Optimise Your Breathing: Why Your BOLT Score Matters and How to Improve It

When it comes to improving well-being and physical performance, the BOLT score (Body Oxygen Level Test) is a simple yet powerful metric. It offers valuable insight into your respiratory efficiency, carbon dioxide (CO₂) tolerance, nervous system regulation, and oxygen delivery capacity—all crucial for energy, resilience, and long-term health.

In this post, I’ll explain what the BOLT score is, why it’s so important, and how you can improve it with practical, science-backed strategies.

If you haven’t yet measured your BOLT score, you can learn how to do that and undertand its meaning here.

What Is the BOLT Score and Why Does It Matter?

The BOLT score isn’t just a number—it’s a window into your body’s ability to breathe efficiently and respond to stress. It reflects the point at which you feel the urge to breathe after a normal exhalation, and it’s closely linked to:

• Respiratory health

• Carbon dioxide tolerance

• Nervous system resilience

• Oxygen delivery efficiency

Here’s why improving your BOLT score can make a real difference:

1. Respiratory Health and Oxygen Efficiency

A higher BOLT score indicates more efficient breathing and better oxygen utilisation. This means more energy, improved endurance, and a calmer physiological baseline—especially helpful for managing the pressures of daily life.

2. Carbon Dioxide Tolerance

CO₂ is often misunderstood as just a waste gas, but it’s essential for oxygen delivery. Without enough CO₂, oxygen doesn’t release easily from the blood into your tissues. A higher BOLT score reflects a healthier CO₂ tolerance, supporting energy production and overall metabolic health.

3. Stress and Anxiety Regulation

Chronic stress often leads to dysfunctional breathing: shallow, rapid, or mouth breathing. This hyperventilation lowers CO₂ levels, disrupting your nervous system’s regulation of breath and reinforcing a loop of stress reactivity.

Improving your BOLT score through breathwork helps retrain your brain’s perception of CO₂, restoring healthier patterns that support emotional balance and greater resilience under pressure.

4. Trackable Progress

Your BOLT score gives you a measurable way to track your progress. Whether your goal is to feel calmer, breathe easier, or perform better in sport or life, watching this number rise over time can be incredibly motivating.

5. Performance and Endurance

For athletes and active individuals, a higher BOLT score often correlates with improved stamina, oxygen efficiency, and reduced breathlessness during exertion. It’s a powerful tool to help you train smarter, not just harder.

How to Improve Your BOLT Score:

If your BOLT score is low (typically under 20 seconds), it’s a sign your body has adapted to over-breathing. The good news? You can retrain your system and see noticeable improvements within weeks by incorporating the following habits:

1. Breathe Through Your Nose

Nasal breathing supports better oxygen exchange and CO₂ retention. It also filters, warms, and humidifies the air—making it easier on your lungs. During exercise, try slowing down the intensity until nasal breathing feels more manageable.

2. Use Your Diaphragm

Diaphragmatic (or belly) breathing engages the full capacity of your lungs and encourages slower, deeper breaths. Place one hand on your belly and the other on your chest; aim to move the lower hand more as you inhale

3. Light, Slow Breathing

Aim for a gentle rhythm of around 5–6 seconds in and out through your nose. This helps regulate CO₂, reduces over-breathing, and brings a sense of calm. Start with 5–10 minutes, 2–3 times per day. It might feel unnatural at first, but your body will adjust.

4. Practice Breath Holds

Breath-holding after a normal exhale trains your CO₂ tolerance. Start comfortably and gradually extend the duration. Try 2–3 rounds, 2–3 times per day. You can also walk while holding your breath (one step per second), then recover with nasal breathing.

5. Exercise with Nasal Breathing

During low-to-moderate intensity workouts, maintain nasal breathing to train endurance and reduce reliance on mouth breathing. This includes daily activities like walking up stairsn or to the shops. The key here is awareness, that shift from nose to mouth breathing happens automatically. Over time, this helps normalise your breath even during physical strain.

6. Manage Stress with Breath

Mindfulness, meditation, and calming breathwork (especially light nasal breathing) support nervous system regulation. They also prevent the shallow breathing patterns that often come with chronic stress.

7. Supportive Lifestyle Habits

Good posture, quality sleep, reduced exposure to pollutants, and managing allergies or sinus issues all contribute to better breathing mechanics.

8. Consider Intermittent Hypoxic-Hyperoxic Training (IHHT)

IHHT simulates high-altitude conditions, improving your body’s oxygen efficiency and reducing the hyperventilation response. It’s an excellent option for busy people who want better and faster results without the hard work of lengthy breathwork sessions.

Final Thoughts

Your BOLT score is more than a breathing test—it’s a practical measure of your body’s adaptability, nervous system balance, and performance potential.

By improving your breathing efficiency, CO₂ tolerance, and oxygen delivery, you can unlock more energy, better focus, greater stress resilience, and enhanced physical performance.

Start small, be consistent, and give your body time to recalibrate. And if you’d like support applying these techniques or exploring advanced approaches like IHHT, get in touch—I’d be happy to help you breathe better and feel stronger from the inside out.