Tonic Levels of Physical Activity Stimulate Your Vagus Nerve

“Tonic” refers to a state of continuous activity that exists in both the sympathetic and parasympathetic divisions of the autonomic nervous systems under a wide variety of conditions. Strictly defined, “autonomic” or “autonomous” signifies independence or freedom from control by external forces.

Tonic levels of aerobic activity stimulate the vagus nerve, which reduces stress responses linked to "fight-or-flight" mechanisms. Heart rate variability (HRV), which is the assessment of fluctuations within beat-to-beat intervals, is also improved by tonic levels of mild, moderate, and strenuous physical activity.
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Overtraining or doing too much aerobic exercise lowers HRV and reduces vagal tone. While completing varying intensities of aerobic exercise, everyone will have somewhat variable degrees of Rated Perceived Exertion (RPE). What you find simple may appear difficult to others, and vice versa.

There's a long-running dispute regarding how intensely someone should exercise in order to improve subjective and overall well-being. Unfortunately, among some professionals, there is still no clear consensus. Some research suggests that moderate-to-vigorous physical activity (MVPA) is the most beneficial, while others suggest that low-intensity exercise is preferable.

Pleasure is sought by all animals, including humans. As a result, if exercise is perceived as an unpleasant or "painful" experience, you are more likely to avoid it. It's critical to select a physical activity that you enjoy and then exercise at a "tonic level" of intensity that makes you feel good, according to the universal principle of the "Pleasure Principle." Of course, your level of intensity will likely change from day to day and throughout your life.

While figuring out your ideal exercise routine, we encourage you to remember to include stretches into your routine. It can help prevent many injuries. Stretching before and after you exercise are both important for the wellness of your body. Massage can also provide benefits in recovery time, especially after intensive exercise.

Source: https://www.psychologytoday.com/us/blog/the-athletes-way/201705/tonic-levels-physical-activity-stimulate-your-vagus-nerve