Zen master Hakuin inspires us to develop fortitude
Hakuin’s early extreme exertions affected his health, and at one point in his young life he fell ill for almost two years, experiencing what would now probably be classified as a nervous breakdown by Western medicine, though the symptoms were similar to Kundalini.
He called it Zen sickness, and sought the advice of a Taoist cave dwelling hermit named Hakuyu, who prescribed a chakra visualisation practice which eventually relieved his symptoms.
From this point on, Hakuin put a great deal of importance on physical strength and health in his Zen practice, and studying Hakuin-style Zen required a great deal of stamina. Hakuin often spoke of strengthening the body by concentrating the spirit, and followed this advice himself. Well into his seventies, he claimed to have more physical strength than he had at age thirty, and was able to sit in zazen meditation or chant sutras for an entire day.