What does Christopher Vo — one of the principal dancers in “Come Fly Away” — do to take a break from the stage? Dance some more. In addition to being a professional hoofer, Vo’s a Zumba instructor who’s so devoted to the fitness program that he can’t stop. So even though he’s on the road with the national tour of the musical featuring Frank Sinatra tunes (at the Kennedy Center April 18-29), he’s still finding opportunities to teach. That includes in Washington, where he has two classes lined up: today at Equinox Bethesda at 10:45 a.m., and April 26 at 10:30 a.m. at Equinox Tysons Corner. If you attend, don’t be intimidated by other folks in the room, many of whom are likely to be his castmates. “Zumba is really for everyone,” says Vo, who considers Zumba a critical part of his “upkeep routine” for his performances. “The whole show is 80 minutes, with no intermission. It’s a sprint, just like a Zumba class,” he adds.