This will require your body to use fat as a source of energy instead of carbohydrates. Several articles I have read indicate that your body will use carbohydrates for the first 20 minutes and then it will need to use fat as a source of energy when you go past 20 minutes because it needs a long-term energy source. I take aminos, multi vitamins, creatine monohydrate, and glucosamine during my 12 week training cycle. The aminos and multi-vitamins assist with muscle recovery and endurance over a long training period. When you are training at a high intense level, your normal dietary food intake will be insufficient for your muscle growth and recovery.
Creatine is very useful to assist with muscle growth and training effort.
The only drawback with creatine is that it will cause your body to retain water weight more easily. Therefore, if you have to drop weight, I recommend you stop your creatine intake about 10 days before your competition. This is recommended because it will be harder for you to drop weight and when you do get at your competition body weight your electrolytes maybe out of balance, which may cause cramping during your competition. I have personally experienced this type of cramping. The glucosamine is used to assist with joint recovery.