxide, which is what the BOLT test reflects
- Filters, warms, and humidifies the air before it reaches your lungs
- Tends to support a calmer, rest-and-recover state
Where Mouth Tape Comes In
If your mouth tends to fall open at night, the hard part is staying nasal once you are asleep. That is what a gentle mouth tape helps with. LullTape keeps your lips together so nasal breathing stays your default through the night, and it comes off cleanly in the morning. Talk to your doctor first if you have or suspect sleep apnea, significant nasal congestion, or a respiratory condition, and do not use it for children.
Your Next Step
Check your BOLT score tonight and write it down. If it lands on the lower end, you know what to work on: nasal breathing, supported by mouth tape while you sleep. Re-test in a few weeks and see where it goes.
The BOLT test was developed and popularized by Patrick McKeown, author of The Oxygen Advantage.
This article is general wellness information, not medical advice.
