These six Gosvāmīs, they were deputed by Lord Caitanya to discuss this science. They have written immense literature about it. You see? So you'll be surprised that they were sleeping only for one and half hours daily, not more than that. That also, sometimes they forego. You see. Now, so much busy in spiritual activities, kṛṣṇotkīrtana-gāna-nartana-parau... So spiritual life is so sublime and so invigorating that you won't feel fatigued. Won't. Once... You have to be engaged. And as you are engaged actually in spiritual life, you won't feel fatigued. You'll be fearless, and your life will be always blissful. These are the symptoms.