carry underwood 2“My favorite workout is Tabata,” says Underwood, 32 years old, “which I can do at home in about a half hour. I’m in love with it! It’s hard, but it really works. I choose seven different exercises, like squats, lunges, or push- ups, and do eight rounds of each—20 seconds on, 10 seconds off for eight rounds. It really revs up my metabolism. When I’m done, I can handle anything.”