When we think about the factors limiting human endurance, our minds often turn to the heart’s ability to pump oxygen-rich blood or the muscles’ capacity to utilize that oxygen. But what if the lungs played a bigger role than we previously thought? Olivia Ferguson, a researcher at the University of British Columbia (UBC), is at the forefront of this evolving conversation. Her recent study, featured in Outside magazine, is shedding new light on the phenomenon of air hunger and its impact on high-performance athletes.
The Air Hunger Puzzle
Ferguson, working alongside her mentor Jordan Guenette, took a deep dive into the nuances of breathlessness during intense exercise. Traditionally, respiratory limitations have been overlooked in healthy individuals. However, their research, published in Medicine & Science in Sports & Exercise, challenges this assumption.
By analyzing lung-function test data from 321 adults, Ferguson and her team discovered that a significant portion of fit individuals experience a specific type of breathlessness known as air hunger. This sensation—characterized by the feeling of being unable to take a full breath—was commonly believed to affect only those with respiratory diseases. Yet, their study revealed that 34% of healthy individuals also experience it, with fitter athletes being more susceptible.
Why Does This Matter?
The implications of Ferguson’s findings extend far beyond the lab. Her research suggests that air hunger isn’t just a discomfort—it actively influences an athlete’s decision to stop during an exhaustive effort. Participants who reported air hunger also noted higher breathing discomfort and were more likely to cite it as a factor in their exercise cessation.
A key physiological mechanism behind this is critical inspiratory constraints (CIC). When we reach a point where deeper breathing becomes physically difficult, the brain perceives a mismatch between the need for oxygen and the ability to inhale sufficiently. This can create a powerful emotional response, potentially impacting athletic performance.
The Role of Isocapnic Training
One of the most exciting aspects of Ferguson’s research is its potential to reshape how we train for endurance. If breathing discomfort is limiting performance, can respiratory training mitigate its effects? The Isocapnic Breathe Way Better (BWB) device, which ensures CO2 levels remain stable during respiratory training, might hold the key.
Ferguson has begun exploring the potential benefits of Isocapnic training for athletes who struggle with air hunger. Unlike traditional breath training, which can lead to hyperventilation and CO2 loss, Isocapnic training strengthens respiratory muscles while preserving optimal gas exchange. This could help athletes extend their inspiratory capacity, reduce the perception of breathlessness, and improve overall endurance. We will have more to share about this ground breaking research when it is complete.
Air Hunger and Endurance Performance
What’s Next?
Ferguson’s work has already sparked interest in the endurance sports community. With further research, we may soon see targeted respiratory training protocols for athletes looking to push past their perceived breathing limits. Her findings challenge the long-held belief that the lungs are never the limiting factor, opening new possibilities for improving human performance.
As the field of sports science continues to evolve, Ferguson’s research reminds us that the key to unlocking endurance potential might be right under our noses—literally. If air hunger is a barrier to peak performance, it’s time to rethink how we train the breath, and Isocapnic training could be the next breakthrough in endurance optimization.
Check out Olivia’s research here.
Read Alex Hutchenson’s article for Outside magazine here.
Or
This article about HIIT how Isocapnic training improves HIIT
AUTHORSHIP AND TRANSPARENCY
About this article
Written by
Coach Luke Way is the founder and CEO of Isocapnic and has coached endurance athletes for 20 years. He specializes in elite triathlon, mountain biking, CrossFit, and physiology-led athlete assessment.
Scientifically reviewed by
Dr. Andrew Sellars is a Canadian physician, anesthesiologist, performance physiologist, entrepreneur, and coach with a Master's degree in Athletic Coaching. He co-founded VO2 Master and is Co-Founder, Chief Science Officer, and Physiology Advisor at Isocapnic Technologies Inc., where his work focuses on biomarker-guided training and respiratory performance.
Review completed: August 1, 2026
