According to most scientists, you should exercise at least 30 to 60 minutes a day. This means that you will have burnt the right amount of calories, so that you can compensate for the rest with food. A human body requires at least 2000 cal a day to function properly. When you exercise at least 30 to 60 minutes a day, you will be burning a decent amount of calories, depending upon how intense your workout is. If your workout is very intense, your body actually continues to burn calories, even when you’re done with the workout. I feel that this is amazing when it comes to expecting weight loss. You will definitely lose an insane amount of weight, if you do high-intensity cardio.