I mentioned a few weeks ago how researchers have been trying to electrically stimulate the vagus nerve, which is now thought to help treat everything from anxiety to depression.
In this study, researchers from the University of Auckland found that the vagus nerve, plays a significant role during exercise. Contrary to the prevailing understanding that only the ‘fight or flight’ nervous system is active during exercise, this study shows that activity in the vagus nerve actually increases. This helps the heart pump blood more effectively, supporting the body’s increased oxygen needs during exercise.
Interestingly, especially for people I know who have heart failure, they also identified that the vagus nerve releases a peptide which helps dilate coronary vessels. This allows more blood to flow through the heart.
The vagus nerve, known for its role in ‘resting and digesting,’ has now been found to have an important role in exercise, helping the heart pump blood, which delivers oxygen around the body.
Currently, exercise science holds that the ‘fight or flight’ (sympathetic) nervous system is active during exercise, helping the heart beat harder, and the ‘rest and digest’ (parasympathetic) nervous system is lowered or inactive.
However, University of Auckland physiology Associate Professor Rohit Ramchandra says that this current understanding is based on indirect estimates and a number of assumptions their new study has proven to be wrong. The work is published in the journal Circulation Research.
“Our study finds the activity in these ‘rest and digest’ vagal nerves actually increases during exercise,” Dr. Ramchandra says.
There is a lot of interest in trying to ‘hack’ or improve vagal tone as a means to reduce anxiety. Investigating this was outside the scope of the current study. Dr. Ramchandra says we do know that the vagus mediates the slowing down of heart rate and if we have high vagal activity, then our hearts should beat slower.
“Whether this is the same as relaxation, I am not sure, but we can say that regular exercise can improve vagal activity and has beneficial effects.”