The Human Body

One great first step towards getting in shape is to understand the human body and how it works. A complex and sophisticated machine, the human body accomplishes extraordinary feats – and we’re not just talking about athletes who can break the four-minute mile, we’re talking about every human body that breathes in and out.

Your body has a series of failsafe devices to make sure that whatever happens, you can keep running. Like any machine, your body needs fuel to function, and the fuel you use is glucose. All the food you eat is broken down into glucose, which it burns to give your muscles energy to move. The oxygen you breathe in through your lungs is transported around your body in your bloodstream, and releases energy into your blood cells through a chemical reaction with the fuel molecules. When your body can’t get oxygen to your cells in time, it releases energy from stored carbohydrates instead, which is useful for bursts of energy, although it does create more waste, in the form of lactic acid, for your body to dispose of afterwards.

Your lungs, heart and blood circulatory system look after the process of generating energy and carrying both fuel and messages to every part of your body. Your nervous system senses changes in your environment or in your internal organs and sends messages to your brain about them – so if you touch a hot saucepan, your brain knows you need to take your hand away, fast. Your bones and muscles provide your body’s framework and enable you to move, and your hormones send instructions around your body to stimulate you to grow, and keep all your systems operating on an even keel.