The BOLT Score test (Blood Oxygen Level Test) is your key to unlocking valuable insight into your respiratory performance, your tolerance to CO2 as well a helpful indicator of the adaptability of your nervous system. Breathwork is everywhere at the moment and I have studied a number of approaches, but it wasn’t until I studied the Oxygen Advantage approach that I discovered the science behind breathing and how this affects our body and mind. This information is specific and helpful in a practical way that means you can take ownership of your own physiological and psychological performance throughout your day.

 

 

How to do the BOLT score test in 9 easy steps 

Test your breathing efficiency and CO₂ tolerance in just a few minutes

The BOLT (Body Oxygen Level Test) is a quick, science-backed way to assess how efficiently your body uses oxygen—and how well your breathing is supporting your energy, focus, and stress resilience.

Follow these easy steps to measure your BOLT score accurately:

1. Choose a Calm Environment

Find a quiet, comfortable place where you won’t be disturbed.

2. Sit Upright

Sit tall with good posture to allow for natural, unrestricted breathing.

3. Take a Normal Breath In and Out

Breathe in gently through your nose, then exhale naturally through your nose. Don’t empty your lungs forcefully—just a relaxed, normal breath out.

4. Hold Your Breath

After the exhale, pinch your nose to hold your breath. Keep your mouth closed.

5. Start Timing

Begin timing as soon as you hold your breath.

6. Watch for the First Urge to Breathe

When you first feel the urge to breathe—like a tickle in your throat, tightening in your chest, or diaphragm movement—stop the timer.

7. Resume Breathing Naturally

Release your nose and return to a calm, normal breathing rhythm.

8. Record Your Time

The number of seconds you held your breath is your BOLT score.

9. Repeat and Average

Rest for a few minutes, then repeat the test two more times. Take the average of your three scores for the most accurate result.

✅ Tips for a Safe & Accurate BOLT Score Test

To get the most reliable results and perform the BOLT score test safely, keep these tips in mind:

🧘‍♂️ 1. Stay Calm and Relaxed

Perform the test in a quiet space where you feel physically and mentally at ease. Tension or anxiety can affect your breathing and distort results.

🚫 2. Stop if You Feel Dizzy

If you experience lightheadedness, dizziness, or discomfort, stop immediately and resume normal breathing. Never force the breath hold.

⏳ 3. Build Comfort Over Time

Start with gentle breath holds and gradually extend the duration as your CO₂ tolerance improves. This is not a maximum-hold test—it’s about the first urge to breathe.

🌅 4. Test First Thing in the Morning

For consistency, perform the test in the morning on an empty stomach, before caffeine or intense activity. This gives a clearer baseline for comparison over time.

📈 5. Be Patient and Consistent

BOLT scores vary between individuals and can fluctuate throughout the day. The key to improvement is regular practice, not perfection. Breathing retraining, nasal breathing, and stress reduction techniques can significantly improve your score over time.

🧠 Your BOLT score is a reflection of your breathing health today—not your potential. With consistency, you’ll see steady gains in your oxygen efficiency and overall well-being.

🫁 What Your BOLT Score Tells You

Understanding your breath-hold time and what it means for your health

The BOLT Score (Body Oxygen Level Test) reflects how long you can comfortably hold your breath after a normal exhalation. It offers insight into your carbon dioxide tolerance, nervous system regulation, and overall breathing efficiency.

Here’s what your score reveals:

🟥 Less than 10 seconds

Low CO₂ tolerance & poor breathing efficiency

• Likely linked to chronic stress or dysfunctional breathing habits

• May indicate over-breathing or stress or anxiety susceptibility

• High potential for improvement with consistent breathwork

🟧 10–20 seconds

Moderate breath control

• Indicates average respiratory function

• Room to improve oxygen delivery and resilience

• Breathing may still be too shallow or irregular under stress

🟨 20–40 seconds

Good breathing efficiency

• Solid CO₂ tolerance and more stable breathing patterns

• Supports better energy, endurance, and stress regulation

• Reflects healthy respiratory control

🟩 40 seconds or more

Excellent breath-holding capacity

• High-functioning respiratory and nervous systems

• Optimised oxygen delivery and strong CO₂ tolerance

• Indicates resilience, calm under pressure, and peak performance potential

Now you know your score, read this post about how to improve it and what this means for your performance and wellbeing: What is the BOLT Score and How to Improve it