You may want simple carbs for a burst of energy. Keep in mind we eat complex carbs because they digest slowly. This allows the body to use the glucose as energy instead of storing it as fat. On the contrary simple carbs are broken down very quickly and rush your body with sugar which spikes your glucose level. If you’re not doing something to burn the glucose it’s stored as fat. So you may want simple carbs before or right after an intense workout to spike your glucose levels but other than that you want to stick to complex carbs.
Pre/Post Workout simple carbs are very helpful but make sure their high in protein and low in fat.