You are what you repeatedly do. Throughout the past month I climbed every day youth hill. It was mostly running with breaks of walking when I get tired. In March I decided to stop the sport and start another physical, but less intense activity. The result is that after a day performing various tasks in the real world I still had energy. The legs were calling out to run. They even ran alone.
Compare your body to a car. If you leave it somewhere what will happen - the battery will be drained, the tires will fall will begin the process of corrosion. The same happens with people. Heart convened that "machine" that works managing low and close to zero speed and gradually began to beat more slowly. This is why we get tired quickly.
Running is good for the whole body - hands, feet, heart, brain. When you run, his heart began to beat faster. Switches to high speed. Thus every cell in the body is charged with a much needed oxygen. Increasing the productivity of the brain. The idea is clear, it is easier to focus on tasks without the need for the assumption of stimulating substances such as coffee, cola, chocolate.
Running is not the only option of physical activity for lifting alertness and energy - many options;). The important thing is not to abandon ourselves because the body will start to rust inside.