Mahakumbh 2025: In the world of ascetics, the most rigorous spiritual practice is 'Hathyoga.' As part of their devotion to their guru, ascetics typically commit to a specific type of yoga for 12 years, which is known as Hathyoga. At the Mahakumbh, many such ascetics, known as Hathyogis, have gathered. NDTV spoke to some of these Hathyogis. At the Aavahan Akhara, NDTV met two such sages who are deeply immersed in their spiritual practice, having taken a 12-year vow of Hath Yoga.