“Just watch someone who knows what they are doing.”The sage advice comes from Sam Fant as the music cranks up for Tuesday’s free community Zumba class in the August Knodt School cafeteria.In seconds, the former Trojan quarterback is doing moves with his hips that would have his former football coaches at Lincoln High of Stockton shaking their heads.But it doesn’t bother Fant. He knows better.Fant, who will lift weights occasionally with the Weston Ranch High football team and play hoops when he’s not taking one of the 9 a.m. Zumba and/or aerobics classes, offers the opinion that most football players would have a tough time keeping up with the ladies in class.He’s not joking. Years ago Mesa Verde High’s football staff in Citrus Heights — irked because they had a number of players in summer conditioning that thought they were in great shape — brought in the girlfriend on an assistant coach who happened to teach Jazzercise.