April 22, 2021

Breath analysis - The most complete picture of your body

In this blog, we discuss what breath analysis is, what it is measuring and how broad is its scope of applications. Learn the story behind one of the most revolutionary methods of analysis that can transform your health and wellness.

What is Breath Analysis and what does it measure? 

Breath analysis (AKA cardio-metabolic testing, VO2max testing, ergospirometry, cardiopulmonary exercise testing, or metabolic testing) is the method of analyzing several elements of your exhaled and inhaled breath. It was initially conceived in the 1920s and since then has gradually evolved to become a key biometric assessment in several disciplines of medicine and sport science. 

During a breath analysis test, three main elements of the human breath are analyzed on every breath cycle: The volume of air exchanged with the environment, the concentration of oxygen (O2), and the concentration of carbon dioxide (CO2). The value of each metric is measured several times per second capturing its evolution through inhalation and exhalation.  

Figure 1

Figure 1 shows 5 consecutive breath cycles. During exhalation, the concentration of O2 drops while the concentration of CO2 rises as air from deeper within the lungs. That’s because air has remained in the lungs for a longer period of time resulting in more absorption of O2 and extraction of CO2 from the blood. In the third graph, you can see the rate of air volume rising at the beginning of exhalation reaching its peak and then going back to 0 before reversing due to the transition between exhalation and inhalation.

By combining the three fundamental metrics (i.e. O2, CO2, Flow) one is able to calculate the 11 basic breath analysis variables:

  1. BF - The number of breaths you take every minute

  2. VT - Volume of air exchanged between your lungs and environment every breathing cycle

  3. FeO2 - The fraction of oxygen you absorb for the air you inhale

  4. FeCO2 - The fraction of carbon dioxide in the air you exhale

  5. HR - Your heart rate

  6. VE - The volume of air exchanged between your lungs and environment every minute

  7. VCO2 - The volume of carbon dioxide produced by your body every breathing cycle

  8. VO2 - The volume of oxygen consumed by your body every breathing cycle

  9. Fat/Carb - The contribution of fats and carbohydrates in the calories you burn

  10. Kcal -The calories you burn

  11. O2pulse - The amount of oxygen your heart pumps into your body per heartbeat

How does breath analysis scan your heart, lungs, circulation, and cells?

Keeping your vitals going (e.g. heart, brain liver function) and performing physical work (e.g. running, going up the stairs, etc.) all depend on one basic function. Using oxygen to burn macronutrients (e.g. fats and carbs which are your body’s main fuel source) in your cells and releasing their energy in order to cover the energy demands of your organs and body movement. The process of burning fats and carbs also produces CO2 which is cleared from the bloodstream and expelled through exhalation. This process is what we generally refer to as Metabolism and the schematic below provides its overview: 

The four main systems required for your metabolism to work are your heart, lungs, bloodstream, and cells. The primary task for these systems is to transport oxygen to the cells and clear carbon dioxide. Any disruption of this process will immediately impact your ability to move or even stay alive. Breath analysis provides us with 12 biomarkers which when analyzed in specific combinations allow us to zoom in on each system and analyze how effectively each one is working.   

Figure 2

Figure 2 shows how the 3 fundamental metrics (i.e. O2, CO2, flow) are combined to generate the 12 basic variables of breath analysis which are then combined under specific combinations to evaluate how specific elements of your body are working.

Applications of breath analysis

Thanks to its ability to analyze how your cells, heart, lungs, and bloodstream are working individually but also in unison, breath analysis has been used in several disciplines of the wellness and medical industry including cardiology, pulmonology, endocrinology, sport science, and weight loss. 


  • Analyzing risk improvement or deterioration in heart failure patients by measuring peak oxygen consumption [1].

  • Detecting the presence of ischemic heart disease by analyzing the amount of oxygen the heart pumps in every heartbeat [2]. 

  • Triaging between pulmonary and cardiovascular disease in patients presenting with chest pain and dyspnea [3]


  • Detecting lung limitations attributable to mobility problems such as lung muscle atrophy, ribcage mobility limitation, etc [4]. 

  • Detecting lung limitations attributable to conditions damaging the lung itself (e.g. COPD, pulmonary embolism) [5].

  • Detecting cases of chronic hyperventilation [6].


  • Detecting predisposition for metabolic syndrome by analyzing the ability to switch between fuel sources (i.e. fats and carbohydrates) at rest and during exercise. [7], [8]

  • Measurement of caloric needs and development of personalized nutrition program (see Weight loss below) [9], [10].

Sport Science [11]:

  • Identification of system(s) (i.e. lungs, heart, cells, circulation) limiting the ability to workout

  • Identification of personalized heart rate training zones, ventilatory and anaerobic threshold

  • Identification of breathing training zones

  • Identification of optimal distribution between low-intensity cardio, interval training, and resistance training depending on limitation and fitness goal

  • Determination of fueling requirements during physical activity by measuring fat and carbohydrate burn during different levels of exercise intensity

Weight loss:

  • Identification of reduced caloric expenditure at rest and during movement (i.e. metabolic slowdown) [12].

  • Determination of optimal caloric intake target based on intended weight loss [9].[10]

  • Risk assessment for likelihood of weight gain or weight regain [13]


  1. CPET in heart failure European Heart Journal Supplements, Volume 6, Issue suppl_D, August 2004, Pages D1–D4, https://doi.org/10.1016/j.ehjsup.2004.05.018

  2. Cardiopulmonary exercise testing is more accurate than ECG-stress testing in diagnosing myocardial ischemia in subjects with chest pain https://doi.org/10.1016/j.ijcard.2014.04.102

  3. ATS/ACCP Statement on Cardiopulmonary Exercise Testing Am J Respir Crit Care Med Vol 167. pp 211–277, 2003 DOI: 10.1164/rccm.167.2.211

  4. Smith MD, Russell A, and Hodges PW (2006): Disorders of breathing and continence have a stronger association with back pain than obesity and physical activity. Australian Journal of Physiotherapy 52: 11-16

  5. Ventilatory Inefficiency and Exertional Dyspnea in Early Chronic Obstructive Pulmonary Disease, DOI: 10.1513/AnnalsATS.201612-1033FR

  6. Brat K, Stastna N, Merta Z, Olson LJ, Johnson BD, Cundrle I Jr. Cardiopulmonary exercise testing for identification of patients with hyperventilation syndrome. PLoS One. 2019 Apr 23;14(4):e0215997. doi: 10.1371/journal.pone.0215997. PMID: 31013331; PMCID: PMC6478351.

  7. Lipid Oxidation Assessed by Indirect Calorimetry Predicts Metabolic Syndrome and Type 2 Diabetes., Pujia A, Mazza E, Ferro Y, Gazzaruso C, Coppola A, Doldo P, Grembiale RD, Pujia R, Romeo S and Montalcini T (2019) Lipid Oxidation Assessed by Indirect Calorimetry Predicts Metabolic Syndrome and Type 2 Diabetes. Front. Endocrinol. 9:806. doi: 10.3389/fendo.2018.00806

  8. Metabolic Flexibility as an Adaptation to Energy Resources and Requirements in Health and Disease., doi: 10.1210/er.2017-00211

  9. Employing RMR Technology in a 90-Day Weight Control Program Obesity Facts 2008;1:298–304 Published online: December 2, 2008 DOI: 10.1159/000178026

  10. Global Journal of Obesity, Diabetes and Metabolic Syndrome Stump C, Jackemeyer D, Abidov Y, Herbst K, Tao N, et al. (2017) Study of the Effect of Mobile Indirect Calorimeter on Weight Management. Glob J Obes Diabetes Metab Syndr 4(2): 044-050. DOI: http://doi.org/10.17352/2455-8583.000022

  11. Cardiopulmonary exercise testing, Relevant but underutilized., Postgraduate Medicine, Volume 122, Issue 6, November 2010, ISSN – 0032-5481, e-ISSN – 1941-9260

  12. Adaptive thermogenesis in humans., Int J Obes (Lond). 2010 October; 34(0 1): S47–S55. doi:10.1038/ijo.2010.184.

  13. Marra M, Scalfi L, Covino A, Esposito-Del Puente A, Contaldo F. Fasting respiratory quotient as a predictor of weight changes in non-obese women. Int J Obes Relat Metab Disord. 1998 Jun;22(6):601-3. doi: 10.1038/sj.ijo.0800612. PMID: 9665683.

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