In the gmara kidushin 81b according to the translation http://www.dafyomi.co.il/kidushin/points/kd-ps-081.htm the following story happened.
(h) Whenever R. Chiya bar Ashi would fall on his face in supplication, he would ask Hash-m to save him from the Yetzer Ra. Once, his wife heard this. She was surprised, for he had separated from her a long time ago due to old age.
(i) One day while he was learning outside, she disguised herself and passed in front of him repeatedly. He asked who she was. She said that she was Charusa (the town harlot). He asked to sin with her.
(j)When he returned home, he wanted to kill himself. His wife convinced him that it was her. Still he fasted the rest of his life, for he had intended to sin.
What was the motivation of Rav Chiya to separate from his wife and praying every day to be saved from the yetzer hara instead of living a healthy marriage?