"Meu amigo nunca se exercita."

Translation: My friend never exercises.

[Koreatown]

I don't understand the "se" in this sentence... it's like he never exercises [himself]?

[Paulenrique]

Yep. This verb is called reflexive (when the consequence of the action is on oneself). So, "eu ME exercito", "nós NOS exercitamos"...it is the conjugation for the verb exercitar-se.