Tough love is way overrated, but the truth is, sometimes a kick in the ass is the best medicine for what ails you. For a jump in the fitness direction, check out personal trainer Susan Koenig of East Bay Agility. She's a drill sergeant, but in the nicest way. Clients of all levels find themselves doing stuff they didn't think they could do, like running stairs or pumping out push-ups. Her GO! group training meets at Cesar Chavez Park in Berkeley for six-week sessions; she offers personal training and a "learn to love running for non-runners" class, and she also teaches at the Berkeley YMCA. Koenig knows that physical fitness isn't just about bodies — it's about the mind, too, and if her clients' expectations of themselves have dipped because of past "failures," Koenig won't hesitate to point that out and offer fresh encouragement. "The real improvement," one of Koenig's students says, "is that she helps me try harder."