" Those who do contemplative retreats in hermitages are far from doing nothing, since they are constantly engaged in training their minds, but there is no ‘noise,’ no ‘waste’ to eliminate, no stress to cure, no chaos to reorganize. This means that there is less to repair during sleep and the sleep quality of meditators is deeper. "

― Arianna Huffington , The Sleep Revolution: Transforming Your Life, One Night at a Time