Programming

I play guitar but i learned before getting into the career. I don't play much anymore but i think it depends what your level is and what you're trying to learn. Rocking along to songs is a way to blow off some steam but you're also practicing by playing. If you're just learning chords or strumming / picking patterns, you can sit back and practice them while watching tv or doing whatever what doesn't involve hands. It can be relaxing too, just do it slowly, don't push yourself and you will learn the muscle memory either way.

Assuming you're learning acoustic like me. Learning electric guitar, solos and music theory may be different.