SB 7.3.19
naitat purvarsayas cakrur
na karisyanti capare
nirambur dharayet pranan
ko vai divya-samah satam
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Even saintly persons like Bhrgu, born previously, could not perform such severe austerities, nor will anyone in the future be able to do so. Who within these three worlds can sustain his life without even drinking water for one hundred celestial years?
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
It appears that even if a yogi does not drink a drop of water, he can live for many, many years by the yogic process, though his outer body be eaten by ants and moths.