Simply put, everything we feed our bodies provides energy. The energy quality differs and depends on multiple factors, including the number of nutrients.
Energy is exerted every time we move. In fact, our brain alone takes up a quarter of our energy consumption. Now, imagine how much energy we need when we're moving our bodies in new ways and strengthening our muscles. We not only need energy but a healthy intake of quality and quantity - just the right amount of food and the right type before we begin working out.
It is important to consider the duration between your last meal or snack, and your workout type and intensity. Our bodies need to process and absorb vitamins and minerals.
Feeding the body a considerable amount of complex carbohydrates is a great way to go. Carbohydrates are made up of fiber, starch, and sugar. Food that has more fiber and starch, rather than sugar, may likely be a complex carb and have a higher nutrient quality.
That is a great food choice before your workout - complex carbs, in lieu of simple carbs, such as a baked good with added sugar.
Here is a list of food types to consider
Apples
Bananas
Oatmeal
Oranges