How a Simple Breathing Test Can Help You Gauge Your Health

Time to BOLT – Using the Body Oxygen Level Test to Measure Breathlessness

Written by
03 January 2021
Category: Performance
Views: 304

Breathless much? When it comes to physical exercise, breathing control becomes extremely important. If you find yourself running out of breath quickly during exercise, it may be because of a low tolerance to carbon dioxide (CO₂). This can happen with poor health, trauma, or dysfunctional breathing habits. To find out if this is the case, try taking your BOLT score. The Body Oxygen Level Test, or BOLT, is a simple tool to determine your relative breathing volume during rest and likelihood of breathlessness during exercise. It can be done within a minute using a simple stopwatch (in your smartphone). 

BOLT – The Body Oxygen Level Test 

Following are a simple set of steps that you can follow to determine your BOLT score: 

  • Step 1: 
    Breathe in normally through your nose and exhale normally. 
  • Step 2: 
    At the end of a normal exhale, hold your nose firmly and start the timer. Take care to keep your mouth closed and hold your nose firmly to avoid taking in more air. 
  • Step 3: 
    Time the number of seconds before your body experiences the first physical urge to take a breath. The sensations include but are not limited to a swallowing reflex, constriction of the air passage, contraction of the breathing muscles in your abdomen or throat, etc. (Note that BOLT is not a measurement of how long you can hold your breath but simply the time it takes for your body to react to a lack of air.) 
  • Step 4: 
    Release your nose and inhale through your nose. Take care to note what your first breath feels like. Your inhalation at the end of the breath hold should be calm. If your first breath is a big gasp for air, you have held your breath too long and you should repeat the test taking care to stop holding your breath at the first physical urge to breath. 
  • Step 5: 
    Resume normal breathing. 


Why is Your BOLT Score Important? 

Your BOLT score is a measure of how tolerant your body is towards carbon dioxide. The higher the level of tolerance towards carbon dioxide, the higher is the BOLT Score.  

Improving our tolerance to carbon dioxide allows us to:  

  • Be more efficient in our utilization of oxygen.  

  • Preserve the power of our breathing muscles. 

  • Maintain a buffer against elevated acid levels during exercise so that we can work out more intensely for a longer time 

  • Have smoother, more relaxed, more functional breathing even while experiencing the stress of daily life or exercise. 

What’s a Healthy BOLT Score? 

In the book, “Exercise Physiology: Nutrition, Energy, and Human Performance”, the authors William McArdle, Frank Katch, and Victor Katch state “If a person breath holds after a normal exhalation, it takes approximately 40 seconds before the urge to breathe increases enough to initiate inspiration.” The ideal BOLT score is 40 seconds. This means that an ideally healthy body should remain comfortable on one breath of air for 40 seconds before the body can no longer tolerate the increase in CO₂. . 

The ‘Inner’ Workings of the BOLT 

To truly understand how oxygen works in our body, we must grasp the role of carbon dioxide (CO₂) and appreciate its importance.  

When you hold your nose during the test, you effectively cut off additional oxygen supply from the body and make it sustain on its existing levels. As your body continues to metabolize oxygen, more and more CO₂ is created in the cells and then enters your blood. The arterial CO₂ then crosses the blood brain barrier into the cerebrospinal fluid where a few biochemical reactions involving CO₂ cause a decrease in pH level which then stimulate the central chemoreceptors in the brainstem to send signals to yet other neurons, which control the muscles of breathing, to increase ventilation by increasing respiratory rate and depth of breathing.  This is when you feel the urge to take a breath. The higher your CO₂ tolerance, the less work your breathing muscles have to do. 

It is also theorized that increasing CO₂ tolerance may increase the efficiency of oxygen delivery from the red blood cells to the tissues. CO₂ binding to hemoglobin in the RBC’s is necessary in order for oxygen to be released from hemoglobin into the blood plasma and tissues. Higher CO₂ tolerance means more oxygen is utilized from each breath that is taken. 


Better Breathing For a Better BOLT 

Even though the ideal BOLT score is 40 seconds, even seasoned athletes and fitness enthusiasts can have a low BOLT score. A common score for an individual who exercises regularly at a moderate intensity is around 20 seconds. If your BOLT score is below 20 seconds, depending on genetic predisposition, you might find that you experience a blocked nose, cough, wheeze, disrupted sleep, snoring, fatigue and excessive breathlessness during physical exercise.  

The good news is that your BOLT score can easily be increased with a series of simple breathing exercises and techniques incorporated into your daily life and exercise routine. Learning how to control breathing is a direct intervention over our physiology. The breath, mind, emotion, and beating of the heart are all connected in the nervous system. Mindful breathing techniques can decrease sensitivity to stressors that may otherwise trigger dysfunctional breathing and anxiety. Each time that your BOLT score increases by five seconds, you will feel better, with more energy and reduced breathlessness during physical exercise. 

Boost O2 programs are specially designed to help people improve their overall health and fitness using oxygen training with focused breathing protocols. One benefit that may be gained with oxygen training is an increase in BOLT score. 

Since the training happens in controlled environments and trainers, improvements in BOLT score can likely be seen within the first few weeks. 


To sum up, BOLT helps us identify dysfunctional breathing habits so that we can take steps to improve the efficiency of oxygen use in our bodies and decrease breathlessness during physical training and exercise. Breathing exercises can help improve CO₂ tolerance and decrease our body’s sensitivity to stress. 

If you’d like to experience a better life through breathing right, do not hesitate to get in touch with our teams at BoostO2. We will be happy to help you out and offer advice about the best trainings to opt for. 


For a limited time, get over 60% off your first two training sessions! The offer includes a fitness assessment, two private training sessions with an expert coach and O2 assisted breathwork.

Ready to take the next step? Then don’t delay: Talk to a Boost O2 specialist today, by phone or message—for a FREE 30-minutes, 1-on-1 consultation, on how Boost O2 can help improve your overall health, fitness and well-being.



For more information on owning your own LiveO2 system at home or partnering with Boost O2 at new location, contact to book a call, and speak direct with a Live O2 senior representative

©️2020 PT Oxygen Two Indonesia, also known as Boost O2 does not provide medical advice and the programs offered and the equipment used do not have nor require FDA approval in the USA. The equipment used is not a medical device and is not intended to diagnose, treat, cure, or prevent any disease. You may want to consult a doctor before making any change in exercise or oxygen consumption. Exercise with oxygen training has not been tested or conclusively proven to help prevent or cure any type of condition. Should you believe the information provided by Boost O2 states otherwise, please inform us directly at, so that we may amend our materials accordingly. If you have further concerns, please read and/or download the FDA’s “General Wellness: Policy for Low Risk Devices” before adopting an Exercise with Oxygen Training program.

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