The Story of Metabolism

Updated on July 28, 2007

Once upon a time, there was a little muscle cell, and it needed energy to move. It got it's energy by building a fire in its fireplace (called a mitochondria) and using the energy from the fire to move.

The little cell first started a fire by burning some kindling (also known as glucose or sugar) that it had laying around. The kindling burned easily, but it also burned quickly. It wasn't long before the kindling was burned up and the fire went out. The little muscle cell decided that a big log (also known as fat) would burn longer and promptly sent a messenger to the logging company to have some logs delivered.

When the little muscle cell got its logs, it quickly threw them into the fireplace and tried to light it on fire. Unfortunately, the log wouldn't light. The little cell realized that it needed some kindling to get the fire started, so it lit the kindling, and as soon as the fire was going, the little cell threw the log on the fire. The little cell looked at its burning log with pride.

One day the little muscle cell's master (also known as the brain) ordered the little cell to move more than it normally did. Apparently the brain decided that the whole body was going to try something called "exercise." The little cell needed energy fast, so it started burning its kindling and sent out its messenger to the logging company (also known as that big budge of fat that you hate) to ask for more logs.

The logging company's reply was not what the little cell wanted to hear. The logging company said that the little muscle cell had already received its normal order of logs and wasn't going to send out anymore today. The little cell had no choice but to continue burning its kindling without the log, but the fire didn't last long. As soon as the fire died out, the little muscle cell stopped moving, and the body just couldn't exercise anymore. The brain was not happy about this because it had expected much more movement from the little muscle cell.

When the brain finally stopped telling the little muscle cell to move, the little muscle cell decided that it needed to make plans to deal with this situation if it happened again. The cell sent its messenger back to the logging company to negotiate, and the logging company agreed to send out one extra log if this "exercise" situation happened again.

Sure enough, the next day, the brain ordered the little muscle cell to move again for another session of "exercise." The little muscle cell began to burn its kindling and sent out its messenger to the logging company, and as agreed, the logging company sent back a single extra log.

The log was immediately placed on the fire, and it burned much longer than the kindling did, but not long enough. The fire died out, and the little cell couldn't move anymore. Again, the brain was not happy.

The little cell sent its messenger back to the logging company for renegotiation, and this time the logging company agreed to send back two extra logs if this "exercise" happened again, but they would only send the second log after the first log was used up.

Sure enough, the "exercise" session happened again the next day! The little cell received its two extra logs, but it still wasn't enough, so it sent its messenger back again into renegotiation. This exercise-negotiation cycle kept happening every day that the brain told the little cell to exercise.

As negotiations continued, the little muscle cell and logging company eventually came to an agreement that allowed the little muscle cell to get as many logs as it needed immediately after the "exercise" session began. Because of this agreement, the little muscle cell was able to keep moving as much as the brain ordered.

It wasn't long before this "exercise" thing started to happen all the time, and one fireplace just wasn't enough to keep up with the demand, so the little muscle cell installed some additional fireplaces, so it could burn even more logs at the same time.

Eventually, the little muscle cell was receiving so many log deliveries that the logging company decided that they needed to have some extra roadways (also known as blood vessels) built to make sure all of the delivery trucks could get to and from the little muscle cell quickly. Everyone loved these new roadways because they dramatically improved everyone's efficiency and cut down the traffic congestion and commute time. The little cell loved burning logs so much that it burned logs even when the body wasn't exercising, so it was always ready to move. This made the brain very happy.

The Moral of the Story

• Don't expect to be able to run a marathon on your first day of exercising. It takes awhile before your various body parts will "negotiate" to share the necessary resources for the activity you want to do. Don't give up before those negotiations start making a difference.
• When you exercise, don't think about how much fat you're burning while you exercise. Instead, think about how much more efficient the fat burning process will be and how healthy other parts of your body are becoming because of the increased efficiency.