Śivasaṃhitā 3.44

A practically precise instruction: prāṇāyāma should not be practiced either immediately after eating — when apāna vāyu is working on digestion — nor with intense hunger — when hypoglycemia distracts attention. The budhāḥ (the wise, the experts) know this rule because they have experienced the consequences of violating it: nausea, dizziness, mental dispersion, or abrupt interruption of practice.

Sadyo (immediately, at once) underscores the immediacy of the harm: it is not about avoiding practice for two hours after eating, but about that precise moment when the stomach is full and prāṇa is occupied transforming food. Kṣudhita (hungry, with acute appetite) designates not fasting but the hypoglycemic state that interferes with the concentration necessary for kumbhaka.

The positive consequences of correct practice are equally concrete: liberation from disease, absence of putrid perspiration and intestinal parasites. This last promise — perhaps surprising to the modern reader — is coherent with the āyurvedic view connecting the presence of parasites to digestive fire imbalance. The yogin who purifies their agni through prāṇāyāma creates a hostile environment for pathogenic organisms.