Jennifer Lopez maintains her age-defying physique a portion-controlled , mostly vegan diet and rigorous 90-minute workouts, Celebrity Health reported.
"She does the Tracy Anderson Method, which includes muscular structure work and between nine and 13 different exercises that change every 10 days, and dance aerobics as well," said Anderson.
"I keep [her butt] toned and in position. We do planks, moving the legs and butt at different angles."
Lopez, who lost 40 pounds after giving birth to twins in 2008, tries to stick to a 1,200 to 1,400-calorie-a-day diet. She said her No. 1 diet and weight-loss secret is portion control. "Just like anybody, I try to watch what I eat," she said. "There's no big science to it.
Anderson's workouts with JLo typically combine high-intensity cardio dance exercise with light strength-training using body weight and high repetitions done with tiny hand weights (three pounds maximum).
"While bulkier muscle looks OK on women in their 20s and 30s, it doesn’t age well," said Tracy, who once trained the super-ripped Madonna.
Anderson's exercise tips contradict the advice of most fitness experts, who recommend that women lift heavy weights and should not be concerned that weight-lifting will bulk them up.
Earlier this year, Tracy was slammed after saying women shouldn't take spinning classes because they give women huge thighs. "Spin may burn calories in the short term, but if that's all you're doing, it'll bulk up your thighs," said Anderson.
Most weight-loss experts disagreed with Anderson. "It's so wrong and there is so much data that clearly shows otherwise," said exercise physiologist James O. Hill.
Whether you agree with her methods or not, there's no denying Anderson has sculpted some of Hollywood's fittest bodies, including Gwyneth Paltrow, Victoria Beckham and Kim Kardashian. Anderson shared her weight loss tips in her book, Tracy Anderson's 30-Day Method.