[00:00:00] Speaker A: Welcome friends, to the Heart Rate Variability Podcast. This week in Heart Rate Variability Edition, each week we explore the latest research and news from the world of hrv. Please consider the information in this podcast for informational purposes only and not as medical advice. Always consult your healthcare provider before applying any strategies we discuss.
This week we are embarking on a deep dive that truly connects the dots from the psychologist's office to the future of digital medicine. We're going to start by exploring how our heart's rhythm is emerging as a robust, objective biomarker in the treatment of depression and anxiety, and how it relates to the healing process of therapy itself.
Then we'll look at the very tools of research how scientists are creating new ways to induce and measure the precise impact of social stress on our cognitive abilities, a critical step in understanding conditions like social anxiety.
From there, we'll move to the cutting edge of digital health, breaking down a new study that uses machine learning and wearable ECGs to do something once thought impossible predict a panic attack before it happens. We'll then stay on the clinical track, looking at a brand new study from ScienceDirect that uses HRV's cousin, pulse rate variability and machine learning to create a powerful non invasive screening tool for cardiovascular risk in patients with type 2 diabetes. Next, we'll zoom out to the big picture, looking at the digital twin concept, a revolutionary idea where continuous data from our wearables, including hrv, could be used to create a digital model of our health to predict and prevent disease. We'll then bring it back to the daily grind, tackling the very real impact of work stress on our heart health and how HRV is the single best metric to track our resilience. Finally, we'll end with a simple and powerful tool that you can use right now to take control of your nervous system, resonance breathing. It's a packed show, so let's get started.
Our first story comes from the world of psychotherapy and tackles a question fundamental to the healing process.
Can we see recovery on a physiological level? We know that affective disorders like major depression and anxiety aren't just in the mind. They are whole body conditions. They disrupt sleep, drain energy and fundamentally alter our physiology. A hallmark of this disruption is a suppressed or blunted heart rate variability, indicating a nervous system stuck in a rigid, sympathetic state.
A fascinating new paper published on October 10, 2025 in the journal BMC Psychology explores this connection directly. The paper is titled the Relationship between Heart Rate Variability and Affective Associations with Symptomatic Improvement and Therapeutic Alliance.
The authors are Alexandra F. Gonsalves, Eugenia Ribeiro, Adriana Sampaio, Natividade S. Cotopera, Pedro Moreira and Joanna F. Coutinho. This research team set out to answer three core questions. First, could they confirm this well known finding that individuals with affective disorders have lower HRV than healthy controls? Second, and more importantly, would a patient's HRV change as they went through therapy? And specifically, would an increase in hrv, a sign of growing autonomic flexibility, correlate with a decrease in their symptoms? Third, they wanted to explore a beautiful concept rooted in polyvagal theory, the link between HRV and the therapeutic alliance. The therapeutic alliance is that vital, intangible bond of trust, collaboration and safety between a patient and their therapist. The theory suggests that a more regulated nervous system might make it easier for a patient to engage in the social connection system, thereby building a stronger alliance. To test this, the researchers recruited 42 participants, 21 individuals diagnosed with depression or anxiety who were beginning psychotherapy and 21 healthy controls. They measured HRV at a baseline and for the patient group they continued to measure it throughout all of their therapy sessions. To track progress, they used two key questionnaires, the Outcome Questionnaire, which measures a patient's symptoms and distress, and the Working Alliance Inventory which measures the strength of that patient therapist bond. The results were incredibly insightful. First, they confirmed their initial hypothesis. The patient group had significantly lower HRV at baseline compared to the healthy controls, confirming this physiological signature of affective disorders. Second, in a profound finding, they discovered that as patients progressed through therapy and their symptoms of depression and anxiety decreased, their heart rate variability increased. This provides tangible, objective evidence that psychotherapy is not just talking about your problems. It is a deep intervention that can, over time remain restore flexibility to the autonomic nervous system. As the mind heals, the body's fundamental rhythms heal with it. However, the third hypothesis was not confirmed in this study. The researchers did not find a significant link between a patient's HRV and the strength of the therapeutic alliance. This is just as important as a positive finding as it tells researchers that this connection is not as simple as higher hrv, better alliance and and that more work is needed to understand how that relational magic truly gets under the skin.
For anyone who has ever been in therapy, this study validates the experience.
It shows that the hard work of healing can be seen and measured in the restored flexible rhythm of your heart.
From the therapy room, we move into the research lab. Our first story showed that a low rigid HRV is linked to anxiety, but how does this anxiety, particularly social anxiety, actually affect our brains in real time? To study this, researchers need tools that can reliably and safely induce a specific type of stress while simultaneously measuring its effects. This is precisely what a team in Germany accomplished in a new study published in Scientific Reports.
The paper is titled Development and Validation of the Socio Evaluative in Back Task two to investigate the impact of acute social stress on working memory. The authors are Matthias Hauka, Sabrina Golda and Stefan Heinzel. Let's break down what they built because it's pretty clever. The N back task is a classic and notoriously difficult cognitive test. It's a pure test of working memory. What Hauk and his team did was add a potent layer of social stress. They created the socio evaluative in back task or or sent.
In this version, participants perform the difficult end back task while being told they are being watched, filmed and judged by a live panel of evaluators. This socio evaluative threat is one of the most potent stressors we can experience.
The goal was to see if this newcent tool could induce a stress reaction and measure how that stress impairs explicit working memory. They recruited 57 individuals stratified into those with high social anxiety and HSA and those with low social anxiety.
The results were fascinating. First, the tool worked. The sense successfully increased psychophysiological stress reactions and reduced working memory performance overall. But the real nuance was in the difference between the groups. The individuals with low social anxiety LSA actually showed faster reaction times under stress, as if it focused them.
In contrast, the individuals with high social anxiety HSA showed consistent reaction times regardless of stress. The authors suggest this might reflect a kind of cognitive avoidance. The HSA individuals may be so consumed by the distressing thoughts about being evaluated that their attentional resources are already maxed out. This study is so important because it gives researchers a validated tool.
Now other scientists can use the scent and combine it with HRV measurements or brain imaging to see exactly what happens in the brain and body when social evaluation causes our working memory to falter. We've talked about chronic affective disorders and the acute stress of social evaluation.
Now we're going to the extreme end of the anxiety spectrum. The panic attack.
For anyone who has experienced one, it is a terrifying physiological and psychological storm.
A core feature of panic disorder is the fear of the fear itself. The constant dread filled anticipation of the next attack.
[00:08:52] Speaker B: This dread is what makes our next study so revolutionary. What if a wearable on your wrist could give you an early warning? What if it could tell you your physiology is moving into a pre panic state. You have time. You can use your tools before the attack even hits.
[00:09:10] Speaker A: This is the goal of a milestone study published on October 15, 2025 in the journal of Medical Internet Research.
The paper is titled Panic Attack Prediction for Patients with Panic Disorder via Machine Learning and Wearable Electrocardiography Monitoring Model Development and Validation Study. The long list of authors includes Hyung oh, Hunmin Do, Chae Hyun, Maeung Jinsuk, Park Tae Joon, Yoon Ji Hwan, Kim Hyerin, Hwang SEO and Choi, and Piao Huilin. This team set out to build a multimodal deep learning framework. Multimodal is the keyword. They are combining two powerful inputs, real time physiological signals from a wearable electrocardiogram, ECG monitor and baseline psychological assessments. Here's how they did it. They adapted a deep learning architecture called ConvNetquake, initially designed for seismic detection to listen for personal quakes, the subtle patterns in HRV that predict the onset of a panic attack. The AI wasn't just learning what does a pre panic heartbeat look like? It was learning what does a pre panic heartbeat look like in a person with this specific psychological profile in history.
The results are astounding for this field. The final model achieved an accuracy of 71.43%, but even more impressive, the precision was 83.72%.
This is critical. It means that when the model sounded the alarm, it was correct almost 84% of the time, preventing alarm fatigue. The recall was 70.59%, meaning it successfully caught over 70% of the actual panic attacks. The researchers were clear that this multimodal approach was significantly more reliable than than using either data source alone. This study provides the first significant empirical support for a wearable based just in time early warning system for panic attacks. This is the future of digital psychiatry, moving from reacting to mental health crises to anticipating them. Let's stay in this world of clinical diagnostics. We've just seen how machine learning can interpret HRV to predict a mental health crisis. Our subsequent study uses a very similar approach to screen for a physical health risk.
We're moving into the realm of chronic illness, specifically type 2 diabetes. A new study published on the ScienceDirect platform in the journal Biomedical Signal Processing and Control.
The paper is titled Non Invasive Cardiovascular Risk stratification in type 2 diabetes A pulse, Wave and Pulse Rate Variability Analysis with Machine Learning.
This work was authored by Sourav Kumar Apocrita Tayati, Amber Srivastava and Ravi Bahalamudi. This study uses a very close cousin of HRV pulse rate variability or prv. This is what's measured by the light based sensor on a smartwatch, HRV tracker or a fingertip pulse oximeter. The researchers didn't just look at prv, they also analyze the pulse wave itself, the shape of the pulse, which can reveal information about arterial stiffness. They hypothesize that feeding these two non invasive signals, PRV and pulse wave shape, to a machine learning model would accurately screen for cardiovascular risk. The study aimed to examine these alterations in diabetic patients compared to healthy participants to evaluate this method's diagnostic potential for non invasive pore screening.
The results were extremely promising. The machine learning models were able to stratify the patients with a high degree of accuracy. This means the pulse data was capturing a real time functional snapshot of cardiovascular health that a static cholesterol number might miss. Think of the implications.
Instead of relying only on blood work, a patient could sit for a simple 5 minute pulse wave reading in AI would analyze the data and and the doctor would get a report.
This patient's pulse wave dynamics suggest a high degree of arterial stiffness and autonomic dysregulation, placing them in a high risk category. It's another perfect example of how machine learning is unlocking the deep information hidden in our body's simple rhythms.
[00:13:37] Speaker B: This week in HRV is brought to you by Optimal hrv. We spend so much time on this show talking about the why of hrv.
[00:13:44] Speaker A: But Optimal HRV is all about the.
[00:13:47] Speaker B: How and it's about making your HRV data accessible and understandable from the moment you start.
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[email protected] welcome back. Let's take a look at HRV in the news this week.
Starting WTA Time Magazine article We've just been discussing the incredible focused power of using wearables to predict a single event like a panic attack or to screen for diabetes risk. Now I want to zoom all the way out what happens when you don't just track one thing, but, well, everything. What if you could combine your daily hrv, your sleep data, your blood glucose, your environmental exposures, and even your annual MRIs into one massive living model of you?
[00:15:12] Speaker A: This is the concept of the digital twin. And it's the subject of a brilliant interview published in Time magazine. The article is titled How Tracking youg Health Metrics Can Help youp Live Longer. Written by senior correspondent Alice Park. The interview is with Zahi Fayed, a professor of radiology and director of the Biomedical Engineering and Imaging Institute at Mount Sinai.
Fayed is leading a revolutionary study to see if we can use the explosion of wearable technology to do more than just count steps. He makes a powerful point. Your annual doctor's visit is just a single snapshot. You're missing what happens the other 364 days of the year. You need continuous data to build a true digital twin. So his team is equipping participants with what he calls a swag bag of health devices.
This includes an Oura ring for 247 tracking of sleep activity and heart rate variability. It consists of a blood pressure cuff, a smart scale and a continuous glucose monitor.
But it goes deeper, including a home spirometer for lung function and even a silicon band to measure environmental exposure to chemicals. Finally, participants get quarterly at home blood analyses and a full body multi organ MRI once a year. When you put all this together, you get a high resolution, evolving digital model of one person.
So what do you do with it? Fayyad, an engineer, says the goal is to find the small dip, the pre symptomatic change, like a slight drop in HRV combined with a new pattern in glucose that signals disease years before you feel a single symptom.
Once the digital twin sees that dip, it becomes a simulation engine. Fayat's team can run billions of what if scenarios to find the smallest intervention, like shifting a sleep time by 30 minutes. That will have the most significant impact on correcting that trajectory.
His goal, he says, is not just lifespan, but health span. And in this vision, HRV is the continuous high frequency data stream that that knits the entire digital twin together. That vision of the future is inspiring, but let's bring it back to right now, to the reality most of us live in. We may not have a digital twin, but we do have a level of chronic work stress that is frankly, terrifying.
An article published in Boxlife magazine and featured in Men's Health puts this into stark perspective. Written by Julianne Raby, the headline says it all stressed at work. Your heart disease risk just jumped 50%.
Here's the one number that shows how to fight back.
That one number, as you've guessed, is heart rate variability. This article is a fantastic practical guide to why HRV is the single most important metric for managing the physiological damage of our modern lives. It starts by reminding us that chronic stress isn't just a feeling, it's a constant cascade of cortisol and adrenaline. It cites a 2022 article from the Journal of Clinical Medicine to back up that staggering 50% increased risk of heart disease from job related stress. This is where HRV becomes your diagnostic tool. It is the Stress Resilience score hiding in your chest. The article quotes Dr. Tamanasing, director of the Cleveland Clinic's Sports Cardiology center, who gives one of the best definitions I've heard. In general, the higher your hrv, the more resilient your heart. A high HRV means your parasympathetic system is strong and can pull you back from a stressful email. A low HRV means your sympathetic system is dominant.
So how do you fix it? The article stresses consistency. It lays out four of the most effective real world habits.
Train consistently, but don't overdo it. Exercise boosts hrv, but overtraining crushes it. Cut the alcohol. Eat for recovery. Even moderate alcohol can tank your hrv. Breathe like it's a workout. The article specifically calls out resonance breathing, calling it resistance training for your vagus nerve.
Harness the power of sleep wake consistency the article quotes Kristen Holmes of whoop, who says that going to bed and waking up at the same time every day, including weekends, is a massive driver of parasympathetic activity. The goal is not to chase some arbitrary HRV benchmark, but to watch your own trends over time and stay on the high end of your personal range. We just heard the BoxLife article call breathing a workout for your vagus nerve.
Our final piece today from Bustle gives us the exact exercise plan. It's an article by Carolyn Steber titled Resonance breathing is the anti stress hack you can do anywhere.
This piece demystifies a practice that has been gaining tremendous traction. When we're stressed, our breathing becomes quick and shallow. We get lightheaded and we get more stressed. Resonance breathing is the circuit breaker. It is simply the act of breathing in and out at the same slow frequency. The most common rhythm is an inhale for five seconds followed by an exhale for five seconds. This results in six breaths per minute. The article quotes Chloe Bean, a somatic trauma therapist who explains the mechanism perfectly when you breathe at this slow, even pace, it sinks your heart and blood pressure and maximizes heart rate variability. HRV activating the body's calming system this specific rhythm, around six breaths per minute, is called the resonance frequency because it's believed to be the natural resonant frequency of our cardiovascular system.
While six breaths a minute is a good starting point, taking a resonance frequency assessment such as the one included in the optimal HRV can help you find your own unique breathing rate to maximize the impact of our breath work. When you breathe at this pace, your heart rate, your blood pressure and your breath all begin to oscillate and in a single, smooth, coherent wave, this coherence directly stimulates the vagus nerve, which is the superhighway of your parasympathetic system. The best part, as the title says, is that you can do this anywhere. We have covered a tremendous amount of ground today, from the therapy room to the digital twin, from chronic disease to a simple breath. What does this all mean for us? Let's distill it into our actionable insights. First, for individuals, the message this week is one of empowerment. Your HRV is a real, tangible signal of your mental and physical well being. The BoxLife article gives you the long term prioritize sleep consistency above all else, train smart and be mindful of alcohol. The Bustle article gives you the short term resonance breathing Set a timer for five minutes a day and practice it.
And if you struggle with anxiety OR diabetes, the JMIR, BMC and ScienceDirect studies are a beacon of hope, showing that new tools are being built to help you heal, screen for risk and even predict your needs.
Second, for clinicians, the study in BMC Psychology is a call to action. HRV is not just a wellness metric, it's a robust, non invasive biomarker for tracking progress in affective disorders.
For those treating panic disorder, the JMIR study is a preview of the just in time digital interventions that are on the horizon. And for GPs treating patients with type 2 diabetes, the Biomedical Signal Processing Study on ScienceDirect shows that AI powered PRV analysis could soon be a powerful low cost screening tool for cardiovascular risk. Third, for researchers, the field is exploding.
The Scientific Reports article by Hake et al. Gives you a new validated tool, the sint, to finally start teasing apart the precise mechanisms of social stress and working memory. The BMC study's null finding regarding the therapeutic alliance presents a new puzzle and for the engineers, the JMIR and Science Direct studies are powerful proofs of concept. The next step is to refine these models, test them in large, diverse clinical trials, and improve their predictive power.
Finally, for businesses and leaders, the BoxLife article should be mandatory reading. A 50% increase in heart disease risk from work stress is not a soft HR problem. It's a critical bottom line risk. A workforce with low HRV is a burnout rigid and unhealthy workforce. You can fight this by promoting a culture that actually values recovery. This means encouraging off time, modeling healthy boundaries and championing policies that support sleep consistency.
Not a 247 on culture. The future, as the Time article shows, is in preventative, continuous health.
Your organization's health span depends on it and that is our week. From the inner world of our emotions to the complex data of our digital selves. And HRV remains the common thread, the rhythm that tells the story of our health.
Thank you for joining us on the Heart Rate Variability podcast.