Exercising in the morning burns more fat?? June 21 2015
If fat loss is one of your main goals, exercising on an empty stomach such as first thing in the morning may encourage your body to burn slightly more fat for fuel.
According to research, insulin levels are at their lowest and glucagen levels are at their highest after an overnight fast. This increases the amount of fat that leaves your fat cells and travels to your muscles, where the fat is burned. Now for the down side - you will probably fatigue sooner or drop your exercise intensity and therefore end up burning fewer calories-and less body fat!! If you are looking to increase your performance in the gym, exercising in a fasted state will almost certainly reduce your endurance.
On the other hand if strength and muscle mass are important goals, my advice is you would be better off exercising after a light meal. After an overnight fast, when muscle glycogen and blood glucose levels are pretty low, your muscles will tent to burn more protein for fuel. So you could end up losing hard earned muscle.