Breath Analysis and Peptides in Metabolic Health

Welcome to this special edition of the PNOĒ Webinar Series, where leading clinicians and health professionals explore how metabolic testing, breath analysis, and data-driven interventions are transforming the way we approach health, performance, and longevity.

In this session, we examine foundational questions with significant clinical impact. How can breath analysis reveal the true state of your metabolism? How does VO2 Max, fat oxidation, and metabolic flexibility inform personalized peptide therapy, exercise prescription, and long-term health strategies? And how can objective metabolic data guide more precise decisions in weight loss, disease prevention, and performance optimization?

If you’re looking for practical, science-led insights that can be applied immediately in clinical practice or personal health planning, this webinar brings together the most valuable findings, case studies, and frameworks shared by Dr. Leonard Pastrana and the PNOĒ team.

Unlock a deeper understanding of your metabolism with PNOĒ.
Learn how metabolic breath analysis supports evidence-based decisions in longevity, fitness, and cardio-metabolic health.

Follow PNOĒ on Instagram: @pnoe_analytics

Panos Papadiamantis:
Welcome everyone. I’m Panos Papadiamantis, Founder and Chief Product Officer at PNOĒ. Thank you for joining us today. Today, I’m very pleased to welcome Dr. Leonard Pastrana. In this webinar, we’ll be discussing fundamental concepts related to breath analysis, and more importantly, how insights from metabolic testing can be used to inform peptide therapy, as well as personalized approaches to nutrition, exercise, and lifestyle optimization.

These strategies can be applied both in the prevention of chronic disease and in the management of existing metabolic conditions. Dr. Pastrana is a long-time PNOĒ affiliate and user, with extensive experience integrating metabolic breath analysis into clinical practice alongside other biometric assessments. He is also a recognized expert in peptide therapy and joins us from New Bio Age, a leading organization in the peptide space.

Dr. Pastrana recently delivered a CME presentation at the A4M conference in West Palm Beach. Today’s session will summarize key insights from that presentation and expand on several clinically relevant case studies. Leonard, thank you for being here.

Dr. Leonard Pastrana:
Thank you, Panos. It’s a pleasure to be here and to discuss two areas that are central to my clinical work: peptides, cellular medicine, and metabolic breath analysis.

I am a pharmacist by training. As my colleagues and I began studying ways to improve cellular efficiency and optimize patient outcomes, we realized that we were addressing many of the same questions that PNOĒ focuses on, particularly through education around metabolic testing.

One important aspect of my practice is that I aim to reduce unnecessary medication use whenever possible. That approach requires reliable ways to measure whether an intervention is truly effective. We needed objective biomarkers that allow us to assess outcomes and adjust treatment plans accordingly.

We found that metabolic breath analysis is one of the most informative tools available for understanding human metabolism in real time.

Dr. Leonard Pastrana:
Today, I’ll briefly review the principles of aerobic metabolism and breath analysis, but my primary focus will be on clinical application, specifically how these tools are used in longevity medicine, weight loss, and performance optimization.

Aerobic metabolism refers to the cell’s ability to utilize oxygen to oxidize substrates, primarily fat and carbohydrates, in order to produce energy. This process is fundamental to human physiology and overall health.

In conventional medicine, we often rely on blood-based biomarkers that reflect downstream metabolic effects. What makes breath analysis unique is that it directly measures oxygen uptake, carbon dioxide production, and ventilation providing a direct view into how efficiently the body is producing energy.

Panos Papadiamantis:
To provide some context, breath analysis has been part of scientific research for nearly a century. It remains the only assessment capable of reliably evaluating how the cardiovascular, pulmonary, and metabolic systems function independently and collectively.

Although the science dates back to the early 20th century, its widespread clinical use has historically been limited by cost, complexity, and accessibility.

Dr. Leonard Pastrana:
That’s exactly right. The physiological data has always been valuable, but historically the equipment was expensive, the outputs were difficult to interpret, and analysis often required specialized expertise. As a result, this information was largely confined to research laboratories and elite performance settings.

What changed is accessibility. Platforms like PNOĒ made metabolic breath analysis portable, affordable, and clinically actionable through automated data interpretation. This shift has allowed metabolic testing to move from research environments into everyday medical and wellness practice.

Dr. Leonard Pastrana:
From a measurement standpoint, metabolic testing captures three fundamental signals: oxygen concentration, carbon dioxide concentration, and airflow volume. When these are analyzed across inhalation and exhalation, and combined with variables such as heart rate and power output, we can derive a broad range of biomarkers.

While Vo2 Max is the most widely recognized metric, it represents only a small portion of the available data.

Dr. Leonard Pastrana:
One of the most common misconceptions I see is the overemphasis on Vo2 Max as a standalone value. While it is an important indicator of cardiorespiratory fitness and longevity, it does not tell the full story.

The most clinically valuable insights often come from understanding how a person reaches their Vo2 Max, including fat oxidation, carbohydrate oxidation, metabolic flexibility, and oxygen pulse. These metrics provide deeper insight into cellular efficiency and mitochondrial function.

Estimations from wearable devices may show trends, but they lack the accuracy and depth required for meaningful clinical decision-making.

Dr. Leonard Pastrana:
This is where metabolic breath analysis becomes especially valuable in medicine. It allows us to evaluate systems not in isolation, but in relation to one another. Most chronic conditions are not the result of a single dysfunctional system; they are the product of complex interactions across metabolic, cardiovascular, and respiratory pathways.

Dr. Leonard Pastrana:
One critical metric we assess is the respiratory exchange ratio, or RER, which reflects the ratio of carbon dioxide produced to oxygen consumed. This value provides insight into which fuel source, fat or carbohydrates, the body is primarily using.

Lower RER values indicate greater fat oxidation, while higher values suggest increased reliance on carbohydrates. In metabolically healthy individuals, we expect a greater proportion of fat utilization, particularly at rest.

In metabolically inflexible individuals, we often see excessive carbohydrate reliance, even at low intensities or rest, which is associated with increased metabolic risk.

Dr. Leonard Pastrana:
When we perform exercise-based metabolic testing, we can observe how substrate utilization shifts as intensity increases. As workload rises, fat oxidation typically decreases while carbohydrate utilization increases. The point at which carbohydrates become the dominant fuel source, the crossover point, provides important insight into mitochondrial efficiency.

Because fat oxidation occurs primarily within the mitochondria, the ability to sustain fat utilization during exercise serves as an indirect but powerful marker of mitochondrial health.

Dr. Leonard Pastrana:
This becomes especially clear when comparing populations. Endurance-trained athletes are able to oxidize fat at much higher intensities. Moderately active individuals transition earlier. Individuals with metabolic syndrome may rely almost exclusively on carbohydrates from the very beginning of activity.

In some cases, fat oxidation is minimal even during low-intensity movement, which indicates significant metabolic inflexibility and impaired mitochondrial function.

Dr. Leonard Pastrana:
We observed similar patterns during the COVID period. Initially considered a respiratory illness, it became clear that many post-acute cases involved widespread mitochondrial dysfunction.

Patients with long COVID often presented with reduced fat oxidation, altered lactate responses, impaired exercise tolerance, and systemic symptoms affecting cognition, mood, and metabolism. These patterns closely resemble mitochondrial myopathies.

Panos Papadiamantis:
From a physiological standpoint, this corresponds to a leftward shift in the crossover point, indicating earlier carbohydrate dependence and reduced mitochondrial efficiency.

Dr. Leonard Pastrana:
Exactly. We documented this in several patients, including a 40-year-old male who had undergone metabolic testing prior to COVID and returned post-infection with persistent fatigue and cognitive symptoms.

His post-COVID Vo2 Max, Zone 2 range, and fat oxidation capacity had all declined significantly, clearly indicating a mitochondrial limitation.

Dr. Leonard Pastrana:
This is where metabolic testing becomes directly actionable. The assessment itself informs the treatment plan. We prescribed structured Zone 2 training, resistance training to improve glucose disposal via GLUT4, and targeted peptide strategies aimed at mitochondrial support.

By combining exercise prescription, supplementation, and peptide therapy, we were able to restore metabolic function. Within two months, his Vo2 Max, fat oxidation, and aerobic efficiency had improved substantially. Over time, he exceeded his pre-COVID baseline.

Dr. Leonard Pastrana:
These outcomes highlight why Vo2 Max is such a powerful predictor of longevity. Large-scale studies show that improvements in cardiorespiratory fitness significantly reduce mortality risk, with no apparent upper limit of benefit.

Even individuals who are already fit can meaningfully improve healthspan and lifespan by further improving Vo2 Max.

Dr. Leonard Pastrana:
This framework also applies directly to weight loss and the use of GLP-1 medications such as semaglutide and tirzepatide. While these therapies are effective for weight reduction, they can also reduce energy intake and, if mismanaged, contribute to metabolic slowdown and lean mass loss.

Using resting metabolic rate testing and metabolic breath analysis, we can identify patients at risk of weight regain and adjust treatment accordingly, often by prioritizing resistance training, protein intake, and metabolic preservation rather than continued caloric restriction.

Dr. Leonard Pastrana:
Importantly, the loss of muscle mass often associated with GLP-1 use is not caused by the medication itself, but by insufficient protein intake, inadequate hydration, and excessive caloric restriction. When these variables are managed properly, outcomes improve dramatically.

Dr. Leonard Pastrana:
The future of these therapies is already evolving. Next-generation GLP-1 compounds are being evaluated not only for weight loss, but for their ability to preserve energy expenditure, improve fat oxidation, and mimic some of the metabolic benefits of exercise.

Pharmaceutical trials now routinely measure RER, substrate utilization, and energy expenditure, the same metrics long used in metabolic testing.

Dr. Leonard Pastrana:
In summary, metabolic breath analysis provides unparalleled insight into cellular efficiency, mitochondrial health, and metabolic flexibility. It allows us to move beyond generalized recommendations and toward precise, individualized treatment strategies across longevity, performance, and metabolic health.

Watch the full episode HERE.