Nutrisport ATP Muscle Fuel 4:1:1 supplement that offers complex carbohydrates with creatine & hydrolysed whey protein. Creatine is known as the energy fuel for athletes & although a small quantity is produced naturally by the body, with some being found in red meat & fish, it can be best to supplement your diet with nutrition products such as the Nutri Sport ATP Muscle Fuel. Taking creatine with a complex carbohydrate, as with Muscle Fuel, increases the production of insulin & therefore improves the absorption of creatine.