Those who were old (pra vayasah) became strong and energetic.

Uddhava and others, the associates of the Lord, who are the protecting deities worshipped during arcana, could not be the elderly inhabitants. The elders were ancient members of the Andhaka and other families. sa kathaṁ sevayā tasya kale na jarasaṁ gataḥ pṛṣṭo vārtāṁ pratibrūyād bhartuḥ pādāv anusmaran How could Uddhava, who did not age because of his service to the Lord, when asked by Vidura for news about Kṛṣṇa, reply, since he began immediately thinking of the Lord’s lotus feet? SB 3.2.3 This statement of Vidura is ultimate proof of Uddhava’s continual youth. The older members did not age, since they tasted the extraordinary qualities of Kṛṣṇa. His lotus face was like nectar. They drank that extraordinary face like nectar with their eyes. That face was also like a lotus. It was extraordinary because it was like nectar and a lotus. Continually drinking that face, they were endowed with youth and strength of body (bala) and senses (ojasaḥ). This indicates endowment of other qualities as well.

Their bodies were made of eternity, knowledge and bliss. Among them, generally they did not age since they were avatāras of associates of the Lord. Or some of the Andhakas etc. were old in years, but youthful. They were eternally situated like this (āsan). They had physical strength (bala) and alert senses (ojasaḥ) or energy. They drank with their eyes the sweet beauty of his face. Their eyes were like cups for tasting the nectar, the highest bliss, which destroyed all anarthas. They did this constantly, being very close at all times (muhuḥ). Or they were constantly youthful, with strength of body and senses.