What is the BOLT Score and How to Improve it

Jun 28, 2023

When it comes to improving wellbeing and bodily performance, the BOLT score (Body Oxygen Level Test) stands out as a valuable metric. It offers insights into our respiratory health, carbon dioxide tolerance, nervous system resilience and oxygen delivery capacity. In this blog post, I explore its significance of the BOLT score, why it matters, and how you can improve it.

If you haven’t done so already then you can learn the simple steps to finding out your BOLT score and what the results mean here.

Why is your BOLT score Important?

The BOLT score is not just a number; it is a window into your breathing efficiency and overall respiratory function as well as your body’s adaptive capacity. It also indirectly provides insights into the regulation of the nervous system. The nervous system, specifically the autonomic nervous system, plays a crucial role in regulating our physiological processes, including breathing.

Here’s why it’s important to know and improve your BOLT score:

1. Respiratory Health: The BOLT score serves as an indicator of your respiratory health and lung capacity. A higher BOLT score suggests efficient breathing and better oxygen utilisation, which can positively impact your overall wellbeing and ability to manage stress.

2. Carbon Dioxide Tolerance: Carbon dioxide (CO2) is not just a waste gas that we exhale, it holds the key for unlocking oxygen delivery to our cells. Our cells need oxygen to produce energy in the form of ATP. This energy is vital for all the processes that keep our body alive and functioning properly. A higher BOLT score reflects an improved tolerance to CO2, allowing your body to efficiently utilise oxygen and deliver it to tissues and organs.

3. Stress and Anxiety Management: Chronic stress and anxiety often lead to over breathing, this can show up as loud breathing, mouth breathing or shallow, rapid breathing. This is the hyperventilation response and it means that you take in too much oxygen and create an intolerance for CO2. This increase in O2 intake and intolerance for CO2 will change the way your brain monitors respiratory gases because it has now ‘got used to’ over breathing and decided this is what you need. Your brain will now be driving your dysfunctional breathing pattern, compromising your ability to negotiate stressors at a physiological and psychological level.

Monitoring your BOLT score can help you identify breathing pattern irregularities and know when to take steps to recover optimised breathing. Slow, controlled breathing techniques employed to improve the BOLT score will help change the biochemistry driving this process and help you feel calmer and more capable in managing stress and emotional reactivity.

4. Progress Tracking: The BOLT score provides a tangible measure of improvement over time. As you practice breathing techniques and exercises, tracking your BOLT score allows you to see the progress you are making, providing motivation to continue your journey towards optimal breathing and health.

5. Performance Enhancement: For athletes and active individuals, a higher BOLT score can contribute to improved endurance and enhanced athletic performance. By increasing your BOLT score, you optimise oxygen uptake and utilisation, potentially unlocking new levels of physical achievement.

How to Improve Your BOLT Score:

Now that you understand the importance of the BOLT score, let’s explore some effective strategies to improve it:

1. Nasal Breathing: Breathe through your nose as much as possible. Nasal breathing filters, warms, and humidifies incoming air, promoting optimal oxygen uptake and facilitating better CO2 regulation. When doing exercise try breathing through your nose. If you have a low BOLT score then you could try slowing down your exercise intensity until you can breathe through your nose for longer.

2. Diaphragmatic Breathing: Practice diaphragmatic breathing, which involves using the diaphragm to engage in deep, efficient breaths. This technique maximises oxygen intake and improves lung capacity.

3. Reduce Breathing Volume: Focus on breathing lighter and slower, ideally with a pace of 5-6 seconds on the inhale and the same length on the exhale. This will meet your body’s oxygen needs while maintaining a relaxed, optimised breath. Reducing breathing volume enhances CO2 tolerance and minimises the risk of over-breathing. If this feels difficult then pace yourself as your body will adjust over time. If you have a low BOLT score know that you have become used to over breathing and your body may resist the lower air intake initially. Try 5-10 minutes three time per day for a week and you will notice it becoming easier.

4. Increase Breath-Holding Time: Regularly practice breath holds to gradually increase your BOLT score. Start by comfortably holding your breath after a normal exhalation and gradually extend the duration over time. Doing this 2-3 times per day over a period of a few weeks will quickly increase your BOLT score. This exercise improves CO2 tolerance and facilitates enhanced oxygen delivery to cells. For some people walking while breath holding can be a welcome distraction. At the end of the exhalation pinch your nose and take one step per second until you need to take the next inhalation. Stop, recover normal breathing and comfort and then try again.

5. Physical Exercise with Nasal Breathing: Incorporate physical exercise into your routine while maintaining nasal breathing. Begin with low-intensity activities and gradually increase the intensity. Nasal breathing during exercise optimizes oxygen uptake, improves endurance, and reduces the likelihood of hyperventilation.

6. Stress Management: Employ stress reduction techniques such as mindfulness, meditation, or relaxation exercises. By by incorporating nasal breathing and practising light breathing (reducing the volume of oxygen taken in) you can prevent shallow breathing and maintain healthy respiratory patterns alongside calming your nervous system.

7. Lifestyle Adjustments: Adopt lifestyle habits that support healthy breathing. Maintain good posture to allow for optimal lung expansion, ensure a conducive sleep environment and pre sleep routine, manage allergies or sinus issues, and minimise exposure to environmental pollutants.

8. Intermittent Hypoxic/ Hyperoxic training: This in an innovative approach to oxygen therapy which trains the body to adjust to high altitude conditions. When we spend time at high altitude the body has to adjust and become more oxygen efficient this is why this approach is also known as Altitude Training. By helping your body to get used to operating efficiently with less oxygen it helps reduce the hyperventilation response and increase tolerance for Co2. If you are a busy person who cannot commit the time to dedicated breathing practices then this is the quickest route to helping you body adjust for greater efficiency and performance.


Your BOLT score is a powerful tool for optimising your breathing and overall wellbeing. By understanding its significance and implementing techniques to improve it, you can enhance your respiratory function, carbon dioxide tolerance, and oxygen delivery capacity. These three factors have the power to help improve your physical performance, stress management, as well as your vitalty. 

Remember, consistency and patience are key. Consult with a qualified instructor or healthcare professional to personalise your approach and ensure that you are practicing breathing techniques safely and effectively.