Whether endurance or weight training. No matter. Actually, you should always eat something small before you take any decent physical exercise. Your body needs this "support".

Whether banana, protein bars or other power snacks. In a healthy mass your body simply needs it! After all, what should it use if you haven't eaten for more than ten hours? Smart as the body is, it takes energy where it shouldn't. The consequences after training are ravenous appetite attacks that can destroy your whole training.