If somebody greets you with 'SERWUS', RUN forest RUN!!! He is stupid, fag or fucked.
Anyway you don't wanna have friends who say 'serwus' (unless they are 60+ years old).
I had a guy say it today. He came to the school I teach at and he is one of the guys I play football with. He always says it.
I'd be very worried in your case. Though in football a good running speed is good.