As little as 15-20 minutes of intensive resistance exercise can help to flatten your belly in 45 days, “The first set of an exercise switches on the hormones that control your metabolism,.
It depends on how hard you work. Fletcher says that you can burn up to 20 calories per minute with a high-intensity interval workout.
As Rob Fletcher says, the key is consistency. Try to complete some type of activity each day to burn enough calories, so that you reach and maintain a healthy weight.