“Cardiovascular fitness and exercise capacity are strongly associated with high resting vagal tone”
The vagus nerve gets a lot of attention. And for good reason. But you don't have to become a monk to activate it.
Of course both would be best. But don't underestimate the power of exercise to improve mental health.
https://www.ahajournals.org/doi/10.1161/CIRCRESAHA.123.323017