I see two ways to hack the need for validation, but they sort of run in opposite directions: creating, or hanging around, a community where you're the most or one of the most competent person around. This helps a lot because validation is fluid, is not necessarily related to romantic appreciation but also to social status.
A second way that I sometimes practice is to go in a place full of attractive people and begin looking each in the eyes, smiling. More often than not, they will reciprocate and it doesn't take much to fill your romantic validation meter, we are (at least, males are) very good at self-deluding.
Bonus tip: calisthenics or a home-gym are effective ways of training, you do not need to necessarily run to train alone.