Internationally renowned health and performance psychologist Dr. Leah Lagos discusses the concept of Heart Rate Variability (HRV) and how you can improve your mental and physical health by using signals from your body to gain control over stress. She’s also joined on this episode by Head Coach of the Boston Celtics, Joe Mazzulla, who has worked with Dr. Lagos on HRV training. He discusses how he uses techniques taught by Dr. Lagos to help him manage his HRV and lower stress levels during his first season as an NBA head coach in 2022.
Available now: Apple Podcasts | Spotify | Transcript
Dr. Lagos has served as a Clinical and Performance Psychologist in private practice for the past 14 years. Dr. Lagos is the author of Heart Breath Mind: Conquer Stress, Build Resilience, and Perform at Your Peak.
Mazzulla took over as the interim head coach of the Boston Celtics in September 2022 and was officially named the team’s head coach in February 2023. In his first full season on the job, he led the Celtics to the Eastern Conference semifinals and was named one of three finalists for the NBA Coach of the Year.
Here are a few highlights from our conversation:
HRV, I believe, is a biomarker that everyone should understand and know. It is a biomarker of resilience and adaptability. The larger your HRV, the more control you have over your autonomic response to stress before, during, and after a stressor.
Just understanding what the inputs are for your body is part of peak performance. If … drinking two glasses of alcohol has a really large impact on your HRV, I’m going to say maybe you shouldn’t be doing that during the week or while you’re competing or making, let’s say, trading decisions.
The heart imprints experiences, and we can train the heart to activate those experiences on demand. Then the next piece is being able to use specific experiences in specific moments of stress or to calm down or to change your physiological state.
We think of decision making as such a mental process, but your physiological state prior to making that decision and even during making that decision will impact several different pieces.
People talk about having self-compassion, but they say, “I just don’t know how to do it.” The first place I would advise is to start with training your physiology and particularly heart rate variability because you can gain control over your mind through your heart and training those heart oscillations.

