Question: How can we strengthen our subtle nerves?Sri Chinmoy: Sometimes our subtle nerves are weak, so we have to strengthen them. When you meditate, for a few minutes, say four or five minutes, consciously breathe in and out, inhale and exhale, very, very quietly. This is one way we can strengthen our subtle nerves. There are other ways, but this is the easiest way, the most effective way: to sit properly and breathe in and out as quietly as possible. This will help the subtle nerves become strong.
Sri Chinmoy, Sri Chinmoy answers, part 17, Agni Press, 1999