Current approaches to resilience development in high-performance environments tend to focus on two things well: stress tolerance, the ability to keep functioning under discomfort, and cognitive framing, mindset and psychological interpretation of pressure.
Both are valuable. Both are quite well established across military, aviation, sport and performance psychology.
What is less well trained are the other components that sit alongside them: recovery capacity, autonomic regulation, and the capacity to respond rather than react under pressure. Together these form a more complete picture of what sustainable resilience actually requires.
Of these, autonomic regulation, the nervous system’s actual capacity to regulate, recover from, and adapt to stress, is where HRV comes in.
Growing literature suggests HRV, particularly RMSSD, offers meaningful insight into workload tolerance, recovery capacity and performance under strain. Studies in aviation and performance contexts have shown associations between HRV and successful task completion, cognitive performance under load, and training adaptability.
But here is something emerging from Trial 1 of the HPBUT programme that I find genuinely interesting.
HRV alone does not tell the whole story.
Some participants show relatively stable HRV while reporting fluctuating subjective stress. Others report stable subjective experience despite lower HRV readings. Physiological regulation, subjective stress experience and behavioural performance do not always move in parallel.
This suggests resilience cannot be meaningfully reduced to a single universal HRV threshold. It is better understood as an interaction between:
— Recovery capacity
— Physiological tolerance
— Autonomic regulation
— Adaptive stress framing
— Behavioural adaptation under strain
What I find particularly interesting is that breath sits at the centre of all five.
Recovery — Targeted breath techniques actively accelerate return to baseline after a stressor, rather than waiting for passive recovery.
CO₂ tolerance — Extended exhale work and hypoxic training directly build physiological tolerance to discomfort, expanding the window within which a person can remain functional under rising internal pressure.
HRV — Slow, structured breath training is one of the most consistently supported methods for improving autonomic regulation and HRV over time. This is not incidental, it is the mechanism.
Cognition — Clear thinking under pressure is heavily dependent on nervous system state. A dysregulated system narrows attention, impairs working memory and reduces decision quality. Breath is the most direct voluntary handle on that state.
Threat response — Survival reactions emerge from physiological state, not conscious choice. But breath awareness creates the conditions for a tactical pause, enough space to interrupt automatic escalation, regulate, and choose a response rather than simply react.
This is what HPBUT Trial 1 through Trial 3 is designed to train and assess, not as a standalone wellness intervention, but as a structured component of performance development embedded within high-demand training pipelines.
The question is not whether people can tolerate stress. Most high performers already can.
The question is whether we can train the full system, so that tolerance, regulation and interpretation work together, protecting both immediate performance and long-term sustainability.
That is what the research succession is designed to find out.
If this resonates, I’d love to hear from you. DM me if you’d like to attend an upcoming workshop, join the waiting list for the next HPBUT cohort, or find out about the 31 day course, a self-led introduction to breath regulation you can start today.