Food as fuel
Everything changed the day I understood that if I was to become a runner, I would have to run with the body I had. Almost without warning I began to think of food as fuel for my body, and not comfort for my soul. Food wasn't a new diet or a new program to lose weight. Food was part of the overall metamorphosis of my body from vessel to vehicle. As I wanted to do more with my body, I wanted to provide the fuel my body demanded.
The body has three sources of fuel: carbohydrates, protein, and fat. Carbs, as they are called, are the fast-acting, fast-burning fuel. Your body uses carbs quickly; consequently they need to be replaced often. Your body cannot store vast amounts of carbohydrates, so they are used or converted into a form that can be stored. Carbohydrates include breads and cereals, fruit and vegetables, and anything else that seems "starchy."
Proteins burn more slowly than carbohydrates, but more quickly than fats. Sources for protein include meats, nuts, beans, and dairy products. Protein is found on the body as muscle.
Fat is everything that isn't protein or carbohydrate. Fat is exactly what it is called: fat. If it looks like fat and feels like fat, it is fat. The good news is that the body is very good at storing fat. We would never have survived harsh winters or food shortages if we weren't good at storing fat. The bad news is that our bodies are good at storing fat even if there is no shortage of food.
The key is to work with your body. You've got to provide the right balance of carbohydrates, proteins, and fats, combined with activity, that your body needs. Many dietary guidelines and exercise programs have features that may work for some of us, but not all of us. Trust yourself. Trust your body. Find your own balance.
Transforming a body that has become accustomed to inactivity into one that willingly, even eagerly, runs does not happen overnight. At first, your body rebels. It sends messages, by way of aches and pains, that it is not pleased with the new program. It resists the change. It gets tired quickly and it waits impatiently for you to give up.
Before long, though, your body begins to get the message and it begins to adapt to the new stresses being placed on it. It does so by getting stronger. By carefully alternating between stress and recovery, your body actually becomes both more and less than it was.