Now we delve into the fascinating topic of how HRV and the autonomic nervous system relate to each other. We’ve learned that the brain reacts to stressors by activating the amygdala, which in turn triggers the sympathetic component of the autonomic nervous system. We’ve also explored the concept of heart rate variability. But the truly captivating aspect is the strong link between these two phenomena. Let’s investigate further.
Although this is a brief video, it’s crucial to our understanding. As depicted in the overview, the brain is at the top, and we’ve learned about the sympathetic nervous system (fight or flight) and the parasympathetic nervous system (rest and digest). When the amygdala perceives a threat, it activates the sympathetic nervous system, as we’ve seen in previous videos. What we haven’t discussed is how the sympathetic nervous system decreases HRV, while the parasympathetic nervous system increases HRV when you are calm.
At first glance, this might seem counterintuitive. However, consider it this way: when you’re stressed and preparing for action, your heartbeat must follow a strict cadence, resulting in less variability between heartbeats. Conversely, when you’re relaxed, your heart is at ease, and there’s no need for a rigid cadence between heartbeats, leading to higher HRV.
When the sympathetic nervous system is active, HRV is low. Long-term activation of the sympathetic nervous system, as seen in chronically stressed individuals, can lead to illness. On the other hand, an active parasympathetic nervous system not only increases HRV but also enhances resilience and performance.
Now that you’re familiar with HRV and its relationship to the nervous system, it’s time to start measuring your HRV. You can assess your stress levels both subjectively and objectively, with the latter being a continuous, 24/7 measurement.
