7. Do Push-ups/Squats by far one of the most effective exercises to burn calories. If you don’t have enough time, patience or equipment, just get on the floor with simple push-ups and squats. Push-ups and squats require only 15 minutes of your time and the results will make it look like you have been spending some serious time sweating in the gym. Both are fantastic exercises to burn fat, tone arms and legs in no time.