(Repeat after us.) One, two, three, four. We don’t know, but we’ve been told. That our gym routine is getting old. Shanon B. Smith is her name — a trainer based in Burlingame. She’s got a studio in Pac Heights; on the Lyon stairs she’ll test your might. Or to your home she’ll come and go, leading circuit training and cardio. With bands and balls, she’ll work your core. After jumps and lunges, you’ll beg for more. For diet, Smith takes a holistic approach. And works in tandem as your nutrition coach. Tactics include behavior modification. (She’ll even tailor a workout when you’re on vacation!) One-hour sessions are never the same; she mixes it up to keep you in the game. Go it alone or with a group. Either way, she could lead a troop. Shanon B. Smith (415-370-0786 or shanonbsmith.com).