Especially during the school year, the first lady gets up at 4:30 a.m. or 5 a.m. to work out before her kids wake up, she told iVillage, the women's website where she is serving as a guest editor this week, with a theme of "Rev Up Your Back-to-School Routine."
"Barack and I work out every day," the first lady told the site in an interview to appear online this week. "I usually get to the gym before he does. But he is usually there either in the middle of my workout or right at the end. And we're watching 'SportsCenter' and we're catching up. That's why I know so much about sports ... and you start having an opinion about (New York Jets quarterbacks Tim) Tebow and Mark Sanchez."
If she's on the road, Mrs. Obama often brings a jump rope, she adds. "If I don't have a rope or space, I might do a 30-minute routine that includes a minute of jumping jacks alternating with a minute of push-ups, then some sit-ups. You take a 30-second break and do it again."
The first lady also tells the site what her family's food weaknesses are.
For Malia, it's juice: Her mom has suggested she cut back by drinking water or mixing it with seltzer. And for Barack, it's chips with salsa and guacamole - or nuts, like peanuts, almonds and pecans. "He kind of shakes them in one hand and creates, like, a little dispenser with his index finger where he can just pop them in his mouth. And I kind of imitate him when he does that. But he's a nut guy. That's what he's munching on all the time."
As for the first lady? "French fries, which is good because you can't just have french fries around, so that's helpful," she says. "But if there are french fries in the vicinity, I'm done. It's over."
The first lady is the first of a series of planned guest editors at iVillage, which is part of NBCUniversal.