The 32-year-old actress has shed many pounds by following the diet programme a few years ago, reported People magazine.
"Sometimes I set the timer on the stove and run up and down my steps until it goes off. You don't even need to go to the gym. Set the timer or microwave for 15 to 20 minutes and you'll work up a sweat," Hudson said.
The 'Spotlight' hitmaker, who has a four-year-old son, David, with her fiance David Otunga, is currently trying to get her fitness routine back on track after splurging on calorie-laden treats over the festive season.