How big is your tank?

As a society, being overly fat is a condition that is becoming the norm rather than the exception.  As a result, understanding why this is a problem seems to be becoming more difficult for people to understand.  As is the case with many concepts in exercise physiology, I often look to the mechanical world for practical examples to help explain these concepts.
Think of your muscles as the engine in your car, and your fat as the car's gas tank.  In the car, gas is pumped from the tank to the engine where it is burned, and the resultant energy used to move the car.  Essentially the same process occurs in the body.  Fat is moved from the adipose tissue via the blood, to the muscles, where it is burned for energy to move the body.  In a properly designed machine, the size of the gas tank is proportional to the size of the engine.  For example, a motorcycle might have a 3 gallon gas tank and a relatively small engine, while a car has a much larger engine and around a 20 gallon tank.  In the car, the larger engine is matched with a larger tank.  Finally, in something like a large truck, the much larger engine requires a much larger tank.  Imagine the consequences of coupling a gas tank from a school bus to a motorcycle.  Because of the bike's relatively low engine power, the motorcycle would struggle to haul around such a heavy volume of fuel, and doing so would soon wear out the engine.  Furthermore, the performance of the bike would be terrible, as it would be straining simply to move it's own weight.  The same principles apply to the human body.  In addition to a host of metabolic problems, lugging around a large amount of fat hampers our physical performance and, over time, causes excessive "wear and tear" on our joints, ligaments and other musculoskeletal structures.  
Our response to this is typically to move less, which only results in a higher accumulation of fat.  The next time you look in the mirror, take note of what you see, or more importantly, what you don't.  If all you see is "tank" and no "engine", it's time to shift your exercise program and diet so that conditions are favorable for building muscle and losing fat, which will be the subject of next week's blog.  Have a great weekend.

Miller