Chen Taijiquan

You are burning when your body is exercising within its aerobic range. You should be burning fat instead of carbohydrates after 20 minutes in your aerobic zone. Your muscles will continue to burn fat after both aerobic or anaerobic (muscle training) exercise. According to recent studies in regards to fat burning, a moderate intensity workout works best. If you are exercising at a heart rate equal to about 75% of max, your fat burning will be between 0.5 grams - 1.0 grams of fat per minute for a 45kg to 90kg(100 to 200) pound person respectively. Fat burning will increase by another 10% roughly after one hour of continuous exercise - for fit people. Those less fit will burn more sugar and less fat.