At my first job, I used to grind out work, staying hours past when most people went home. For me, this was the best time to actually get work done without the distractions. But I remember my project manager, who was twice my age, getting pissed off at me and telling me to go home. When I was completing tasks and sending off emails, I was just giving her more work to do that night. So that would be overperforming I think.