Vagal tone refers to the activity of the vagus nerve, which is a key part of the parasympathetic nervous system. This nerve helps regulate various bodily functions, including heart rate, digestion, and respiratory rate. A higher vagal tone indicates better regulation of these functions, promoting relaxation and reducing stress. Measuring vagal tone can provide insights into a person's overall health and emotional well-being. Techniques such as deep breathing, meditation, and yoga can enhance vagal tone, leading to improved resilience against stress and better emotional regulation.